|University of Regensburg, Germany
||#01 - Tomer Czaczkes
||Hard limits to learning: ants can learn to ignore, but not avoid, pheromone trails
Learning allows animals to respond to changes in their world within the lifespan of the animal. However, many responses to the environment need not be learned. Depending on the level of learning flexibility an animal shows, such responses can either be modified by learning, or not. Many ants deposit pheromone trails to resources, and innately follow such trails. Here we ask whether ants can learn to avoid conspecific pheromone trails, when these predict a negative stimulus. Ants are allowed to repeatedly visit a Y-maze, one arm of which is marked with a strong but realistic pheromone trail and leads to a quinine solution, and the other of which us unmarked and leads to a 1.5M sucrose reward. After c.5 visits ants stop following the pheromone trail, but even after 25 exposures they fail to avoid it. Controls demonstrate that avoidance learning to neutral odours is rapid and strong. Surprisingly, all ants begin to favour just one side, a tactic which results in increasing food retrieval over time. These results demonstrates rapid learned flexibility towards an innate signal, but hard limits to this flexibility.
|New Jersey Institute of Technology, USA
||#02 - Yohann Chemtob
||Autonomous and biomimetic robot to study and modulate the collective behaviour of zebrafish (Danio rerio)
For a long time, biology research has explored animal behaviour through the use of robotic lures. More recently, technology has been used to investigate complex behaviours such as collective behaviour. In this communication, I would present the use of an autonomous and biomimetic robot to analyse the social behaviour of zebrafish (Danio rerio). To be integrated into a group of fish, it has been demonstrated that such robot must reproduce the behaviour of the target group. In the study that I will be presenting, we test the hypothesis that to modulate the behaviour of fish, here by driving a group towards a predefined choice, the robot also has to adopt some specific, fishlike behaviours. We developed and implemented a model of collective behaviour in order to generate a closed-loop interaction between the robot and the zebrafish group. Then, we used the robot to modulate the behaviour of zebrafish groups. Doing so, we were able to successfully reproduced leadership patterns with the robot and to modulate the use of space by reproducing bold/shy behaviours. With these results, we demonstrated that robots allow us to gain a deeper understanding of the functioning of specific collective behaviours.
|Swedish University of Agricultural Sciences, Sweden
||#03 - Michael Bertram
||Disruption of male mating strategies in a chemically compromised environment
Pharmaceuticals are accumulating in environments globally. This includes trenbolone, a growth promoter that enters waterways in agricultural run-off. However, whether and how drugs like trenbolone impact complex behaviours in wildlife remain largely unknown. We exposed male guppies (Poecilia reticulata) to trenbolone and compared the response of exposed and unexposed males to sequentially presented large and small females. Due to a positive size-fecundity relationship, larger females are generally expected to be preferred by males. While we found no evidence that the size of a previously encountered female affected the amount of mating behaviour performed by males during the second presentation, males from both exposure treatments conducted more frequent courting events towards larger females during both presentations, suggesting an absolute preference for greater female size. Further, across both presentations, trenbolone exposure caused a shift in male mating strategy towards increased sneaking behaviour, although male sequential investment into mating effort was not impacted. Our findings contribute to a growing understanding of impacts of pharmaceuticals on wildlife behaviour.
|University of Wuerzburg, Germany
||#04 - Daniela Römer
||The influence of ant worker aggregation on the emergence of collectively excavated nest structures
Ant nests consist of a complex system of tunnels and chambers that are excavated through a collective, self-organized process. It is an open question how a workers simple behavior leads to the final, intricate architecture of a nest differentiated into chambers and tunnels. We examined whether worker aggregation at a digging site, i.e. the spatial distribution of workers, guides tunnel and chamber emergence in the leaf-cutting ant Acromyrmex lundii. In the laboratory, worker aggregation was recorded for 48 h in a digging arena. Differences in the extent of aggregation at the beginning of excavation were achieved by presenting workers with either a small or a large available space as the starting point. The resulting chamber and tunnel volumes were measured, and aggregation during excavation was quantified. The number of workers inside the nest structure was similar in the low and high available space setup. When worker aggregation was dense because of the reduced available space, most of the digging activity was allocated to chamber enlargement, with less and delayed tunnel excavation. When aggregation was loose because of the larger available space, ants only slightly enlarged chambers, but excavated more tunnels, which were also initiated earlier. This shows that the simple factor of worker density at a site strongly influences the shape of collectively excavated nest structures. Chambers are excavated under high-density conditions until the concentrated collective digging at a site leads to a reduction in worker density beyond a given threshold value, resulting in consecutive tunnel excavation.
|University of Essex, UK
||#05 - Kareemah Chopra
||Investigating the social network of dairy cows
Understanding the herd social structure of housed dairy cows has the potential to reveal preferential interactions, detect changes in behaviour indicative of illness, and optimise farm management regimes. This study investigates the structure and consistency of the social network of a permanently housed commercial dairy herd throughout October 2014, using data collected from a wireless local positioning system. Herd-level social networks were determined from social proximity interactions (pairs of cows continuously within two metres for 80 seconds or longer), and assessed for social differentiation, temporal stability, and the influence of individual-level characteristics such as lameness, parity, and days in milk. We determine the level of inter-individual variation in sociality across the full barn housing, and for specific functional zones within it (feeding, non-feeding). The observed social networks were highly connected, and temporally varied, with significant inter-individual variation in daily interactions and preferential social assortment in the full barn and both functional zones. We find no clear social assortment by lameness, parity, or days in milk, but lame cows were shown to have a higher clustering coefficient in the non-feeding zone. Our study demonstrates the potential benefits of automated tracking technology to monitor the social interactions of individual animals within large, commercially relevant groups of livestock.
|Indian Institute of Science Education and Research (IISER) Tirupati, India
||#06 - Bishwarup Paul
||Investigating break-ins: Intraspecific brood theft in a tropical ant
Thievery is ubiquitous in the animal kingdom and several methods are employed by thieves in different taxa. Theft of brood is common in ants, and in this study we have explored the phenomena in Diacamma indicum, a primitively eusocial ant found in the tropics. Comparison of the manner in which these ants handle brood items and the speed at which they carry them in three different contexts – stealing brood from a guarded nest (theft, n = 42), procuring brood from an unguarded nest (rescue, n = 99) and transporting brood of own colony during relocation to a new nest (transport, n = 56) showed that thieves significantly reduced handling duration and increased their exit speed up to 3 folds in contrast to rescue or transport. Further experiments were performed to understand the cause behind this modification in behaviour. While the presence of foreign colony odour or foreign adults blocked from showing aggression did not account for the extent of modification, we concluded that the potential risk of aggressive interactions with foreign adults was causing the modification in behaviour. Though thieves (n = 37) repeatedly visited the victim colony, their latency to revisit increased significantly upon facing immobilization in their previous visit, which further corroborated our previous observation. The latency reduced significantly only when thieves were successful in their previous visit, suggesting regulation through a cost-benefit trade-off. In this comprehensive study, we reveal the simple rules of engagement between thieves and their victims.
|Pontifical Catholic University of Rio Grande do Sul, Brazil
||#07 - Debora Dreher Nabinger
||Acute and subchronic exposure of nickel chloride alters behavioral parameters in larval and adult zebrafish
Metals are some of the most toxic substances in the environment. Nickel is a heavy metal naturally present in the earth’s crust, but its increased levels lead to environmental contamination and can cause severe and irreversible health problems. In the present study, we evaluated the effects of NiCl2 exposure on cognition and behavior in larval and adult zebrafish. Larval and adult zebrafish were exposed to NiCl2 concentrations (0.025, 2, 5, and 15 mg/L) or water (control) in two treatment regimens: acute and subchronic. Larvae were exposed to NiCl2 for 2 hours (acute treatment: 5-day-old larvae treated for 2 hours, tested after exposure) or 11 days (subchronic treatment: 11-day-old larvae treated since fertilization, tested at 5, 8 and 11 days post-fertilization, dpf). Adults were exposed for 12 hours (acute treatment) or 96 hours (subchronic treatment) and were tested after the treatment period. In both regimens, exposed zebrafish showed concentration-dependent increases in body nickel levels compared with controls. For larvae, delayed hatching, decreased heart rate, and morphological alterations were observed in subchronically treated zebrafish. Larvae from subchronic treatment tested at 5 dpf decreased distance and mean speed at a low concentration (0.025 mg/L) and increased at higher concentrations (5 and 15 mg/L). Subchronic treated larvae decreased locomotion at 15 mg/L at 8 and 11 dpf and decreased escape responses to an aversive stimulus were observed at 2, 5, and 15 mg/L in all developmental stages. For adults, the exploratory behavior test showed that subchronic nickel exposure induced anxiogenic-like behavior and decreased aggression, whereas impaired memory was showed in both treatments. These results indicate that exposure to nickel in early life stages of zebrafish leads to morphological alterations, avoidance response impairment and locomotor deficits. Also, acute and subchronic exposure result in anxiogenic effects, impaired memory and decreased aggressive behavior in adults.
|Champalimaud Research, Portugal
||#08 - Clara Ferreira
||Behavioral and neuronal underpinnings of safety in numbers in fruit flies
Group living is thought to increase individual fitness through benefits in reproductive output, foraging outcome and predation protection. When surrounded by others, individuals can decrease their defenses enabling other beneficial behaviors such as foraging, as the group affords predator detection via social cues, concerted defense responses and predation risk dilution. However, while the detection of a threat through social cues is widely reported, the safety cues that guide animals to break away from a defensive behavior and resume alternate activities remain elusive. Here we show that fruit flies display a graded decrease in freezing behavior, triggered by an inescapable threat, with increasing group sizes. Moreover, using genetic and magnets for manipulations of the group composition, we determine that flies use the cessation of movement of other flies as a cue of threat and its resumption as a cue of safety. We further confirm the preponderant role of social information in breaking from freezing using a logistic regression model. Finally, we find that lobula columnar neurons, LC11, mediate the propensity for freezing flies to resume moving in response to the movement of others. By identifying visual motion cues, and the neurons involved in their processing, as the basis of a social safety cue this study brings new insights into the neuronal basis of safety in numbers.
|Cape Eleuthera Institute, The Bahamas
||#09 - Sebastian Hoefer
||Unique defensive display in a Bahamian snake
Snakes use a wide variety of antipredatory behaviours when faced with an apparent threat. Dependent on the perceived level of danger these behaviours can range from hissing, gaping, exuding musk, defecating or convolving to more extreme defensive strategies such as spitting venom, feigning death and even autohaemorrhaging. Autohaemorrhaging, or the deliberate ejection of blood, is a rare phenomenon in snakes and only widespread in the family Tropidophiidae. We aimed to deliver a highly detailed documentation of this unique defensive behaviour in a thunder snake (Tropidophis curtus barbouri) to provide more information on the process and function of this strategy. Immediately after capture, the snake defecated and discharged musk and after the persistent presence of a perceived threat, the snake displayed cephalic autohaemorrhaging. The onset of the display was extremely fast, < 3 seconds, and lead to a rapid blood-flooding of both eyes and exudation of blood from the mouth. Quickly after, < 5 seconds, the blood was re-absorbed and the eyes fully cleared. Overall, it took 6.7 seconds from the start of the cephalic autohaemorrhaging display to the full clearing of the eyes. The exact function of cephalic autohaemorrhaging is yet to be understood, however, its close association with other defensive behaviours and the role of autohaemorrhaging in other taxa, point to an antipredator response. While defecation and exudation of musk are often thought to render a snake unpalatable to a predator, this could be exacerbated by ejected blood. We also suggest that knowledge of the physiological processes involved in the very rapid onset and prompt stop of haemorrhaging in members of Tropidophis could have potential applications in medical fields.
|University of Turin, Italy
||#10 - Valeria Ferrario
||The motivations underlying food sharing in tufted capuchin monkey (Sapajus spp.)
In this work, we focused on testing one of the proximal mechanisms that have been proposed to explain cooperative behaviours such as the mutual exchange of goods and services in non-human primates. Specifically, we tested 'calculated reciprocity', according to which animals exchange food with conspecifics driven by the expectation of a return of the favour. We tested pairs of tufted capuchin monkeys (Sapajus spp.), a species known to readily exchange food, in three different experimental conditions. In the first condition, the partner, after receiving food from the subject in a first test phase, could reciprocate during a second test phase (Reciprocity). In the second condition, the partner did not have the possibility to reciprocate (Control). In the third condition, the experimenter gave the subject a quantity of food proportional to what the subject had given to the partner (Pseudoreciprocity). There was no difference in the amount of food transferred from the subject to the partner among the three experimental conditions. However, in the Pseudoreciprocity condition, capuchin monkeys increased the amount of food shared along successive test sessions. These findings suggest that the expectation of reciprocation did not motivate capuchin monkeys to share their food, although they were able to learn that sharing can lead to a reward.
|Aix-Marseille University, France
||#11 - Anna Verbe
||A study of aerial righting reflex in hoverflies Episyrphus balteatus
Hoverflies feature stunning aerial capabilities allowing them to orient themselves in various positions and orientations. Flies can land on surfaces no matter how tilted it may be, they can even settle upside down on the ceiling. When taking off from the tilted surface, flies must reorient dorsoventrally and stabilize body roll via active control of their flapping wings. Righting reflex has been shown to exist in mammalian and wingless insects but have never been studied so far in winged insects. After being released upside-down and dropped in free fall, hoverflies systematically rotate their body in roll once the wingbeats triggered. The aerial righting reflex is achieved by Episyrphus balteatus in 48.8ms (median value) within 6 wingbeats. As expected, a wing asymmetric stroke amplitude is at the origin of the body righting. We show that body rotates first at maximum roll speed as fast as 10000°/s and then that head rotates after a time lag of 16ms (median value) at similar angular speed.
|University of São Paulo, Brazil
||#12 - Veridiana Angeluzzi Jardim
||Is there a bias in the judgement bias test? Differential novelty responses in individuals with different personalities might affect test results
Cognitive judgement bias tests have become an important new tool in the assessment of animals’ internal states. In these tests, animals are first trained to discriminate between two cues, one associated with a positive and one with a less positive outcome. Then, they are confronted with an intermediate ambiguous cue to quantify the animals’ response reflecting their individual judgement bias, such as latency to approach. In many test settings, the presentation of the ambiguous cue implies the confrontation with greater novelty. We hypothesize that in such high-novelty settings, responses in the ambiguous arm might be biased by individuals’ personality, since different personality types can perceive and process novelty in different ways, an aspect which has been widely overlooked so far. We conducted a judgement bias test in a Y maze with male mound building mice, previously phenotyped for their exploratory tendency. The maze consisted in positive and less positive rewarded arms and, after the animals had learned this association, a new ambiguous arm was introduced. During the first ambiguous arm trial, more exploratory individuals displayed higher total and reversed locomotion, indicating intensive arm exploration, resulting in longer latencies for reward consumption. However, during the following two experimental trials, with decreasing novelty of the ambiguous arm, more exploratory individuals were faster than less exploratory ones in consuming the reward. Our findings suggest that in judgement bias test settings with high novelty linked to the ambiguous cue, results can be biased by the individuals’ differential personality-dependent motivation to explore novel environments. This suggests that results obtained in high novelty trials have to be carefully interpreted, or even discarded, since they could be affected by individuals’ novelty perception.
|Instituto de Investigaciones Forestales y Agropecuarias Bariloche, Argentina
||#13 - Laura Soledad Serrano
||Evaluation of plant consumption by two species of grasshoppers in northern Patagonia
Grasshoppers are one of the most representative groups of herbivorous insects in the steppe wetlands of northern Patagonia. These environments are important because of their environmental and ecological functions, including the provision of food resources for domestic livestock. Consequently, it is important to evaluate the effects caused by grasshoppers during outbreaks on crops and vegetation in natural areas, as well as the feeding behaviour that they present. In order to evaluate the diet of two grasshopper species from northern Patagonia, their host plant consumption was compared using the two most abundant species known to be included in their diet in the field (Juncus balticus and Trifolium repens). Dichroplus elongatus and D. vittigerum were collected during the summer season of 2018, in the province of Río Negro. A total of 63 adults of D. elongatus and 74 of D. vittigerum were collected using an entomological net. They were transported to the laboratory where they were maintained under semi controlled conditions. To evaluate feeding behaviour, a series of no-choice experiments were performed. After 48 hs individuals were fed with the plants J. balticus and T. repens. The amount of plant consumed (response variable) was obtained using the difference in plant weight from the beginning and the end of the experiment. The results exhibit significant differences in plant consumption between both species of insects. The amount of consumption of J. balticus was higher than T. repens for D. elongatus, but for D. vittigerum the opposite was observed. These results suggest that both species present different feeding behaviour preferences under semi-controlled conditions. The study of the diet of native insects that inhabit steppe wetlands in northern Patagonia provides useful information for pest control programs and contributes to the conservation and preservation of these valuable environments.
|University of Turin, Italy
||#14 - Caterina Ferrari
||Parasite load among factors driving Alpine marmot occupancy
Animal species inhabiting high mountain habitats developed strict adaptations to survive and cope with extreme conditions as for example cold temperature, long winter and short vegetative season. Among alpine rodents, Marmota marmota is a highly social species widely distributed in the alpine region. The presence of this species ranges between 1800 and 2700 meters, especially in alpine prairies, where marmot may found food resources, possibility to dig wide burrow system and good visibility for predator detection. However, this open mountain habitat is currently facing a reduction, due to the ascent of the forest line caused by both climate change and the abandon of domestic grazing. The Gran Paradiso National Park is running a long-term project on Alpine marmot in which more than 300 individuals have followed from 2006 onwards. Within this study, we investigated the drivers of marmot’s families settlement both along an altitudinal gradient and according to environmental and social parameters. An occupancy survey performed from 1900 m to 2800 m a.s.l. elevation gradient showed that families inhabiting areas at higher altitude benefit of a reduced parasite load compared to those living at lower site; this may compensate the harsher environmental conditions experienced at higher elevation. At a smaller scale a survival analysis showed that marginal habitats, and not open prairies, offer to alpine marmots a higher survival on the long term, probably derived by lower predation rate from aerial predator and less turnover among dominants individuals. This study highlights the double aspect of the long-term adaptions of Alpine marmot: living at high altitude may cost less in term of parasitism, while living in marginal habitats may increases survival. Therefore, the current change in the environment at the border between forests and open habitats may give a short-term advantage to the marmot; however, possible long-term adaptations are still to investigate.
|Queen Mary University of London, UK
||#15 - Shuge Wang
||Unlearned predispositions support fast generalisation
Young domestic chicks (Gallus gallus) are able to recognise and follow their mother soon after hatching. This can be challenging, as the mother hen may look different from a novel point of view, be partially occluded, and she might also look similar to other hens. However, chicks can recognise her even with limited experience, indicating a capacity to spontaneously generalise. It remains unclear what strategies are used in fast generalisation. The fact that even inexperienced chicks can quickly generalise suggests that experience is not required for effective generalisation. We hypothesise that generalisation may be guided by predispositions, which are spontaneous unlearned preferences toward certain features. We tested chicks using filial imprinting, which is a fast learning mechanism that restricts the preference of a chick to a familiar object, as our model system. Chicks were imprinted on a moving computer-generated shape that was either of a predisposed (red/blue), non-predisposed (yellow/green), or intermediate (orange/turquoise) colour. We then tested the chick’s preference towards the imprinting colour when it was presented along with a novel colour from the same continuum. Our results showed that chicks imprinted on predisposed colours spent more time near the imprinting colour when the novel colour was more distant from the imprinting colour. Chicks imprinted on non-predisposed colours showed no such generalisations. When chicks were imprinted on an intermediate colour, they preferred to stay near and follow the more predisposed colours, but not less predisposed colours that were equally distanced. In summary, our findings support the hypothesis that predispositions play an important role in fast generalisation when there is limited experience. We propose that generalisation may be facilitated by stimuli containing preferred features that orient the chick towards the stimuli. These experiments pave the way to understanding the connection between predispositions and fast generalisation in chicks, and in other species.
|Arizona State University, USA
||#16 - Andrew Burchill
||Ants, Dance, Evolution!: Extreme Locomotory Mimicry in Australian Jumping Spiders
Spiders of the genus Myrmarachne superbly mimic both the conspicuous movement patterns and physical appearances of ants. However, there is a diverse range of locomotory patterns across ant taxa. For example, "strobe ants" of the genus Opisthopsis seem to teleport from location to location: they exhibit bouts of blindingly fast movement punctuated by regular, periodic pauses. But can the spiders mimicking their visual appearance also keep pace? Using high-speed cameras, we demonstrate the first documented case of genus-specific locomotory mimicry in spiders. We analyzed the movement patterns of four ant species (two strobe ants and two ant species with typical movement patterns) and their spider mimics, characterizing features of their gaits such as period, rhythmicity, synchrony, etc. A PCA revealed that mimic movement patterns are more similar to their models than to their close relatives and vice versa. Strobe ant–mimicking spiders also modify their "antennal illusion" to match their unique models. Most spider mimics wave their forelegs to imitate the sweeping antennae of ants, but neither strobe ants nor their mimics display this stereotyped lateral movement in their appendages.
|Macquarie University, Australia
||#17 - Daniele Carlesso
||Hanging out to forage: dynamics of hanging chain behavior in weaver ants
Ants are renowned for their ability to cope with environmental challenges through collective behaviors. A striking example is that of self-assemblages: sophisticated three-dimensional structures that ants build with their own bodies by physically linking together. These structures are strikingly dynamic, self-heal when damaged and can rapidly adapt to environmental changes, without requiring any central control. Indeed, self-assemblages emerge from multiple low-level interactions among multiple individuals which can only access local information. Oecophylla smaragdina is an arboreal species of ants that builds self-assembled chains to cover vertical gaps in foraging trails. Previous studies have investigated the dynamics underlying the formation of these structures through a combination of behavioral observation and computer modelling. However, none of these studies explored how ants manage to maintain functional chains during foraging, which is likely to be the purpose for which chain formation has evolved. Here, I explore chain behavior by inducing sub-colonies of ants to form chains over a gap to reach an otherwise unattainable food source. Soon after recruitment starts, I quantify traffic volume and directionality, number of individuals involved in the chain as well as the time they spend as part of it, and the joining and leaving dynamics over time. Lastly, I investigate how gap length influence the ability of ants to successfully maintain the chain over time, for instance as a consequence of the higher number of individuals required to build longer chains. My study will provide useful insights into self-organization and swarm behavior, while furthering our understanding of the ecological function of self-assembled structures in eusocial insects.
|Max Planck Institute for Ornithology, Germany
||#18 - Pizza Ka Yee Chow
||Comparative cognition: innovation in two parrot species
One of the goals in comparative cognition is to reveal the similarities and differences in cognitive abilities and processes shared among taxa. This goal can be achieved by employing established methods and experimental procedures from a species of one taxonomic group to one or more species of another group, ideally without any modification. Here, we used two established food-extraction problems, that varied in their level of difficulty and that had been successfully solved by Eastern grey and Eurasian red squirrels, to assess innovative problem-solving ability in two species of parrots (blue-headed macaws and African grey parrots). All parrots solved both problems, with grey parrots outperforming blue-headed macaws in solving outcomes, despite showing comparable solving latency. At a between taxa level, we found that the level of difficulty of the two tasks reported in the squirrels was reversed for the parrots. Some possible explanations related to morphology, sociality, and food generalisation are highlighted.
|Arizona State University, USA
||#19 - Kirsten Traynor
||Social Disruption: sublethal pesticides in pollen leads to honey bee queen replacement & brood cannibalism
We conducted two field trials to test the impacts of sublethal pesticide contamination of pollen on foraging, brood rearing and colony health in Apis mellifera. The insecticide exposure combined the two most commonly detected insecticides (chlorypyrifos and fenpropathrin) in pollen, while the fungicide exposure combined two fungicides applied to blueberries (chlorothalonil and propiconazole). Colonies were fed these pesticide residues at sublethal doses for four weeks. Approximately 15% of commercial colonies and 6% of colonies surveyed for the National Honey Bee Disease survey exhibit pollen stores with similar rates of pesticide contamination, so these are field realistic doses.
|Pontifical Catholic University of Rio Grande do Sul, Brazil
||#20 - Rodrigo Zanandrea
||A transitory exposure to methionine changes the behavior and causes neurochemical impairment in adult zebrafish
The methionine (Met) is an amino acid involved in various metabolic processes. Increased plasmatic levels of this amino acid, indicate a condition known as hypermethioninemia. This pathological condition is caused by genetic causes, or non-genetic causes, such as hyperproteic diets, liver disease, or premature birth. Toxicological alterations of a persistent hipermethioninemia include myopathies, neurological dysfunctions, and liver diseases, all these well documented, but little is known about the effects of a transient plasmatic increase of this amino acid. The objective of this study was to evaluate behavioral parameters, oxidative profile, and neurochemical analyses in adult zebrafish during transient exposure to Met. Adult zebrafish were randomly assigned in two groups: Met group (exposure to 3mM Met for 7 days) or control group (water). After exposure, both groups were maintained for more 7 days in aquariums containing only water. Then, the animals were submitted to the novel tank test, social interaction test, mirror-induced aggression test, and inhibitory avoidance test. The brains were collected for evaluation of oxidative parameters and analyses of amino acids and neurotransmitters. Our results showed that exposure to Met caused a decrease in the distance moved and velocity whereas increased the time in the upper zone. The Met group showed a reduced aggressive behavior, whereas the social interaction did not change. Exposure to Met caused memory impairment. The CAT and SOD activities decreased in the Met group as well as the content of total thiols. Besides that, the transient exposure to Met caused a decrease in epinephrine and cysteine levels and increased carnitine and creatine levels. Our findings indicate that Met transient exposure causes behavioral changes, such as decreased anxiety, decreased aggression, and impaired memory. Also, the mechanisms underlying these effects are related to changes in the antioxidant system, amino acid, and neurotransmitter levels.
|University of California, Los Angeles, USA
||#21 - Dhiraj Ramireddy
||The function of crocodile hatchling (Crocodylus acutus) distress calls
This study attempts to describe communication and behavior among American Crocodile (Crocodylus acutus) hatchlings. By understanding when and why vocalizations occur, new insight can be found regarding extant relatives of crocodilians and extinct ancestors, including dinosaurs. In Cuajiniquil, Costa Rica, I observed two Crocodylus acutus nests and captured five crocodile hatchlings. I observed the captured hatchling and its siblings recording vocalizations and movement patterns. In response to a distress call to the captive, sibling hatchlings responded by vocalizing and in 3 of 5 trials, approached the captive hatchling. Acoustical analysis showed that the short successive response calls of free ranging siblings displayed similar frequencies and harmonics to the initial distress call. These results support the hypothesis that a distress call of a hatchling seeks help from sibling crocodiles. Both sibling behaviors, approaching a predator and echoing a distress call, suggest that they move towards a sibling in distress rather than fleeing and hiding. This behavior of sibling cooperation may enhance offspring survival if parents are more likely to respond and potentially discourage a predator. The behavior of sibling American crocodiles (Crocodylus acutus) in some situations seems like a paradox unless considered in the context of a cooperative strategy to escape predators.
|Université de Montréal, Canada
||#22 - Marie Barou-Dagues
||Inter-individual differences in female mate preference contribute in maintaining variability in male cognitive abilities in zebra finches (Taeniopygia guttata)
Growing evidence has demonstrated that females use male cognitive abilities as mate-choice criteria in several animal species. Yet, because most studies have focused only on few cognitive abilities that the males could demonstrate to females before they express their preference, they most often found an unanimous preference and as such, they cannot explain the maintenance of inter-individual differences in male cognitive abilities. In this study, we investigated whether differences among females in their body condition or cognitive abilities would be associated with differences in the importance they give to different male cognitive traits. Specifically, we measured the mating preference of 20 females that could chose among 4 males they had previously observed in a foraging context, as well as the body condition and the performances (subsequently summarized into two composite variables) of all individuals in 4 different cognitive tasks. We found that poor-condition females demonstrated a stronger preference for the first component (indicative of better male problem-solving and associative learning performances) whereas females with good cognitive abilities showed a stronger preference for the second component (indicative of lower male inhibitory control performances). Inter-individual differences among females in their needs and/or abilities to assess cognitively demanding traits could then contribute to maintaining individual differences in male and female cognition. Furthermore, our findings suggest that the strength of sexual selection on different cognitive traits should vary among populations and over time depending on local ecological conditions.
|PSL Research University, Paris
||#23 - Lara Narbona Sabaté
||Titi monkeys fine-tune their alarm message after urgent information is shared
Black-fronted titi monkeys (TCallicebus nigrifons) combine A- and B-calls into long alarm sequences. One previous study showed that the proportion of two successive B-calls (BB-grams) in the sequence conveyed reliable probabilistic information about predator’s type and location. However, this study only focussed on the first 10 calls of the sequence, used a limited number of features to describe the sequence, ignored that A- and B-calls can be suffixed, and did not investigate whether social factors influenced the sequences. In this study we investigated the effect of several contextual and societal factors on the structure of alarm sequences collected in experimental context. Specifically, we investigated whether encoded information varied between the first 10 and 50 calls by using a more fine-grained vocal repertoire, more refined sequence features borrowed from computational linguistics, and random forest algorithm for classification. We found that sequence structure (namely, the transition probabilities between different call types, the proportion of A-calls, and proportions of some tri, tetra, and pentagrams of B-calls and suffixed B-calls) was influenced by external factors. More importantly, predator type (i.e., aerial or terrestrial) was the only factor influencing the structure of the first 10 calls, but other factors influenced the late sequence (specifically, the distance from the predator, the predator species, and the number of unpaired adults and juvenile females in the monkey group). This suggests that, in alarm situations, titi monkeys first encode the type of predator and then refine the message incorporating other important contextual information and adapting their message to the audience. Our results also show that their alarm system relies on proportions and call combinations, which confirms that titi monkeys use a probabilistic coding system and suggest that they use syntactic structures to convey information. Further playbacks are needed to conclude on their communication capacities.
|University of Southampton, UK
||#24 - Helen Currie
||Application of Signal Detection Theory to understand the anti-predator responses of cyprinids to masked acoustic signals in still and flowing water
The negative impacts of anthropogenic noise on freshwater fish are becoming increasingly recognised. Detection of acoustic signals may elicit contextually dependent behavioural responses with respect to habitat selection, conspecific communication, social aggregations, or predator-prey interactions. However, high intensity background noise can disrupt the ability of a fish to extract important biological information from a local soundscape. While we are beginning to understand the influences of anthropogenic noise across some sensory modalities (e.g. distraction from visual or chemical cues), there remains little information on how the anti-predator responses of fish to acoustic stimuli are impacted by the masking effects of high intensity background noise. The ability to detect, discriminate and respond to biologically relevant sounds is influenced by the signal-to-noise ratio, components important to Signal Detection Theory which can provide a framework to better understand the effects of masking noise on fish response to environmental stimuli. Using high-resolution video tracking in combination with fine-scale environmental mapping, two complimentary laboratory studies were conducted to investigate how background masking noise impacts the behavioural responses of cyprinids to a pulsed tonal acoustic signal. This talk will discuss the potential ecological implications of masking anthropogenic noise, and how such knowledge may provide assistance in future acoustic deterrent system development to control invasive species, or manipulate fish behaviour at dangerous sites (e.g. dams, weirs, water extraction).
|Centre d'Ecologie Fonctionelle et Evolutive , France
||#25 - Mónica Arias
||Evolution of transparency diversity in butterfly and moth wings: transparency degree, size and position of transparent elements
Transparency is common in aquatic environments where it reduces detectability by predators. Transparency is rare on land and poorly studied. Recent studies have shown that Lepidoptera – a group in which transparency has independently evolved multiple times – displays a large variation in the degree, size and position of transparent zones. Such large diversity encompasses different types of clearwing species, including bee/wasp mimics and death leaf mimics. First, I will show comparisons between different observers, wild predators and artificial neural networks at detecting artificial butterflies with transparent wing patches of different sizes and positions. Our results confirm the efficiency of large transparent zones touching wing borders at reducing detectability. Second, I will show how the evolution of different transparency degrees could be related to habitat openness, and to mimicry syndrome, through two complementary approaches. First, by exposing artificial moth-like prey to wild avian predators in open and closed habitats, our fieldwork experiment shows an increase in prey survival at higher transparency degrees in open compared to closed habitats. Second, by analysing the evolution of wing characteristics and ecological traits in 107 clearwing species, comparative analyses show that instead, open habitat species show in average similar or slightly lower transparency degree than closed habitat species. We also find that bee/wasp mimics have highest and least varying transparency degrees and are more often diurnal. Compared to bees/wasp mimics, leaf mimics have lower but more varying transparency degree and are more often nocturnal. High transparency degree likely reduces detectability in open habitats, as shown by field experiments and comparative analyses of optical measurements on bee/wasp mimics. Our results suggest that detectability by predators, habitat openness, and species interactions play a crucial role in determining transparency design.
|University of Glasgow, UK
||#26 - Louise Riotte-Lambert
||Environmental predictability as a cause and consequence of animal movement
Environmental predictability is a critical determinant of animal movement. Animals that have the appropriate cognitive skills use it to reduce mortality risks and increase the efficiency of resource acquisition. Environmental predictability thus impacts individuals’ movement decisions, their fitness, and ultimately acts as a selective pressure upon cognitive skills such as spatial memory. In conjunction with the recent improvement of remote tracking technologies, the environmental predictability – animal movement interface has inspired a fast-growing albeit disparate literature. However, confusingly, studies do not use the same definitions of environmental predictability, nor the same analysis methods. In addition, the feedbacks of animal movement on environmental predictability have received very little attention, despite their presumed heavy impacts on many ecological processes, such as nutrient cycling or plant population dynamics. Overall, taking advantage of the current wealth of movement tracking and environmental remote sensing data to advance our understanding of the environmental predictability – animal movement interface urgently necessitates a synthesis of the current literature and the unification of concepts and methodologies. Here, I will present an integrative framework of the environmental predictability—animal movement interface. First, I will propose a general definition and detailed typology of environmental predictability for movement ecology, give examples of these environmental patterns, and briefly hint at the methodologies that can quantify them. Second, I will synthesize the movement patterns that emerge in response to environmental predictability, and the cognitive adaptations that mediate this emergence. Third, I will discuss how animal movement can impact environmental predictability, and how anthropogenic modifications of environmental predictability can impact the movement of other animals, a major threat to wildlife species that is still very poorly understood. Finally, I will conclude by highlighting the current research challenges for the study of the feedback loop between environmental predictability and animal movement.
|National Centre for Biological Sciences, India
||#27 - Dinesh Natesan
||Foraging for food: How fruit flies locate an odor source in complex visual and airflow environments
In nature, flying insects searching for food (or a mate) must follow plumes of odor through visually cluttered environments. Localizing the odor source requires the use of both visual and olfactory modalities in varied airflow conditions. Here, we investigated the role of small-field visual landmarks in odor localization of freely flying fruit flies (Drosophila melanogaster) in two different airflow conditions - a laminar airflow which generated plumes of odor and still-air where the odor was dissipated by diffusion. In both cases, we paired odor with different combinations of low- and high-contrast visual landmarks to decouple the effect of visual cues. Analyzing the trajectories of flies localizing odor revealed several novel features. First, odor increased the flies’ salience towards visual objects; flies approached and hovered in the vicinity of visual landmarks in the presence of odor in both airflow conditions. In addition, the increased salience towards visual objects persisted for several seconds after an odor encounter, suggesting a change in the fly’s state. Second, localization of odor relied on co-occurrence of visual and olfactory cues in both moving and still-air; ambiguities in co-occurrence induced by separating vision and odor induced errors. These errors were distance-dependent; the erroneous landing rate decreased as the visual landmark was moved farther from the odor source. Third, odor-localization strategies adopted by flies were different in moving and still-air. In airflow, flies fly crosswind, meandering in and out of the odor plume, abruptly slowing down on odor-encounter. In contrast, their movements are faster and saccadic in still-air. These strategies are robust and share distinct similarities in the multimodal aspects of the behavior. Hence, odor localization in flies emerges as a result of complex interactions between multiple sensory modalities, enabling the fly to reliably forage in diverse visual and airflow environments.
|Instituto de Investigaciones Biológicas Clemente Estable, Uruguay
||#28 - Nadia Kacevas
||Aerial dispersion in web wolf spiders: is the South American Aglaoctenus lagotis capable of fly?
Spiders have developed a particular type of dispersion known as ‘ballooning’. By releasing silk threads that are blown by the wind, spiderlings can travel short or long distances. Aglaoctenus lagotis is a South American wolf spider that lives on funnel-webs, differing from the wandering habit that characterizes the members of the family. The southern form of this species inhabits the herbaceous stratum of grasslands and hills of Uruguay. Given this strong habitat specificity and the high proportion of offspring that remains around maternal webs, we tested here if A. lagotis spiderlings are capable of dispersing by the air. Experiments were performed under laboratory and field conditions, during day and night, and using Schizocosa malitiosa spiderlings as a positive control. Once the offspring descended from their mothers, they were exposed to an upward air current that did not exceed 3 m/s. We registered pre-ballooning behaviors (drop on a dragline and tip-toe) by direct observation for 15 minutes or until spiderlings performed ballooning. In the laboratory, ballooning was registered in the 13% of A. lagotis trials and in the 24% of S. malitiosa trials, while in the field ballooning was registered in the 40% of A. lagotis trials and in the 37% of S. malitiosa. This behavior was most frequent during the day for both species, in fact A. lagotis never performed ballooning in nocturnal trials in the field. Tip-toe, considered an unequivocal behavior that precedes ballooning, was never performed by A. lagotis spiderlings, neither in the laboratory nor in the field. Drop on a dragline was more frequently performed by A. lagotis than S. malitiosa (X2=51.49, P<1x10-5 in the laboratory; X2=44.12, P<1x10-5 in the field). We discuss the characteristics of the aerial dispersion registered in A. lagotis considering that it is a funnel-web spider in a family with wandering habit members.
|University of São Paulo, Brazil
||#29 - Hilário Lima
||Cache behavior in army ant species Eciton hamatum (Formicidae: Dorylinae)
The cache is a point where some animals pile-up of food. Caches can be founded in foraging trails of some species of ants like leaf-cutter ants and can occur at points where obstacles on the trail, causing workers to stop for a while and accidentally dropping leaves, which accumulate and form the cache. In army ants, the cache behavior never was studied. Our research was carried in a fragment of the Amazonian primary rainforest in Bragança, Brazil (-1.036958, -46.764066). Our goal was to perform the first characterization of cache behavior for an army ant species. Eleven caches of E. hamatum (1) had the environments described, (2) the caches were recorded in a video for 5 minutes to measure the flow of workers carrying one prey, multiples prey or without preys and (3) six caches were collected and prey was identified and measure. Most caches occurred in areas where obstacles can increasing the number of workers on the trail. A small part of the worker's carrying one prey stop in the cache, and other, carrying multiples preys or without prey follow a normal flow. We found 697 prey of ants species in caches (Formicinae, Dolichoderinae, and Myrmicinae), ranged from 0.5 mm to 5.5 mm, however, only 5 prey was larger than 4 mm. Move on the Amazon rainforest soil can be costly because has a lot of debris. E. burchellii builds bridges over obstacles using the worker’s bodies, facilitating the flow of workers along the trail, however, E. hamatum did not show this behavior, can deal with obstacles using caches, where only a small part of the workers who carry smaller prey stop at the caches, while those who carry more prey at once or larger prey can go straight to the bivouac, keeping the flux of worker constant.
|IMBIV Universidad Nacional de Córdoba, Argentina
||#30 - María Eugenia Drewniak
||Color preference flexibility of butterflies in two co-occurring mock verbains under different pollination contexts
Pollinators' feeding behavior has direct consequences for plant reproduction and can mediate the evolution of floral traits such as corolla color. Some pollinators show strong innate color preferences, but many others show flexibility in their preferences due to learning associations between corolla color and rewards and/or variable color perception. Besides, some pollinators exhibit strong floral constancy restricting their flower visits to a single plant species, avoiding alternative rewarding flowers present in the community. Thus, studying the dynamics of pollinators´ behavior under natural field conditions is important to understand how plant-pollinator interactions occur. We studied two co-occurring Glandularia species (Fam. Verbenaceae) from southern South America that differ in corolla color (red vs purple) which are mostly pollinated by diurnal butterflies. We recorded the visitation rate of the pollinator assemblage in these two mock verbains species and in a less abundant pink-flowered natural hybrid under two different pollination contexts (natural community vs. controlled experimental plots). First, we analyzed the interaction between the mock verbains and their pollinator assemblage using an interaction network approach under a null expectation of random visitation. We recorded a pollinator assemblage of 15 butterfly species from three families (Papilionidae, Nymphalidae and Hesperiidae) that showed visitation rates higher, lower or no different from a random expectation taking into account species abundances. Observed trends were mostly congruent between pollination contexts. Second, we evaluated the floral constancy (i.e. when transition between consecutive visits were to the same flower color) of butterfly species by recording individual visitation sequence in the experimental plots. In general, most species showed a strong to moderate constancy, with five species being mainly constant to red, six species to purple and four species to pink. Interestingly, none butterfly species visited the pink-flowered hybrid in the natural community. The possible causes of our findings are discussed.
|Indian Institute of Science Education and Research, Kolkata, India
||#31 - Rohan Sarkar
||Scavenging Strategies in Free-ranging dogs
Domestic dogs have descended from gray wolves through a process of domestication, evolving from a predominantly hunting to a scavenging lifestyle. Various behavioral adaptations in dogs are considered to have been crucial to the development of the unique bond shared by dogs and humans. Similarly, an enhanced ability to digest carbohydrates has been suggested as a major adaptation that enabled dogs to adapt to life among humans. Free-ranging dogs in India mostly subsist on a carbohydrate-rich diet. They usually live in groups but they tend to forage solitarily, though sometimes humans provide food to them. In a “Cafeteria Choice Test”- like condition, they use a Rule of Thumb (ROT) to locate meat, even when scavenging, thereby maximizing meat uptake from the noisy background of garbage. We carried out the test on 68 free-ranging dogs on urban streets, simulating scavenging from dustbins, to test whether they use the ROT in scavenging situations and found that they implemented the ROT through a Sniff-and-Snatch strategy for maximizing meat uptake first, but they did not discard the carbohydrate either. They often compete with conspecifics, other scavenging species and are sometimes threatened by humans during scavenging. Under such constraints, this is a highly efficient scavenging strategy that can help them to maximize food intake, while allowing them to eat the most preferred food first, and has perhaps been adaptive for their survival in a highly heterogenous human-dominated environment. This work provides evidence towards the dogs having developed an evolutionarily stable strategy of feeding.
|University of York, UK
||#32 - Elva Robinson
||Dynamic ant networks: how does a changing resource environment shape social structure?
Animal social structure is shaped by environmental conditions, such as food availability; this means that changing conditions can alter social structures and result in cascading ecological effects. Understanding both how the resource environment causes certain social structures to arise, and also how resilient such structures are in the face of environmental change, is essential to understand the relationship between animal societies and their ecological context. Wood ants are an ideal study system for this, because they depend on discrete identifiable food resources (trees), and form large networks enabling resource sharing between socially connected nests of the same colony. We have collected data on the social network dynamics of 13 large multi-nest colonies of the wood ant Formica lugubris over 7 years, and manipulated resources to test social resilience. Our dynamic network analysis results show that nest survival is affected by social position; specifically, the flow of resources through a nest, a result of its position within the wider network, determines a nest's likelihood of surviving. Combined with size-based nest foundation, this enables the network as a whole to track the resource environment, resulting in a network structure that is well-matched to the spatial pattern of resources. Using manipulations to prevent access to certain key resources, we show that losing an important food source causes colony networks to split into smaller components, but without reducing growth or survival. Taken together, these results show a dynamic social structure that responds flexibly to both gradual and abrupt changes in the resource environment.
|Sabancı University, Turkey
||#33 - Tuğçe Rükün
||Sub-lethal pesticide exposure skews color vision perception in foraging honey bees
Honey bee health is in global decline and yet bees play an integral role in our current agricultural production of food. Neonicotinoid pesticides continue to be used around the world despite being demonstrated that they have detrimental sub-lethal effects. The neonicotinoid, imidacloprid, works by disrupting the acetylcholine activity of the central nervous system and could therefore potentially affect color vision perception as the visual neuropils rely on cholinergic signal transmission for proper functioning. Therefore, we investigated if imidacloprid is responsible for skewing color perception of foraging honey bees by assessing their color preferences after being exposed with a range of sub-lethal levels of imidacloprid (4-40% of the LD50 value). We found that there is a significant shift in preference for flowers with a relatively higher frequency and shorter wavelengths, as the pesticide dose increases, with a threshold response of around 20% of the LD50 value. Based on previous literature we hypothesize that the cause of this shift is due to the disruption of the color vision opsins in the bee brain. We are currently measuring the gene expression of opsins and rhodopsin in the bee brain to confirm this and to gain more insights of the mechanism responsible for this shift in color flower preference. A potential shift in color vision perception will lead to lower flower fidelity and this would consequently lower the foraging efficiency and fitness of the honey bee colony. Furthermore, lower flower fidelity of bee colonies transported to agricultural crops for their pollination services would also result in lower pollination efficiency of particular monoculture crops. Moreover, the behavioral effects shown here are in addition to the already known existing detrimental sub-lethal physiological effects of imidacloprid exposure and may be partly responsible for honey bee colonies collapsing around the world.
|Federal University of ABC, Brazil
||#34 - Michaella Andrade
||On a phylogenetic perspective of the evolution of animal sentience: going back to the origin of Metazoa
Current evidence indicates that the mechanisms of response to noxious stimuli and sentience may have been preserved during animal evolution. Because this area of research still has a vertebrate-centric bias, we tried to fill the recognizable gap of knowledge regarding non-vertebrate animals through a phylogenetic perspective, testing the hypothesis of common ancestry of characters related to sentience. We used general morphological, nervous and sensory system characters, as well as genetic markers of pain and nociception and also behavior characters, to perform phylogenetic analyses under different optimization methods. We have a taxonomic sample of 26 supra-specific taxa of Metazoa. In the phylogenetic hypotheses resultant from our analyses, the main clades of animals were recovered as monophyletic groups, with Porifera as a sister-group to the other Metazoa. Based on morphological and molecular traits, we found evidence of the appearance of a certain degree of sentience since the common ancestor of Eumetazoa, with a strong diversification beginning in Urbilateria. Behavior features such as classical, operant conditioning and responses to several noxious stimuli were widely distributed, but there is a considerable gap for some lineages of Protostomes. Our research is the first attempt to reconstruct the evolutionary pattern of the sentience based on different categories of characters, and has allowed us to explore an interesting scenario where morphological traits of the sensory system have appeared even before the appearance of nerve cells. Such traits may have been co-opted during the evolution of the nervous system and sensory modules of Eumetazoa. The attributes here analyzed indicate that a biochemical, physiological and behavioral basis preceded the appearance of the centralized nervous system, suggesting a gradual perspective to the evolution of sentience since the origin of bilateral animals.
|University of Tehran, Iran
||#35 - Sajedeh Sarlak
||Bumblebees learn to avoid noxious stimuli and remember it for a long time
In order to increase their fitness, animals must be able to interact continuously and effectively with their complex environment. When exposed to damaging stimuli, most insects change their behaviour which is essential to an animal’s survival. Behavioural change from norm and avoidance learning in company with a prolonged memory indicates that the animal has sufficient cognitive abilities and the ability to use complex information which implies central processing rather than an immediate reflex response. In this study we tested the avoidance behaviour of bumblebees, Bombus terrestris, in response to electric shock and then recorded the memory of bees for about two weeks to investigate their memory performance in recalling a noxious stimulus. Insects exposed to shock stimulus learned to associate the shock with the colour cue, also 14 days after training, bees could still identify the noxious stimulus, which may reduce damage over a relatively long time. These results are consistent with the view that insects can remember a noxious potentially painful stimuli for approximately a long time. The capacity to learn and remember about aversive outcomes of dangerous situations can enable insects to overcome adverse consequences and have more appropriate choices in similar situations.
|Indian Institute of Science Education and Research, Kolkata, India
||#36 - Ishani Mukherjee
||Shoals under threat: immediate response of wild zebrafish shoals to predatory cues
Shoaling in fishes is regulated by a variety of factors like predation, vegetation cover, water flow and food availability. In our current study, we focus on one such factor- i.e., predation and we ask how shoaling in wild zebrafish (Danio rerio) is impacted by cues from its natural predator, the snakehead Channa sp. Following thirty-minute acclimatization, zebrafish shoals comprising ten fishes were recorded for twenty minutes exposed to a predator cue (visual or olfactory) or both cues together. In control experiments, shoals received no predator cue. We found some interesting results on analyzing group level properties in 60 shoals. Generalized linear mixed models followed by post hoc tests suggested the largest subgroup was significantly larger among shoals exposed to predator cue (compared to controls). Also, there was no significant change in largest subgroup size over twenty minutes across the four treatments. We performed a detailed characterization of shoals’ first five minutes of exposure to predator cues (the immediate response). We found that: (1) Interactions (group leader-follower interactions and contacts) and individual associations (observed by constructing networks) significantly increased in presence of a predator cue. (2) Shoal cohesion, depicted in heatmaps, increased significantly in presence of any of the cues. (3) A positive correlation existed between shoal centroid speed and polarization across all treatments. (4) Lastly, polarization was significantly greater in shoals receiving a predator cue, suggesting shift from more shoaling to more schooling in presence of a predator cue. Zebrafish relied equally on visual and olfactory cues (of a given concentration) to escape predation. We speculate that continued responses over several generations in high predation pressure populations have led to evolution of tighter shoal formations. While this work provides insights on how predation alters shoaling, further investigations are needed to understand the underlying physiological and biochemical mechanisms driving shoal dynamics.
|Pontifical Catholic University of Rio Grande do Sul, Brazil
||#37 - Kanandra Bertoncello
||Tebuconazole alters behavioral and neurochemical parameters in larvae and adult zebrafish (Danio rerio)
Tebuconazole is a fungicide characterized by its high toxicity that causes adverse effects to non-target organisms. These agents pose a threat to the ecosystem due to contamination that occurs with the increase of agricultural maintenance. Pesticides in aquatic ecosystems may be transferred through phytoplankton to fish and finally to humans. In this study, we evaluated the effects of tebuconazole on exploratory larvae behavior and adult locomotion, and the effects of this fungicide on acetylcholinesterase activity in zebrafish larvae and adult zebrafish brain. For larvae treatment, embryos were exposed to tebuconazole treatment at concentrations of 1, 2, and 4 mg/L for 120h (1h post-fertilization to 5 days post-fertilization). Adult treatments occurred in a 2L aquarium (8 animals per tank) and exposed to tebuconazole at concentrations of 1, 4, and 6 mg/L for 96h. Two control groups were utilized, one in which the animals were exposed only to water and another that contained the vehicle (0.1% DMSO). The exploratory behavior of the larvae was evaluated at 5 days post-fertilization and adult locomotion was evaluated after 96h of treatment. Tebuconazole (4 mg/L) reduced the distance traveled, absolute turn angle, line crossing, and time outside area in exposed larvae. Moreover, adult zebrafish that were exposed to this fungicide (4 and 6 mg/L) showed a decrease in distance traveled and mean speed when compared to the control group. However, tebuconazole did not alter the number of line crossings or time spent in the upper zone. Tebuconazole inhibited acetylcholinesterase activity at concentrations of 4 mg/L for larvae and 4 and 6 mg/L in the adult zebrafish brain. These findings demonstrated that tebuconazole could modulate the cholinergic system by altering acetylcholinesterase activity and that this change may be associated with the reduced locomotion of these animals.
|Indian Institute of Science Education and Research, Kolkata, India
||#38 - Prothama Manna
||Response to barking playback in free-ranging dog groups
Canids display a vast diversity of the social organization, from solitary-living to pairs to packs. Domestic dogs have descended from pack-living grey wolf-like ancestors. Unlike their group living ancestors, free-ranging dogs are facultatively social, preferring to forage solitarily. They are scavengers by nature, mostly dependent on human garbage and generosity for their sustenance. Free-ranging dogs are highly territorial, often defending their territories using vocalizations. Vocal communication plays a critical role in inter and intra-group communication, influencing the social dynamics of the dogs. Barking is the most common of the different types of vocalizations of dogs. Dogs have a broad hearing range and can respond to sounds over long distances. Domestic dogs have been shown to have the ability to distinguish between barking in different contexts. Since free-ranging dogs regularly engage in various kinds of interactions with each other, it is interesting to know whether they are capable of distinguishing between vocalizations of their own and other groups. In this study, a playback experiment was used to test if dogs can differentiate between barkings of their own vs other groups. Though dogs respond to barking from other groups in territorial exchanges, they did not respond differently to the self and other group barks in the playback experiments. The barking tracks were also indistinguishable analytically. This suggests a role of context in the interactions between dogs and opens up possibilities for future studies on the comparison of the responses of dogs in playback experiments with their natural behaviour through long-term observations.
|Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Argentina
||#39 - Camila Dávila
||Differential behavior of a specialist willow herbivore in wild and domesticated hosts
Plant domestication has resulted in the modification of specific plant traits to increase yield and quality for human consumption. However, selective breeding has frequently led to a reduction of chemical defenses, usually affecting parameters of herbivores behavior. As a result, domesticated plants are generally more susceptible to damage by herbivore insects compared to their wild relatives. In Argentina, willow plantations (Salix spp) are important in forest production. The willow sawfly, Nematus oligospilus is a specialist pest of Salix species. Recently we showed that previous conspecific herbivory on Salix humboldtiana, a native willow from South America, decreased oviposition preference, larval performance and survival of N. oligospilus. This suggests an induced response of the plant to insect damage that can increase its resistance. Here we compared N.oligospilus behavior in two different willow genotypes: wild willow S. humboldtiana and the high domesticated, frequently cultivated for paper fiber S. babylonica (var. Sacramenta). First we studied oviposition preference of N. oligospilus by offering, in dual choices, the two genotypes either undamaged or after egg laying and larval feeding. We also compared the performance of newborn larvae that initiated their development on both willow species on which they hatched from eggs. Our results showed a marked preference for laying eggs on native S. humboldtiana regardless prior insect damage. When comparing the larval performance on wild and domesticated willows, larval development time was shorter, and larval and pupal weight higher on S. humboldtiana. Our results suggest a higher resistance in domesticated S. babylonica to female oviposition and larval feeding of this specialist insect. This differential behavior may be due to a higher constitutive defense levels or lower nutritional values in domesticated willow compared to the wild genotype.
|Oberlin College, USA
||#40 - Franne Kamhi
||View based navigation in ants requires the mushroom body vertical lobes
Successful navigation is crucial for finding mates, foraging, defending territories, and avoiding predators. Visual landmarks can provide reliable information about an animal’s location in space and the direction to a goal. Even with miniaturized brains, ants are exceptionally accurate at visually navigating and pinpointing locations of interest. Ants have been shown to perform learning walks to acquire landmark information prior to beginning to forage. Experienced foragers are thought to match memorized views to their current views to successfully return home. We aimed to determine the brain region involved in this view-based navigation in the Australian bull ant, Myrmecia. These ants are visually oriented, and foragers primarily use terrestrial landmarks for finding their way home from their nest-specific foraging trees. In Myrmecia midas foragers that were motivated to return home, we injected the anaesthetic procaine into the mushroom body vertical lobes, a region implicated in long-term memory formation. We compared these ants’ ability to return home to that of untreated controls, saline-injected controls, and off-target controls. I will discuss how the mushroom body vertical lobe is necessary for retrieving visual memories for successful view-based navigation in a natural foraging environment.
|University of Toronto, Canada
||#41 - Amanda Facciol
||Embryonic ethanol-induced social deficits in adult zebrafish are differentially altered depending upon the developmental stage of exposure
In humans, Fetal Alcohol Spectrum Disorder (FASD), which arises when a developing fetus is exposed to alcohol, is characterized by a number of morphological, behavioural and cognitive deficits. FASD is a highly variable disorder, and deficits can range from mild to severe despite similar drinking patterns in mothers. To better understand this disorder, these deficits have been studied in animal models, most commonly in rodents. However, the zebrafish is gaining popularity in the field of FASD research due to their external fertilization, non-invasive alcohol administration techniques and transparent embryos. In zebrafish, embryonic ethanol induced deficits in a number of behaviours have been successfully modeled, including social behaviour, learning and anxiety. Interestingly, behaviours have been shown to be differentially altered depending upon the stage of embryonic alcohol exposure. For example, learning has been shown to be altered with a short, low ethanol dose administered at 16 hours post fertilization (hpf), whereas social behaviour is altered with the same exposure regime at 24hpf. However, systematic analysis of developmental stage dependency of ethanol exposure induced changes in social behaviour has not been performed. Here, we expose zebrafish to low doses of ethanol (1% vol/vol) for a short 2 hour period at five stages during embryonic development (5hpf, 10hpf, 16hpf, 24hpf, 36hpf). Following this exposure, zebrafish were raised normally and tested in a social paradigm in adulthood. Our results suggest that developmental stages between 10hpf and 24hpf may be particularly sensitive to the teratogenic effects of ethanol. Adult zebrafish exposed to ethanol during these developmental stages do not respond normally to the social stimulus, whereas zebrafish exposed earlier (5hpf) or later (36hpf) in development exhibit a normal social response. This experiment marks one of the first to investigate how short, low ethanol doses differentially alters adult social behaviour in a developmental stage dependent manner.
|University of Cambridge, UK
||#42 - Alizée Vernouillet
||Thick as thieves? Highly social pinyon jays (Gymnorhinus cyanocephalus) do not discriminate between thieves and bystanders when storing food
Previous studies on avian cognition have focused on the birds’ amazing abilities to discriminate between objects, numbers, or even concepts. However, social discrimination in birds remain relatively unexplored. Here, we examined whether a highly social corvid species can discriminate individuals in a food-storing (caching) context. Caching species rely on food caches to survive when resources are scarce. These caches may be pilfered by observing birds present at the time of caching. To reduce the risk of losing their caches to others, cachers can modify their caching behaviour when perceiving a pilfering threat. In particular, we evaluated whether cachers could discriminate between potential thieves and non-pilfering individuals, and modifying their caching behaviour accordingly. Pinyon jays cached pine nuts in two visually distinctive trays under four conditions: Alone, observed by a Non-Pilfering Conspecific, observed by a Pilfering Conspecific, and by an Inanimate Heterospecific (a taxidermy bird). After caching, one tray (pilfered tray) was put in the adjacent cage compartment, and caches were removed from it during the Pilfering Conspecific and the Inanimate Heterospecific conditions, but not during the Alone and the Non-Pilfering conditions. The other tray (safe tray) was put in a visible location out of reach from both birds. Overall, pinyon jays reduced the amount of pine nuts cached in the pilfered tray when observed compared to when they cached alone. However, birds did not discriminate between the Non-Pilfering and Pilfering Conspecifics. Thus, we found that pinyon jays modify their behaviour to reduce the pilfering risk when observed, but do not discriminate between individuals when assessing the pilfering risk.
|Federal University of ABC, Brazil
||#43 - Kátia Selene de Melo
||On the use of responses and stimuli to time intervals
Human and non-human animals are usually very good at estimating the duration of events (referred to as “interval timing”). The start of the event is often called the “time marker”, that is, the point from which one must start timing. Time markers can be self-controlled (e.g., a response emitted by the organism) or can be external to the organism (e.g., stimuli from the environment, as a light or sound). But do they lead to similar temporal performance (i.e., is the organism as precise and accurate in timing an interval when a response or a stimulus is a time marker)? Although some studies have suggested similar temporal performance for intervals initiated by certain responses or stimuli, the effect of the different types of time markers on temporal performance is still poorly described. Here, we investigated whether a light and a lever press lead to similar temporal performance when used as time markers. One group of rats was trained to sustain a lever press (Group Response, R) for at least 1.5 s (Experiment I) or 3.0 s (Experiment II) in order to receive a sugar pellet. For another group the same contingency applied, but a light stimulus turned on while the lever was pressed (Group Stimulus+Response, SR). After rats learned to correctly sustain their lever presses to get the pellets, catch trials were inserted (20% of total trials). For Group R, in catch trials the light was turned on during lever presses (similar to Group SR). For Group SR, in catch trials the light was off during lever presses (similar to Group R). Results showed that for Group R, the new light did not affect performance. However, for Group SR, when the light was removed response durations increased, suggesting that the light was an important - although not exclusive - time marker.
|University of Buenos Aires, Argentina
||#44 - Rocío Lajad
||Pollen learning in young honeybees: consumption preferences mediated by experience
Pollen nutritional content differs between plant species. Then, honeybee Apis mellifera may select pollen and adjust their intake to meet the nutritional requirements of its colony. The mechanisms by which honeybees evaluate and select pollen is little understood. Because pollen is mainly consumed at early ages, we hypothesized that pollen evaluation is mediated by young workers, who adjust pollen consumption after they experienced the different pollen types that are being processed inside the nest. Therefore, we investigated the ability of young bees to evaluate and learn pollen types according to their quality (i.e. digestibility and/or palatability). To this aim, we fed the bees (either young workers confined in cages or nurse bees inside honeybee hives) two pollens (A+B) and compared their consumption preferences two days after they had the chance to experience one of the two pollens adulterated. Pollen quality was reduced by adding deterrent substances (quinine and amygdalin) or improved by a phagostimulant (linoleic acid). Consumption preferences were tested using unadulterated pollen. Controls where pollens were not adulterated were also included. In both caged-bees and hive-bees, consumption of pollens that had been adulterated with quinine was significantly reduced compared to the control. Despite the increase in the consumption of pollen that had been adulterated with linoleic acid, no differences were found respect to control group, yet it was significantly higher than that of the group amygdalin and quinine. These results show that young bees are able to associate specie-specific pollen cues with distasteful and/or malaise experience, leading to aversive memories that modulate the consumption preferences.
|Instituto de Investigaciones Forestales y Agropecuarias Bariloche, Argentina
||#45 - Andres Martinez
||Kinship and density in Vespula germanica (Hymenoptera: Vespidae) drone aggregations
In social insects, whose reproductive individuals generally leave the nest for copulation, mechanisms deployed to minimize inbreeding, such as dispersal and avoidance of relatives, are important for the success of the population. At the time of leaving the nest, the density of related individuals is high, thus favoring inbreeding and, given their sexual determination system (single-locus complementary sex determination), the number of infertile triploid males increases. Vespula germanica is an eusocial and polyandry wasp that has successfully established in different parts of the world, including the Patagonia Argentina. In this study, we ask whether male wasps display specific aggregation behavior that promotes genetic diversity. High levels of genetic diversity in male aggregations could be important to reduce inbreeding, because the high numbers of individuals in aggregations could decrease the probabilities of mating with relatives. Our aim was to establish under laboratory conditions, the effects of relatedness and density in encounters between drones. Based on the assumption that due to the negative effects of inbreeding in hymenopterans, V. germanica drones will promote genetically-diverse aggregations, we expected to find a lower avoidance threshold (i.e. a lower number of drones) toward kin than that toward non-kin. Using a 4-way olfactometer, we evaluated the behavior of drones towards different densities of individuals (2, 6 and 10 drones), related and unrelated. We show that drones avoid aggregating with their nestmates at all densities while non-nestmates are avoided only at high densities. This suggests that genetic diversity and density in V. germanica drone aggregations could be regulated through drone behavior and in the long run minimize inbreeding, thus favoring invasion success. A better understanding of the mechanisms involved in the reproductive process of V. germanica drones, could be important to integrate it into the management programs of this problematic species.
|Queen Mary University of London, UK
||#46 - Joanna Brebner
||Strategic Line Following by Freely Flying Bumblebees
Line and road following behaviour, or the extended use of ground-level linear features, in non-human animals has been described in seasonal migrators, in pigeons and most recently in honeybees. Linear features, naturally occurring and of human origin, have been shown to change species dispersals, their population spread and their navigation behaviour. In navigation, following linear features has been suggested as a cognitively inexpensive alternative to learning routes, with the disadvantage of increasing the risk of errors such as aliasing, where two similar structures are mistaken for one another. For pollinators, line use is interesting in regards to intensive agriculture, where the borders of fields present very strong linear features in an otherwise visually sparse landscape. To explore the extent to which pollinators use lines in navigating agricultural environments, we used harmonic radar to track the flights of commercially-obtained bumblebees (Bombus terrestris) in an open featureless landscape of fields with prominent ground-level paths. Individuals were tracked during their first exploratory flights, flights to artificial feeders and flights to distant natural forage. We demonstrate that bees followed linear features in their first flights, during flights to known foraging locations, and when searching for a removed experimental feeder. We also found that a feeder along a path was discovered quicker and used more frequently than one 100m from a path. Our data shows evidence of aliasing, where bees search for the nest after following parallel roads. Finally, we discuss whether bumblebee line following behaviour is part of a navigational strategy or the effect of bee flight mechanisms.
|University of California, Los Angeles, USA
||#47 - Amanda Klingler
||Environmental Context Influences the Consequences of Exploratory Personality
Exploratory personality, the propensity of an individual to actively explore novel environments, has been linked to improved competitive ability under stable environmental conditions. However, it is unclear how exploratory personality may influence fitness under variable environmental conditions. To understand how changing environmental contexts influence the benefits gained from an exploratory personality, we used a desert-dwelling ectothermic jumping spider (Habronattus pugillis Griswold), that regularly experiences environmental fluctuation as a model organism. Using an assay to quantify exploratory behavior, combined with prey capture assays performed at three biologically relevant temperatures, we examined the interaction of exploratory behavior and temperature on individuals’ prey capture behavior. We found that independent of exploratory personality; individuals were more successful at capturing prey at hotter temperatures. However, we did observe an interaction of temperature and exploratory personality on the latency to capture prey and the initial recognition of prey, such that more exploratory individuals are slower to recognize and capture prey at lower temperatures.
|University of Cincinnati, USA
||#48 - Annemarie van der Marel
||A framework to evaluate whether to pool or separate behaviors in a multilayer network
A multilayer network approach combines different network layers, which are connected by interlayer edges, to create a single mathematical object. These networks can contain a variety of information types and represent different aspects of a system. However, the process for selecting which information to include is not always straightforward. Using data on two agonistic behaviors in a captive population of monk parakeets (Myiopsitta monachus), we developed a framework for investigating how pooling or splitting behaviors at the scale of dyadic relationships (between two individuals) affects group-level social properties. We designed two reference models to test whether randomizing the number of interactions across behavior types results in similar structural patterns as the observed data. Although the behaviors were correlated, the sociality measures derived from observed data fell outside the distribution of those derived from the reference model. However, once we controlled for data sparsity in our second reference model, we found that measures from the observed data then fell within the range of those from the reference model which showed that this result may have been due to the unequal frequencies of each observed behavior. Thus, our findings support pooling the two behaviors. This framework can be used for any type of behavior and question, however, caution should be used when interpreting the results as some measures are sensitive to data properties, such as unequal rates of observed behavior in our case. This framework will help researchers make informed and data-driven decisions about which behaviors to pool or separate, prior to using the data in subsequent multilayer network analyses.
|University of Buenos Aires, Argentina
||#49 - Bruno E. Rosso
||Entomopathogen infection alters feeding behavior in the southern green stinkbug, Nezara viridula.
Nezara viridula is a major pest of soybean crop with important economic losses. The stinkbug can tolerate soybean plant defenses as protease inhibitors and isoflavonoids. While gut bacteria can help some insects to overcome plant defenses, some plant allelochemicals may help insects to overcome entomopathogen infection. Although most of adults of N. viridula collected from soybean crops are free of cultivable bacteria, around 30% of the population have quite simple gut bacterial community, with less than 8 species. Moreover, the entomopathogen Serratia marcescens has been found in the gut of some individuals. We proposed that gut bacteria affect feeding behavior of N. viridula, modifying plant species preference of feeding. On summer, N. viridula adults can be found feeding on crops of soybean or corn, or on another weeds, as the glyphosate resistant Amaranthus quitensis. To evaluate the effects of entomopathogen infection on insect feeding behavior, we performed a 7-day multiple-choice field experiment where 20 non-infected and 20 Serratia sp. lab-infected stinkbug adults were challenged to feed on soybean or secondary hosts (corn, A.quitensis or spontaneous grown weeds), inside 3x3 mt gazebo (n=4). We found interactions between Serratia sp. infection and N. viridula host preference (p=0.001). While Serratia sp. infected stinkbugs preferred to feed on soybean, non-infected stinkbugs preferred feeding on secondary hosts. Moreover, Serratia sp. infected stinkbugs were seen switching hosts, while non infected-stinkbugs remained in their first choice of host. Here we demonstrate that entomopathogen infection changes feeding behavior of Nezara viridula adults, maybe due to the necessity to eliminate the bacteria through ingestion of antimicrobial compounds or changes in C/N ingestion, as a self-medication behavior.
|Federal University of ABC, Brazil
||#50 - Estela Braga Nepomoceno
||Involvement of the Insular and Prefrontal Cortex during a temporal decision making in rats
The anterior portion of the insular cortex (AIC) comprises a region of sensory integration that appears to detect salient events to guide goal-directed behavior, code error awareness, and estimate the passage of time. Projections between the AIC and medial prefrontal cortex (mPFC) - observed both in rats and humans - suggest a function of these structures in the integration of autonomic responses in ongoing behavior. Although studies have tried to describe the role of those structures in decision making and time estimation tasks, their findings are not consistent, and a possible causal relationship between those areas remains unclear. This study aims to explore the role of the AIC and mPFC in temporal decision-making in rats during a switch paradigm. In this task, the simultaneous presentation of two lever options that predict reinforcement after a fixed interval (short 3 s or long 6 s) leads to the emergence of a switch behavior. The switch behavior corresponds to the moment in a trial in which the rat stops to try the short option and goes to the long one in search of a reward. After training, eighteen male Wistar rats received bilateral microinjections of muscimol (a GABA-A agonist) or vehicle into mPFC or AIC before the switch task. Results showed that the rats switched levers to maximize their expected gains in vehicle sessions. The mPFC inactivation revealed a change in the switch latency distribution, impairing interval timing accuracy and precision. The AIC inactivation revealed a change only in the timing precision. Our results contribute to the understanding of the neural mechanisms underlying the encoding of uncertainty as a function of time.
|Pontifical Catholic University of Rio Grande do Sul, Brazil
||#51 - Melissa Talita Wiprich
||Zebrafish model of huntington’s disease: effects of 3-nitropropionic acid on locomotor activity in larvae and adult animals
Huntington’s disease (HD) is a hereditary neurodegenerative disorder characterized by motor dysfunction, neuropsychiatric disturbance, and cognitive decline. The neuropathological features are striatal neurodenegeneration, and decreased mitochondrial activity of complex II-III. One of the models of HD is induced by a mitochondrial toxin, the 3-nitropropionic acid (3-NPA), which has been used in murine and primates. 3-NPA is a mitochondrial complex II irreversible inhibitor able to reproduce phenotypic features of the HD. Here we investigated the effect of 3-NPA administration on locomotor activity in larvae and adult zebrafish. Larvae zebrafish were treated for 7 days of 3-NPA at concentrations 0.01, 0.05, 0.1, 0.2 and 0.5 mM (n=20). The locomotor activity analysis was performed at 7, 10, and 14 days. Adult animals received 7 intraperitoneal injections of 3-NPA at doses 10, 20, and 60 mg/kg over the 28 days. The locomotor activity analysis was performed 24 hours after each injection and 120 hours after the last injection (n=20). The parameters tested were traveled distance, velocity, and absolute turn angle. Also were evaluated the time spent in the outside area for larvae and time spent in the upper zone for adults. There were no differences in all parameters analyzed at any age of larvae zebrafish treatment. However, in adult animals all doses of 3-NPA treatment decreased the traveled distance (p<0.001). There was a decrease in the absolute turn angle at doses 20 and 60 mg/kg. In contrast, there were no changes in the time spent in the upper zone in 3-NPA-treated groups. These findings indicate that the 3-NPA exposure during the early stages of development was not able to change locomotor behaviour. However, repeated intraperitoneal injections produced bradykinesia in adult zebrafish that closely resemble the locomotor pathology of the late-stage of HD.
|University of Quindío, Colombia
||#52 - Gina Marcela Jiménez-Vargas
||Traffic noise and plasticity in the advertisement call features of the poison frog Andinobates bombetes
For vertebrates there is good evidence supporting anthropogenic noise as a promotor of reversible changes (plasticity) in call features that could reduce signal masking. However, the evidence suggesting evolutionary changes in call features as a response to anthropogenic noise is controversial. The intensity of traffic noise is highest at low frequency; hence, calling at high frequency can reduce signal masking by noise and being an adaptive behavior. Males of the poison frog Andinobates bombetes in a habitat highly disturbed by traffic noise call at higher frequencies than conspecifics in less acoustic disturbed habitats. We used playbacks experiments with traffic noise at intensities of 75 dB to test whether calling males change spectral and temporal features of their advertisement call in an adaptive way. When submitted to traffic noise, 22 males increased the frequency of the call 116 Hz on average, but they did not changed call duration, call rate, or call intensity. Therefore, frogs would exhibit adaptive plasticity in call frequency when acoustic properties of the habitat change because traffic noise. It is possible that this plasticity may be a precursor of evolutionary changes in call frequency of A. bombetes if disturbance by anthropogenic noise prevails in the habitat.
|Indian Institute of Science Education and Research, Kolkata, India
||#53 - Purbayan Ghosh
||Cost of brood transport in an Indian ant during relocation
Ants represent the pinnacle of social evolution. They are eusocial insects occupying a diverse range of terrestrial ecosystems across an extraordinary geographical range. Ant colonies typically live in subterranean nests that shelter them from several biotic and abiotic stress factors. Nest provides a secure environment to rear developing brood (egg, larva, and pupae). In social insect colony, brood not only represents a large part of the colonies’ investment but also represents their fitness because brood ecloses into the next generation of reproductive(s) and workforce. But unlike other social insects, such as bees and wasps, ant colonies carry their brood while relocating to new nests. This ability to transport hundreds of offspring is unique to ants as only a few species across the animal kingdom are capable of transporting their offspring from one place to another. While brood transport will increase the colonies fitness it makes the relocation process more complicated in terms of time, organization and workforce required. Here, we experimentally investigated the short-term cost associated with brood transport during relocation in ants by performing manipulative experiments. By contrasting brood-enhanced (B+) and brood-depleted (B-) colonies with control colonies in terms of relocation dynamics and work organization in a primitively eusocial, tandem running ant Diacamma indicum, we accessed the impact of brood transport on relocation. From 43 relocation experiments with over 2100 unique ants, we found that increasing brood makes colonies less prone to relocate. However, the overall relocation dynamics and work organization remained unaffected in B+ and B- colonies compared to un-manipulated colonies. The additional brood in B+ is transported by enhanced coupled adult transport and brood transport. Thus, we conclude that the ability to integrate brood transport during relocation seamlessly has given ant colonies a competitive advantage against other social insects when they relocate and expand into new territories.
|Institute for Advanced Study in Toulouse, France
||#54 - Gonçalo Faria da Silva
||Kin discrimination and demography modulate patterns of sexual conflict
Recent years have seen an explosion of interest in the overlap between kin selection and sexual selection, particularly concerning how kin selection can put the brakes on harmful sexual conflict. However, there remains a significant disconnect between theory and empirical research. Whilst empirical work has focused on kin-discriminating behaviour, theoretical models have assumed indiscriminating behaviour. Additionally, theoretical work makes particular demographic assumptions that constrain the relationship between genetic relatedness and the scale of competition, and it is not clear that these assumptions reflect the natural setting in which sexual conflict has been empirically studied. Here, we plug this gap between current theoretical and empirical understanding by developing a mathematical model of sexual conflict that incorporates kin discrimination and different patterns of dispersal. We find that kin discrimination and group dispersal inhibit harmful male behaviours at an individual level, but kin discrimination intensifies sexual conflict at the population level.
|Ludwig Maximilian University of Munich, Germany
||#55 - Alexander Hutfluss
||The individuality in stability in birdsong and how it relates to male quality
Behavior varies among- and within-individuals. Furthermore, individuals may vary in their behavioral predictability or stability (namely, residual within-individual variance, RWV). While, for example, predator-prey-interactions might favor unpredictability, other contexts, e.g. mate attraction or male-male competition, might favor stable signaling of individual information. One prime example is birdsong, as certain traits are perceived as “attractive”; thus stable production of such traits could signal male quality. Although one would consequently expect among-individual differences in stability and links with reproductive success, few studies have investigated this. To investigate the existence and importance of RWV in birdsong, and whether it is plastic, we collected song recordings in 12 great tit populations in three consecutive years. Every breeding male was presented with a conspecific intruder four times per season, simulating territorial intrusions, resulting in hundreds of recordings. From these recordings we measured temporal and spectral features of song. Data was analyzed using double hierarchical mixed effect models, enabling us to estimate “individuality in stability” and the effects of environment and other traits on RWV. Our results fit the expectations, supporting the existence of individual differences in RWV. Furthermore, RWV shows short- and long-term repeatability, suggesting that these individual differences are stable over time. However, we did not find support for plasticity in RWV. Birds did not change their stability over the season, nor did differences in size or aggressiveness explain differences in stability. Our findings support the notion that stable production of attractive acoustic signals is a signal of quality in itself and that it might be targeted by sexual selection. Links with reproductive success, providing further insights into this, are currently investigated and will be presented.
|National Centre for Biological Sciences, India
||#56 - Smruti Pimplikar
||Dance followers across Asian honey bee species show similar behavioural patterns
Animals that live in social groups need to communicate amongst themselves to make decisions at the individual and the group level. Social communication systems are often multimodal and combine modulatory and information-bearing signals. One of the best examples of a sophisticated communication system is the honey bee waggle dance which stimulates nestmates to forage and encodes the location of a food source. Studies in foragers of various Apis species have revealed major differences in signals produced by the dancers. However, it is still unclear how the receivers perceive these varying signals. In this study, we compared the behaviour of dance followers in three Asian honey bee species Apis florea, Apis dorsata, and Apis cerana. Our major hypothesis was that differences in the behaviour of the followers would indicate that the species likely use different sensory signals in dance communication. We observed followers of all three Asian honey bee species during the dance and quantified the locations they occupied around the dancer as well as their median body orientations. In all three species, the highest number of followers positioned themselves lateral to the dancer, and the mean angle for the followers was around 90°. Our results show that the dance follower behaviour is highly conserved throughout all 3 Asian honey bee species. Consequently, species differences in the signals produced by the dancer bees are highly likely involved in attracting follower bees to the dancers and motivating the followers to initiate foraging.
|Weizmann Institute of Science, Israel
||#57 - Ehud Fonio
||How ants get their way when the wisdom of the crowd fails?
Wisdom of the crowd is based on the idea that in a large group, errors of judgement should cancel each other out. This allows the crowd to target an answer in a way superior to any of the individuals comprising the group, and has led to various applications (e.g., political and economic forecasting, evaluating nuclear safety, public policy, the quality of chemical probes, and possible responses to a restless volcano). Algorithms for extracting wisdom from the crowd are typically based on a democratic voting procedure. They are simple to apply and preserve the independence of personal judgment. However, democratic methods have their limitations. They are biased for shallow, lowest common denominator information, at the expense of novel or specialized knowledge that is not widely shared. Therefore there are situations in which this classic theory falls apart. Here we show how ants apply superior collective behavior that achieve a beneficial and efficient collective decision making process, even though the vast majority of the participating ants are holding a wrong opinion - a situation in which wisdom of the crowed would fail. This capability is based on the group ability to also empower minority opinions, thus leading to quick amplification of novel and relevant information that helps the group avoid stagnation and overcome relatively difficult obstacles.
|University of Sheffield, UK
||#58 - Andreagiovanni Reina
||Negative feedback may suppress variation to improve collective foraging performance
Social insect colonies use negative as well as positive feedback signals to regulate foraging behaviour. In ants and bees individual foragers have been observed to use negative pheromones or mechano-auditory signals to indicate that forage sources are not ideal, for example being unrewarded, crowded, or dangerous. Here we propose an alternative function for negative feedback signals during foraging, variance reduction. We show that while on average populations will converge to desired distributions over forage patches both with and without negative feedback signals, in small populations negative feedback reduces variation around the target distribution compared to the use of positive feedback alone. Our results are independent of the nature of the target distribution, providing it can be achieved by foragers collecting only local information. Since robustness is a key aim for biological systems, and deviation from target foraging distributions may be costly, we argue that this could be a further important and hitherto overlooked reason that negative feedback signals are used by foraging social insects.
|Université de Bretagne Occidentale, France
||#59 - Sabine Roussel
||Activity and consistency of a marine gastropod behaviour, Haliotis tuberculata, is modified in function of the presence of a hiding place
Animal personalities or behavioural syndromes are present when individuals show consistent differences in behaviour between situations, context or over time. Consistency of behaviour is a related concept to personality. Abalone are one of the largest marine mollusc, living hidden in crevices during day period, and foraging mainly during night time. However, the importance of a hiding place is often underestimated in laboratory conditions. The objective of this experiment was (1) to study the effect of a hiding place on the activity and foraging behaviour of abalone (2) to evaluate if consistency could be modified in the presence or absence of a hiding place. A total of 48 abalone were video-recorded during a 1-week period. Abalone were placed individually in aquaria containing a hiding place for half of the aquaria and no hiding place for the other half. Behaviour of each individual was recorded continuously 24 h a day during 7 days. Number of movement, total time spent moving, number of feeding bout as well as total time spent feeding were calculated for each day, for day and night period. A strong diurnal rhythm of abalone was observed during this experiment. When an abalone initiated a locomotor behaviour, it was for feeding most of the time. However, the time spent moving was little correlated to feeding duration or number of feeding bout. Significant individual consistency was observed for the locomotor behaviour as well as for the feeding behaviour. However, the absence of a hiding place in experimental set-up reduced the consistency of locomotion of individuals. This experiment highlights the importance to include a hiding place in experimental set-up when the species is using one in its ecological niche.
|Pontifical Catholic University of Rio Grande do Sul, Brazil
||#60 - Darlan Gusso
||Pyriproxyfen Exposure Impairs Cognitive Parameters and Alters Cortisol Levels in Zebrafish
Pyriproxyfen is one of the most used larvicides and insecticides; it acts as an analog of juvenile insect hormone (a growth regulator). Therefore, it is has been used as a strategical agent to combat the proliferation of mosquitoes, especially for the genus Aedes. It is highly toxic during all stages of mosquito development, suppresses metamorphosis, and interferes in insect reproduction and proliferation. Despite the increasing number of toxicological studies about larvicides and insecticides - with an indication of continuous use - there have been few studies about the effects of pyriproxyfen in non-target species such as fish. This study evaluated the effects of pyriproxyfen on behavioral, cognitive, and endocrine parameters in zebrafish. We exposed adult zebrafish to different pyriproxyfen (Pestanal®) concentrations (0.125, 0.675, and 1.75 mg/l) for 96 h (Protocol approved by the Institutional Animal Care Committee: 7546/2016). We analyzed behavioral parameters, memory, cortisol levels, and gene expression of the glucocorticoid receptor (gr) and corticotrophin-releasing factor (crf). The pyriproxyfen exposure did not alter locomotion (distance or mean speed), anxiety-like behavior (latency to enter to the top zone of the tank or time in the top zone of the tank), and social or aggressive behavior. However, there was an impaired inhibitory avoidance memory at all tested pyriproxyfen concentrations. Cortisol levels were reduced in exposed groups when compared to control or vehicle. However, gr and crf gene expression in pyriproxyfen-treated animals were unaltered. Taken together, these findings indicate that pyriproxyfen may induce cognitive impairment and altered cortisol levels in zebrafish, a non-target species.
|Pondicherry University, India
||#61 - Kajal Kumari
||Assessing Quantitative Preferences and Rationality of Shoaling Group Size Choices in Zebrafish (Danio rerio)
Living in groups may confer many direct and indirect benefits such as protection against predation and improved foraging efficiency, thereby affecting the survivability of the animal. Rational Choice theory, largely defined for human economic behavior, assumes that animals make decisions based solely on the assessed utility of items. However, the utility of an item may be context-dependent, with context influencing an animal’s perceived value of and choice of a given item compared to another item. Context can also refer to other, less preferred items that are deemed irrelevant - so we want to test the Independence of Irrelevant Alternatives (IIA) assumption of the rational choice theory. We conducted a study on social zebrafish where we assessed the context-dependence of their quantitative preferences for various shoal sizes. After an initial quantification of these preferences between binary options, we tested rationality and context-independent decision making by adding a third choice of the shoal to the initial two-choice set. We calculated the relative preference for the larger shoal across experimental trials with varying values of the third shoal size, to test the constant ratio rule s, which assumes that the preference between any two options is not dependent on third, irrelevant options. The findings suggest that fishes that show preferences for larger shoals do not show significant changes in their relative preference for the larger shoal in the presence of irrelevant alternatives and hence do not violate the principles of rationality. Our results from our binary choice experiments on shoal size depart from the literature, and we discuss shoal size choice as a possible paradigm for rationality tests in zebrafish.
|Rutgers University - Newark / New Jersey Institute of Technology, USA/td>
||#62 - Nicole Dykstra
||Relative contribution of division of labor and specialization to group efficiency
The success of a colony of social insects depends on its individual members correctly accomplishing a multitude of tasks such as foraging, colony defense, and brood care. A common strategy to achieve this is for labor to be divided among the colony, with groups of individuals performing the same task almost exclusively. However, most studies conflate division of labor – specific workers performing specific tasks – with worker specialization – not merely performing a task more often than other tasks, but performing the task better than one’s peers. That confusion limits our ability to determine the evolutionary relationships between division of labor and specialization and their respective impact on the collective output of the colony. Here, we use a simulation approach to measure the impact of worker specialization on colony efficiency when division of labor is either absent or present, decoupling the two concepts. In colonies without division of labor, our preliminary results suggest worker specialization is favored when colonies have low task variability; as the number of types of tasks increases, colonies with a larger proportion of specialists take longer to complete all tasks.
|University of Georgia, USA
||#63 - Supraja Rajagopal
||How does infection of group members affect collective performance?
While group living confers benefits like higher efficiency of foraging, brood care and defense against predators, social animals are also susceptible to an increased risk of parasitism. Past research has mainly focused on the effect of pathogen exposure on individual behavior and the disease transmission within a group. However, it has been little explored how the individual-level effects of pathogens can scale up to affect colony-level performance. In order to address this question, we have activated the innate immune system of the rock ant, Temnothorax rugatulus, by injecting a bacterial endotoxin (LPS, lipopolysaccharide). Our preliminary data show that the LPS-injected ants walk less, and with a lower average speed than the ones in the control groups who are injected with saline or not injected. Currently, we are planning to look at how the colony’s performance on foraging and house-hunting gets affected by the presence of these “sick” colony members. By manipulating proportions of sick members, we are also able to investigate the relationship between individual ability and collective performance.
|University of Georgia, USA
||#64 - Doreen Chaussadas
||Impacts of bio-loggers' weight on their carrier: is 5% of the body mass an acceptable charge to put on a Pigeon's back?
Recent technological advances enable researchers to collect data (movement, physiological, etc.), which were difficult to obtain. The idea of using an animal-borne device on a living animal dates as far back as 1962, and since then its use has been applied to many taxa across various disciplines. Yet we must consider its impact on the carrier. The weight of a bird-borne device is typically considered acceptable if it is less than 5% of the carrier’s body mass. However, we still know very little about this 5% ‘rule’; is it too light or too heavy and how does it affect flight? In this study, we will use homing pigeons (Columba livia) to explore the effect of device weight on flight performance using a light GPS logger and accelerometer. We will manipulate the device ‘weight’ by adding bicycle bearing ball (1 g each) to it. Our findings will be valuable not only for researchers working on animal behavior but also for anyone using animal-borne devices in a wide variety of disciplines.
|University of Buenos Aires, Argentina
||#65 - Muriel Pereyra
||Olfactory associative learning in Argentine ants
The Argentine ant, Linepithema humile, is native from South America but has been introduced worldwide during the last century, becoming one of the world’s main invasive species. Despite its global relevance, its learning abilities have surprisingly not been broadly explored. This species heavily relies on the trail pheromone to coordinate foragers’ orientation to food sources, but the question of whether Argentine ants can use olfactory memories for orientation during foraging remains unexplored. We studied its olfactory learning abilities in the frame of foraging. To study this, we trained ants to associate an odor spot with a reward, evaluating the individuals within a circular arena which was divided into two areas. One of the areas was in close proximity to the olfactory stimulus (linalool) and a sucrose solution was offered as reinforcement; in the other area, water was offered close to the control stimulus (mineral oil). We found that ants were able to learn an association between an odor and a reward in three trials and to use this memory for orientation towards the food when they were evaluated minutes after the training (implying a medium-term memory). Our results not only contribute to the understanding of this species' cognitive abilities and validate a simple protocol to study olfactory learning in the context of foraging in this species but they could also have implications in the development of new control strategies by, for instance, supplementing sugary toxic baits with odors in order to improve the learning and memory of bait location.
|Federal University of Paraná, Brazil
||#66 - Felipe Marcel Neves
||Recurrence analysis of ant activity behavior in different densities
The phenomenon of periodic oscillations in movement activity has been observed in ants of the genera Leptothorax and Temnothorax (small, cavity-dwelling ants), which exhibit periodic pulses of short-term activity at the colony level. Isolated individuals and small groups of workers of these species do not show periodic oscillations, but when their density increases, the predictability of dynamic activity becomes increasingly apparent. Although these results are intriguing, they have never been observed in other ant genera, nor has the transition to periodicity been well studied. Here we used recurrence quantification analysis (RQA) and recurrence plots (RPs) to compare and analyze the activity dynamics of ant species with different levels of social complexity and at different densities (1, 4 and 16 individuals). RQA and RPs are powerful nonlinear data analysis methods that quantify the number and duration of the phase space trajectory of the dynamical system, resulting in a detailed description of its behavior, including the quantification of dynamic patterns (stochastic to deterministic). Three species of ants were used in our study: Gnamptogenys striatula (Ectatomminae), Linepithema micans (Dolichoderinae), Pheidole rudigenis (Myrmicinae), as well as adults of a gregarious beetle species (Tenebrio molitor) for comparison. The local interactions among ant workers could explain the emergence of the oscillatory activity, thus we also quantify the frequency of the interactions between ant workers. Our results (i.e. 150 time series; 300 hours) show that the activity dynamics of ant groups are more predictable in comparison with isolated individuals and that periodic oscillations are caused by a higher number of local interactions, as expected. Interestingly, not only some ant species, but also beetles exhibit characteristic short-term periodic activity pulses in small groups of individuals, suggesting that such phenomena could be a by-product of the contact rate between individuals rather than an innate phenomenon of ant societies.
|University of Buenos Aires, Argentina
||#67 - Candela Medina
||Long term memory of a spatial learning task in the crab Neohelice granulata
In the wild, animals are able to recognize and remember specific locations related to food source and/or possible predation. In order to do so, long-term memories are formed, associating spatial cues with appetitive or aversive stimuli. Therefore, further understanding of spatial memories is a relevant question for behavioral neuroscience. With this in mind, we set to develop a novel paradigm for crab Neohelice granulata which is suitable for appetitive spatial conditioning. During the training session, animals are placed in a circular arena, which consists of plain white floor and walls, except for one striped quadrant. Interestingly, this quadrant is not only initially avoided by the animals, but this behavior is strongly modulated by the animal’s motivational state. The training protocol consisted of 5 minutes habituation to the training context, and 10 minutes of appetitive conditioning through associating palatable reinforcement with the striped section of the arena. When tested, 24 hours after training, conditioned animals spend more time in the striped section of the arena, relative to the plain white rest of the arena, compared to control animals. Importantly, we defined the parametric conditions for this novel paradigm (training session duration, unconditioned stimulus intensity, etc), as well as evaluating the protein synthesis dependence of the resulting long-term memory. Overall, this work provides evidence to establish the basis for a novel spatial paradigm in crab Neohelice granulata.
|University of Buenos Aires, Argentina
||#68 - Julian Dobler
||Differential Nezara viridula L. preference and survival, depending on soybean seed phenolics concentration
Nezara viridula L. stinkbugs are piercing-sucking Hemiptera insects that feed on soybean seeds (Glycine max L.), among other species. Soybeans produce different types of flavonoids and isoflavonoids (secondary phenolic metabolites) and some of these compounds are induced after feeding. It is believed that these metabolites mediate anti-herbivory mechanisms, though currently we do not know how phenolics affect insect behavior, neither individually nor collectively. Two aims were proposed: (1) to study the preference of N. viridula L. adult over a soybean cultivar that synthesizes high constitutive concentrations of isoflavonoids (Williams) vs. a soybean cultivar that synthesizes low concentrations (BRM) and (2) to evaluate N. viridula L. nymphs survival while feeding on diets with different Rutin concentrations (quercetin-3-O-rutinoside, soybean flavonoid). Aim “1” methodology consisted in measuring adults feeding location (Williams vs. BRM), over a 3-hour period. For objective “2”, methodology consisted in seed imbibition with different Rutin concentrations: high (4 mg/g), intermediate (2 mg/g), low (1 mg/g) and control (not detectable concentration). Our results show that stinkbug adults prefer to feed on seeds with low isoflavonoid concentrations (BRM plants), suggesting these phenolics could be responsible for this differential behavior. But when evaluating nymph survival over different Rutin concentrations, we found that there is a negative effect after high concentration (higher nymph mortality) and a positive effect after medium concentration (lower nymph mortality), both compared with control diet. Therefore, modifying compounds individually and at different concentrations could be the key to comprehend the role of plant response over herbivore insect behavior. Understanding these interactions in greater detail could led us into developing new tools to improve integrated pest management.
|Grambling State University, USA
||#69 - Hector Douglas
||Fluctuating asymmetry of bill fluorescence varies with bill size and brightness in Crested Auklets (Aethia cristatella)
Bilateral symmetry is theorized to be associated with developmental stability, and it is assumed to be a basis for mate choice. Fluctuating asymmetry refers to small random deviations in bilateral paired structures, assumed to result from stressors acting on developmental processes. We tested the symmetry of fluorescence in rictal plates of Crested Auklets (Aethia cristatella). Fluorescence was measured on the anterior surface of accessory bill plates (rictals) of samples from Little Diomede (LD) and St. Lawrence I. (SL), Alaska. A blue argon laser (488 nm) was used for excitation in combination with a 200 µm multimode fiber and Ocean Optics HR2000 visible light spectrometer (0.9 nm resolution) for detection. We used mean differences as the measure of symmetry, and we defined this as the difference in fluorescence between right and left rictal plates. We compared variability between and within individuals with One-way ANOVA and Tukey’s HSD post-hoc test. Crested auklets differed in symmetry, and one third of birds at each colony had significantly lower symmetry. Mean intensity and mean difference were negatively correlated at LD (r s 1-tailed = -0.61, p=0.03, n=10); higher fluorescence was associated with lower mean difference between right and left sides, greater symmetry. Culmen was correlated with mean difference in males (r s 1-tailed = 0.51, p=0.02, n=18) and at SL (r s 1-tailed = 0.62, p=0.02, n=11); larger bills were associated with lower symmetry. Fluorescence is perceived as brightness, and this brightness is proportional to the concentration of fluorescent molecules present. The bill functions as an armament, and it size is a projection of power. Rictal plates accentuate size, and their geometry accentuate brightness. Bill brightness is attractive to crested auklets, as revealed by our experiments. Bilaterally symmetrical feather plumes are a sexually selected trait in this species. Therefore, bilateral symmetry in bill fluorescence is also likely to be important in mate choice.
|University of the Republic, Uruguay
||#70 - Federico Reyes
||Hormonal underpinnings of agonistic contests in annual fish: fighting in an extreme environment
Conspecifics fight for limiting resources such as food, territory or mates. Agonistic behavior is a ubiquitous behavior exhibited by a wide variety of animals that involves the exchange of both aggressive and submissive displays. Androgens both promote aggression and respond to social challenges. In addition, androgen-estrogen conversion by the enzyme aromatase, plays an important role in the regulation of male aggression. Our goal was to explore the role of sex steroids in the regulation of agonistic behavior in the South American annual killifish Austrolebias reicherti. Annual fish inhabit temporary ponds that dry out completely during summer. Adults deposit desiccation-resistant eggs in the substrate that hatch when the pools refill again the next year. Once sexually mature, adults breed continuously and males engage in highly aggressive fights. We performed dyadic contests with socially naïve males and measured plasmatic levels of 11-ketotestosterone (11KT, main teleost androgen), and 17β-estradiol (E2) in dominants, subordinates (N11KT =8, NE2 =9), and controls (males with no opponents) (N11KT control =8, NE2 control =9). In addition, we assessed the role of the estrogenic pathway by performing dyadic contests treated with an aromatase inhibitor (Fadrozole: FAD). Dominants had higher levels of 11KT than subordinates, but did not differ from control males. Levels of E2 did not differ among the three groups. Fights under FAD treatment (N=8) were overall less aggressive than control fights (N=10), suggesting that androgen-estrogen conversion is a key modulatory pathway of Austrolebias’ male aggression. These results suggest that androgens are positively associated with social status, and that A. reicherti males may maintain high androgen levels by default and decrease them only upon subordination, in line with the extremely short lifespan and single breeding opportunity of annual fish. This research represents the first study on the hormonal underpinnings of agonistic behavior in a vertebrate species exhibiting annualism.
|Instituto de Investigaciones Forestales y Agropecuarias Bariloche, Argentina
||#71 - Analía Mattiacci
||Sugar and protein response threshold on pre-foraging and foraging workers of social wasp V. germanica
Division of labor among workers is considered to be a major reason behind the ecological success of eusocial insects. Age polyethism is the most common mechanism, by which workers switch tasks according to their age. Thus, duties inside the nest such as nursing or ventilating are performed during the first days of life while outside duties such as guarding, and foraging are performed at a later age. Age polyethism underlying mechanisms involve nutrition, age, and reproductive status of the individuals. Such variables interact to modulate appetitive stimuli perception. Here, we evaluate and describe the appetitive perception capability of workers of the eusocial wasp, Vespula germanica, and the influence of age on this behavior. Pre-foraging (newly emerge) and forager wasps (several days old) received antennal stimulation with an increasing concentrations series of carbohydrate and protein-rich solution. Acceptance or rejection was registered. We show that wasps display an ingestion threshold (Maxilla-labium complex extension response score) for both resources. However, each resource shoots a different response curve. We also show that Maxilla-labium complex extension response scores were not significantly different in pre-foragers and foragers wasps. Modulation of the responsiveness to appetitive stimulus does not seem to be a crucial underlying mechanism of age polyethism in V. germanica workers.
|University of São Paulo, Brazil
||#72 - Melissa Guirelli
||Jealousy Behaviour in Dogs with Human Rivals
Jealousy in non-human animals is controversial. For being considered a secondary emotion, it seems to require complex cognitive abilities supposed to be found only in humans. However, the few existing experimental studies on jealousy in dogs have shown that the reaction of them when ignored by their owners, which starts to pay attention to another animal (rival), is functionally like that of children's jealousy reactions observed in similar situations. Another indication of jealous behavior in dogs refers to the fact jealous has been frequently pointed out as a behavior problem by dog owners and has been cited as an issue to be solved in many trainers' books dogs. There are missing studies of jealousy in dogs with a human as a rival and the missing of scientific empirical evidence about treatments. Considering in basic research with non-human animals, one way of adding a new function to a stimulus is through association with another appetitive or aversive stimulus, the purpose of this study is to compare the effects of jealousy situation in dogs when the rival is a human and its changes after a rival-food pairing. In this study, two dogs were exposed to a situation in which their owner and a stranger (rival) hug each other, while they ignore the dog (jealousy situation). After that, one of the dogs was feed by the stranger (Pavlovian conditioning), and the other one was ignored by them. A second jealousy situation was applied again. Except by dog after the Pavlovian conditioning, all the subjects showed owner-oriented behavior and whining in all the situations, results like previous studies with dogs and children. Besides, the experiment suggests that rival-food pairing may decrease the incidence of behaviors characterized as jealous with the same rival in similar situations. A study with a greater n is recommended.
|University of Cambridge, UK
||#73 - Swastika Issar
||How does resource specialisation evolve?
A key prediction of ecological theory is that competition for resources drives the evolution of specialised resource use, as a means to prevent costly competition. One possible outcome is the evolution of different genetic morphs that specialise on different resources. Although correlational evidence exists that is consistent with this idea, there is surprisingly little to suggest that competition causes resource specialisation. Burying beetles are an ideal species with which to test this prediction. They require the carcass of a small vertebrate like a mouse or a songbird for reproduction, but carcasses can be scarce and competition to secure ownership is correspondingly intense. We tested for evidence of divergence in resource use in three woodland populations of burying beetles by manipulating resource type and availability on a local spatial scale. We found that burying beetle populations exhibit differential preference for carcass resources and that there is a genomic basis for this differential preference. We found divergence at around 50 loci in each of the three populations, some of which are associated with olfaction. Finally, we tested whether divergent selection on resource availability can cause populations to differentiate by experimentally evolving populations on different carcass resources for successive generations. Our behavioural experiments revealed that beetles quickly exhibited a preference for the type of carrion they developed upon as larvae. Therefore, through our integrative approach combining field studies, genomic sequencing and experimental evolution, we propose a link between competition, resource availability and specialisation.
|Rice University, USA
||#74 – Lisa O’Bryan
||Contact Calls and Collective Departure in Wild Baboons
Most studies of collective movement behavior examine how individuals respond to visual information about others’ positions and behavior. However, communication has the potential to enhance, modify or supplement visual cues. For example, many species produce signals which are believed to convey readiness to depart following a period of rest or foraging. In addition, there is evidence that vocalizations can impact the trajectory of group movements. Nevertheless, studying these topics is challenging due to the need to collect data on the communication and movement behaviors of multiple group members. We approached this challenge by using bio-loggers to study the role contact calls play in the collective departure decisions of wild chacma baboons (Papio ursinus). We fitted nine adult baboons (60% of adults) with bio-loggers that recorded GPS location, accelerometer data and audio over 30 days during June 2016 at Tsaobis Nature Park in Namibia. We trained a deep neural network to detect grunts in the continuous audio streams and used GPS data to determine the time of group departure from the morning sleeping cliff and the departure trajectory. Using these data, we are testing the prediction that a peak in group-wide grunting behavior aligns with, or shortly precedes, the timing of departure. In contrast to our hypothesis, preliminary results indicate that peaks in grunting behavior occur during or following departure. Upcoming work will test how grunting behavior influences the direction of group departure. Results of our study will clarify the role vocal communication plays in the collective movement of animal groups.
|University of Turku, Finland
||#75 – Laura Zanette
||The influence of the social environment on parasitic infection of calves and adults in semi-captive Asian elephants
Parasites contribute to the selection on host fitness, regulation of population dynamics, and impact trophic interactions. However, observed levels of infection are shaped by environmental, parasite- and host-specific factors, leading to variation in parasitism between hosts. In social mammals, mounting evidence supports the idea that the social environment also influences this dynamic, yet how sociality shapes infection is contested; on the one hand, heightened social interactions can lead to improved individual health and fitness which could mitigate fitness costs of higher parasite loads. Conversely, proximity to parasitized conspecifics presents costs via elevated exposure to and transmission of infection. Moreover, few studies investigate the influence of sociality on infection considering other key influencing factors, such as age, environment and social group structure. Here, we study the effect of the social environment on infection by gastro-intestinal nematodes, specifically Strongyloides spp. and strongyles, in an endangered, social mammal, the Asian elephant Elephas maximus. Previous studies showed that calves (~5 years) carry the highest nematode burdens (assessed by faecal egg counts) compared to any other ages, and have elevated risk of parasite-associated mortality. Using an extensive dataset of repeated FECs from known individuals (n = 1728 / 239 elephants), we determined how the presence of highly parasitized hosts (calves) within working groups (3 - 12 individuals) affected infection in other group members, specifically for 1) other calves and 2) adult elephants present in a group. Accounting for differences in environmental variation and host group size, we show that the presence of parasitized calves, increases infection in other 'at-risk' hosts. Our results provide new insights as to how group composition may interact with other aspects of host-parasite dynamics to shape infection, but also contribute to elephant management and welfare.
|University of Tours, France
||#76 – Fernando Guerrieri
||Habituation to a visual danger stimulus is context-specific in mosquito larvae (Aedes aegypti)
Habituation is a form of non-associative learning defined as the progressive and reversible decrease in response to a specific reiterative innocuous stimulus. Nevertheless, habituation is not only stimulus-specific, but also context-specific, indicating that some kind of associative component between the context and the stimulus occurs. Here, we studied visual context-specificity in habituation in the mosquito larvae Aedes aegypti. Mosquito larvae live in small bodies of water and perform a stereotyped escape response when a moving object projects its shadow on the water indicating a potential risk of predation. Repeated presentations of the shadow alone induce habituation evinced by a decrease in the response. In this work, larvae were individually placed in Petri dishes. Underneath, black, white or black-white striped cardboards were placed producing a specific background (visual context). Larvae were presented over the course of 15 trials with a shadow produced by a cardboard square (training phase). Naïve larvae performed the escape response, whilst most trained larvae no longer responded to the shadow due to habituation, despite the visual context. Following, the background was shifted and the stimulus was presented once again (test phase). In the test phase, each time the background was shifted, larvae responded to the stimulus, proving that habituation was context-dependent. Data were analysed using a Bayesian model selection procedure over a series of proposed models. The selected Bayesian model, integrated four parameters explaining and describing the observed behaviour: habituation rate depending on context + asymptotic response + autoregression+ dishabituation depending on context). We conclude that an associative component exists in habituation, linking the stimulus to a specific visual context.