How animals learn from each other

Disentangling genetic, plastic and social learning drivers of sex-specific foraging behaviour in Trinidadian guppies (Poecilia reticulata)

Evolutionary biologists have long been interested in parsing out the roles of genetics, plasticity and their interaction on adaptive trait divergence. Since males and females often have different ecological and reproductive roles, separating how their traits are shaped by interactions between their genes and environment is necessary and important. Here, we disentangle the sex-specific effects of genetic divergence, developmental plasticity, social learning and contextual plasticity on foraging behaviour in Trinidadian guppies (Poecilia reticulata) adapted to high- or low-predation habitats. We reared second-generation siblings from both predation regimes with or without predator chemical cues, and with adult conspecifics from either high- or low-predation habitats. We then quantified their foraging behaviour in water with and without predator chemical cues. We found that high-predation guppies forage more efficiently than low-predation guppies, but this behavioural difference is context-dependent and shaped by different mechanisms in males and females. Higher foraging efficiency in high-predation females is largely genetically determined, and to a smaller extent socially learned from conspecifics. However, in high-predation males, higher foraging efficiency is plastically induced by predator cues during development. Our study demonstrates sex-specific differences in genetic versus plastic responses in foraging behaviour, a trait of significance in organismal fitness and ecosystem dynamics.

Social-pair judgment bias testing in slow-growing broiler chickens raised in low- or high-complexity environments

Impacts of environmental complexity on affective states in slow-growing broiler chickens (Gallus gallus domesticus) are unknown. Chickens' performance in judgment bias tests (JBT) can be limited as they are tested individually, causing fear and anxiety. The objectives were to apply a social-pair JBT to assess the effect of environmental complexity on slow-growing broiler chickens` affective states, and assess the impact of fearfulness, anxiety, and chronic stress on JBT performance. Six-hundred Hubbard Redbro broilers were housed in six low-complexity (similar to commercial) or six high-complexity (permanent and temporary enrichments) pens. Twelve chicken pairs were trained (1 pair/pen, n = 24 chickens) using a multimodal approach (visual and spatial cues), with reward and neutral cues of opposing color and location. Three ambiguous cues were tested: near-positive, middle, and near-neutral cues. Approach and pecking behavior were recorded. Eighty-three percent of chickens (20/24) were successfully trained in 13 days. Fearfulness, anxiety, and chronic stress did not impact chickens' performance. Chickens successfully discriminated between cues. Low-complexity chickens approached the middle cue faster than high-complexity chickens, indicating that they were in a more positive affective state. The environmental complexity provided in this study did not improve affective states in slow-growing broiler chickens compared to a control. A social-pair JBT resulted in excellent learning and testing outcomes in slow-growing broilers.

Dairy cows did not rely on social learning mechanisms when solving a spatial detour task

As herd-living animals, cattle have opportunities to observe and learn from others. While there is evidence of simpler processes of information transfer in cattle (social facilitation and stimulus enhancement), true social learning mechanisms in cattle remain largely unexplored. This study aimed to investigate if dairy cows possess cognitive abilities to acquire new behavior through social learning in a spatial detour task. Thirty-two dairy cows (ages 2–9 years) participated in the study. A food reward was placed behind a U-shaped formation (4 x 2 m), allowing the cows to see but not reach the reward without first detouring around the obstacle. The U-shape provided two routes (~18 m walking distance) to the reward, of which one was used for demonstration. Two cows were demonstrators and 30 cows were divided into two groups, assigned as either observers of demonstration (n = 15) or controls not observing demonstration (n = 15). Cows had three attempts (trials) to solve the task. Response variables were: success, latency to reach the reward, concordance in choice of route to detour, and time spent facing the test arena before each trial started. The study found no significant differences in success or latency between observers and controls, although observers spent a greater proportion of the time before trials facing the test arena. However, successful observers tended to be faster than successful controls. Individual cows were generally consistent in their choice of route, and cows choosing the demonstrated route were significantly faster than cows that did not. Success in solving the task decreased over trials, likely due to decreasing food motivation. Age had a significant effect on success in 2^nd and 3^rd trial, with younger cows being more successful. The lacking effect of treatment on success suggests that the age effect may be explained by a higher motivation, rather than social learning. Adding to the sparse knowledge of social learning in farm animals, these results indicate that cows did not utilize social learning mechanisms when solving the detour task. Future research should focus on clarifying whether cattle possess cognitive abilities necessary for social learning, as well as if /when social learning is a primary strategy.

A Cage Is a Cage, Unless You Educate. Rhetoric Negatively Impacts Support for a Novel Housing System for Laying Hens Unless the Public Are Educated

It has been proposed that terminology on commercially available eggs can impact the manner in which the eggs are discussed and ultimately consumer support. In this paper we tested if the label of ‘furnished cage’ eggs is a barrier for its support in Australia. Furthermore, we examined if educational interventions could change support and the way furnished cages were discussed. Survey participants (n = 1,157) were recruited by a stratified random sample of Australian adults. The participants were surveyed on their demographics, attitudes toward the poultry industry and animal welfare, and their egg buying behavior. Participants were randomly assigned to one of four treatment groups; two control groups and two educational groups. Participants were shown one of three videos, the control groups were shown a video with general information about chickens, the educated groups were shown one of two almost identical videos that educated them on aspects of the egg-laying industry in Australia, and the welfare implications of different housing systems including furnished systems. The only difference between the two educational videos was the name given to the furnished housing system; one group was introduced to furnished cages, the other was introduced to furnished coops. Educated participants were more likely to support furnished eggs and discuss them more positively than the control groups. When asked to discuss their support for furnished systems, control group participants exposed to the term cage were more likely to discuss the impacts of caged environments than the other treatment groups. The study suggests any negative impacts of housing system terminology can be mitigated through educational interventions.

Low-rank Gallus gallus domesticus chicks are better at transitive inference reasoning

A form of deductive reasoning, transitive inference, is thought to allow animals to infer relationships between members of a social group without having to remember all the interactions that occur. Such an ability means that animals can avoid direct confrontations which could be costly. Here we show that chicks perform a transitive inference task differently according to sex and rank. In female chicks, low-ranking birds performed better than did the highest ranked. Male chicks, however, showed an inverted U-shape of ability across rank, with the middle ranked chicks best able to perform the task. These results are explained according to the roles the sexes take within the group. This research directly links the abilities of transitive inference learning and social hierarchy formation and prompts further investigation into the role of both sex and rank within the dynamics of group living.

Judgement Bias in Miniature Donkeys: Conditioning Factors and Personality Links

Expectation-related bias may configure individuals' perception of their surrounding environment and of the elements present in it. This study aimed to determine the repercussions of environmental (weather elements) or subject-inherent factors (sex, age, or personality features) on judgment bias. A cognitive bias test was performed in eight Miniature jennies and four jacks. Test comprised habituation, training and testing phases during which subjects were trained on how to complete the test and scored based on their latency to approach an ambiguous stimulus. A questionnaire evaluating eleven personality features was parallelly completed by three caretakers, five operators and two care assistants to determine the links between personality features and judgment bias. Adjusted latencies did not significantly differ between sexes (Mann-Whitney test, p > 0.05). Although Miniature donkeys can discriminate positive/negative stimuli, inter-individual variability evidences were found. Such discrimination is evidenced by significant latency differences to approach positive/negative stimuli (33.7 ± 43.1 vs. 145.5 ± 53.1 s) (Mann-Whitney test, p < 0.05). Latencies significantly increased with patience, indicative of an expression of pessimism. Better understanding judgement bias mechanisms and implications may help optimize routine handling practices in the framework of animal welfare.

Influence of creep feeder position on the behavior and performance of preweaning piglets and sows in a hot climate environment

The use of creep feeding for preweaning piglets is important to improve the performance of the piglets. The objective of this experiment was evaluate the effect of using or altering the position of piglet's creep feeder during lactation on piglet's performance and on behavior of piglets and sows kept in a hot climate environment. Forty-five sows and their litters at 10 days of lactation were randomly distributed into three treatments: front feeder (FF) - near the side of the sow's head; back feeder (BF) - near the side of the rump of the sow; and no feeder (NF). All piglets were weighed individually to evaluate the average weight, weight gain and coefficient of variation of the weight. Behavior assessments of the piglets and sows were recorded in 3 period. At 15 and 21 d, piglets of the FF treatment were heavier (P ≤ 0.0001) than piglets of the other treatments. At 10-21d piglets of FF treatment had 76.2% less belly nosing behavior than the NF piglets (P=0.015). The treatments had no impact on behavior of the sows. The creep feeders positioned in the front of the farrowing crate increased piglet growth rate and decreased frequency of belly nosing behavior.

Management and Feeding Strategies in Early Life to Increase Piglet Performance and Welfare around Weaning: A Review

The performance of piglets in nurseries may vary depending on body weight, age at weaning, management, and pathogenic load in the pig facilities. The early events in a pig's life are very important and may have long lasting consequences, since growth lag involves a significant cost to the system due to reduced market weights and increased barn occupancy. The present review evidences that there are several strategies that can be used to improve the performance and welfare of pigs at weaning. A complex set of early management and dietary strategies have been explored in sows and suckling piglets for achieving optimum and efficient growth of piglets after weaning. The management strategies studied to improve development and animal welfare include: (1) improving sow housing during gestation, (2) reducing pain during farrowing, (3) facilitating an early and sufficient colostrum intake, (4) promoting an early social interaction between litters, and (5) providing complementary feed during lactation. Dietary strategies for sows and suckling piglets aim to: (1) enhance fetal growth (arginine, folate, betaine, vitamin B12, carnitine, chromium, and zinc), (2) increase colostrum and milk production (DL-methionine, DL-2-hydroxy-4-methylthiobutanoic acid, arginine, L-carnitine, tryptophan, valine, vitamin E, and phytogenic actives), (3) modulate sows' oxidative and inflammation status (polyunsaturated fatty acids, vitamin E, selenium, phytogenic actives, and spray dried plasma), (4) allow early microbial colonization (probiotics), or (5) supply conditionally essential nutrients (nucleotides, glutamate, glutamine, threonine, and tryptophan).

Broiler Chicks' Motivation for Different Wood Beddings and Amounts of Soiling

Simple Summary

Many animals move excreta—or feces—away from resting areas to avoid attracting predators and spreading disease. However, today’s farms raise broiler (meat) chickens in large barns with stocking densities that prevent the birds from segregating their excreta. Moreover, whether or not chickens would prefer to avoid their excreta is unknown. Understanding what litter conditions chickens prefer can help inform farming practices. Therefore, this experiment aimed to assess chicks’ motivation to access unsoiled bedding or soiled litter. We used six pens of six to seven broiler chicks—each pen divided into two compartments by a barrier containing two one-way push-doors. The ‘home’ compartment contained soiled wood shavings, while the ‘treatment’ (T) compartment contained either aspen wood shavings, pine and spruce wood shavings, soiled pine and spruce wood shavings, ammonia reductant treated soiled pine and spruce wood shavings, or a feed treatment as a gold standard. To determine the chicks’ motivation to access the resources, the door leading into T weighed 0% (lifted), 10%, 20%, or 30% of the chicks’ body weight. The combination of time spent in T, number of visits to T, and average maximum weight pushed to access T were used to measure motivation. Chicks showed equal motivation for all substrates and preferred feed over all substrates. However, future experiments must explore chicks’ preference and motivation over the long-term in commercial conditions.

Abstract

In the wild, excreta soiled surroundings can attract predators and spread disease. Yet, farmers rear broiler chicks in large barns with stocking densities that prevent excreta segregation. To measure chicks’ motivation to access unsoiled bedding or soiled litter (collectively, substrates) we used 40 16-day-old broiler chicks who were divided into six two-compartment pens. The ‘home’ compartment (H) contained soiled wood shavings, while the ‘treatment’ compartment (T) contained either aspen wood shavings, pine and spruce wood shavings, soiled pine and spruce wood shavings, ammonia reductant treated soiled pine and spruce wood shavings, or a feed treatment as a gold standard. The barrier separating the compartments had two one-way push-doors that chicks pushed to access a resource. The chicks’ motivation was measured by the average maximum weight pushed to access each resource. The door leading to T weighed 0% (raised), 10%, 20%, or 30% of the chicks’ body weight, and chicks could return to H via a raised (for 0%) or unweighted door. Our findings indicate that chicks worked hardest for feed, but paid a lower, equal price to access all substrates. With increasing door weight, chicks visited less and spent less time with the substrates. Therefore, as chicks themselves do not avoid litter that could have potential negative effects on their well-being, it is important that farmers diligently monitor litter conditions as their primary care-takers.

Social attention biases in juvenile wild vervet monkeys: implications for socialisation and social learning processes

The concept of directed social learning predicts that social learning opportunities for an individual will depend on social dynamics, context and demonstrator identity. However, few empirical studies have examined social attention biases in animal groups. Sex-based and kinship-based biases in social learning and social attention towards females have been shown in a despotic and female philopatric primate: the vervet monkey (Chlorocebus pygerythrus). The present study examined social attention during the juvenile period. Social attention was recorded through 5-min focal observations during periods of natural foraging. Kin emerged as the most important focus of social attention in juveniles, intensified by biased spatial proximity towards matrilineal related members. The highest-ranking conspecifics were more frequently observed by juveniles than low-ranking ones. Additionally, younger and orphaned juveniles showed higher levels of social attention overall, compared to other age categories. No effect of the juvenile's hierarchical rank was detected, suggesting that the variation in social attention recorded reflects different biases and stages of social learning and socialisation, rather than social anxiety. Juvenile females tended to exhibit a dominance-based bias more strongly than did males. This might be explained by a greater emphasis on attaining social knowledge during juvenile socialisation in the philopatric sex. Moreover, despite a preferred association between juveniles, social attention was more often directed to adults, suggesting that adults may still be more often chosen as a target of attention independent of their dominance rank.

Human Demonstration Does Not Facilitate the Performance of Horses (Equus caballus) in a Spatial Problem-Solving Task

Simple Summary

Horses were confronted with a spatial problem-solving task in which they had to detour an obstacle. Individuals that observed a human demonstrating how to solve the task did not solve the task more often or faster compared with a control group without demonstration. However, horses of both the treatment and control group detoured the obstacle faster over trials. Together with previous research, our results illustrate that horses do not seem to rely on social information when solving a spatial problem-solving task.

Abstract

Horses’ ability to adapt to new environments and to acquire new information plays an important role in handling and training. Social learning in particular would be very adaptive for horses as it enables them to flexibly adjust to new environments. In the context of horse handling, social learning from humans has been rarely investigated but could help to facilitate management practices. We assessed the impact of human demonstration on the spatial problem-solving abilities of horses during a detour task. In this task, a bucket with a food reward was placed behind a double-detour barrier and 16 horses were allocated to two test groups of 8 horses each. One group received a human demonstration of how to solve the spatial task while the other group received no demonstration. We found that horses did not solve the detour task more often or faster with human demonstration. However, both test groups improved rapidly over trials. Our results suggest that horses prefer to use individual rather than social information when solving a spatial problem-solving task.

Thinking chickens: a review of cognition, emotion, and behavior in the domestic chicken

Domestic chickens are members of an order, Aves, which has been the focus of a revolution in our understanding of neuroanatomical, cognitive, and social complexity. At least some birds are now known to be on par with many mammals in terms of their level of intelligence, emotional sophistication, and social interaction. Yet, views of chickens have largely remained unrevised by this new evidence. In this paper, I examine the peer-reviewed scientific data on the leading edge of cognition, emotions, personality, and sociality in chickens, exploring such areas as self-awareness, cognitive bias, social learning and self-control, and comparing their abilities in these areas with other birds and other vertebrates, particularly mammals. My overall conclusion is that chickens are just as cognitively, emotionally and socially complex as most other birds and mammals in many areas, and that there is a need for further noninvasive comparative behavioral research with chickens as well as a re-framing of current views about their intelligence.

Anti-predator behaviour of adult red-legged partridge (Alectoris rufa) tutors improves the defensive responses of farm-reared broods

The aim of this work was to improve natural anti-predator behaviour of farm-reared gamebirds. We evaluated the anti-predator behaviour of reared red-legged partridge Alectoris rufa chicks kept in brooder houses in large groups (>350 chicks), trained and not trained by parent red-legged partridges acting as experienced tutors. The experiment consisted of two conditioned tests (a raptor model and a human) and two control tests, which were conducted during three consecutive phases of life (1-4, 15-17 and 30-32 d after hatching). The motor anti-predator behaviour, its duration, the intensity of response in chicks and alarm calls elicited by adults were recorded. Tutors elicited aerial alarm calls (76% of tests) and showed prolonged crouching (59% of tests) in response to the raptor model whereas uttering the ground alarm call (73% of tests) and showing vigilance behaviour (78% of tests) was the main pattern during the human test. Trained and not trained chicks showed similar motor behaviour in response to the raptor model (crouching) and the human test (escaping), but frequency of strong responses (all chicks responding) from chicks trained with tutors was double that of chicks trained without them, and chicks trained with tutors showed a higher frequency of long responses (41-60 s). This study indicates that anti-predator training programmes before release may improve behaviour of farm-reared partridges which may confer benefits to survival of birds.

Invited review: Effects of group housing of dairy calves on behavior, cognition, performance, and health

Standard practice in the dairy industry is to separate the calf and dam immediately after birth and raise calves in individual pens during the milk-feeding period. In nature and in extensive beef systems, the young calf lives in a complex social environment. Social isolation during infancy has been associated with negative effects, including abnormal behavior and developmental problems, in a range of species. Here, we review empirical work on the social development of calves and the effects of social isolation in calves and other species; this evidence indicates that calves reared in isolation have deficient social skills, difficulties in coping with novel situations, as well as specific cognitive deficits. We also review the practices associated with group housing of dairy calves, and discuss problems and suggested solutions, especially related to cross-sucking, competition, aggression, and disease. The studies reviewed indicate that social housing improves solid feed intakes and calf weight gains before and after calves are weaned from milk to solid feed. Evidence regarding the effects of social housing on calf health is mixed, with some studies showing increased risk of disease and other studies showing no difference or even improved health outcomes for grouped calves. We conclude that there is strong and consistent evidence of behavioral and developmental harm associated with individual housing in dairy calves, that social housing improves intakes and weight gains, and that health risks associated with grouping can be mitigated with appropriate management.

Horses fail to use social learning when solving spatial detour tasks

Social animals should have plenty of opportunities to learn from conspecifics, but most studies have failed to document social learning in horses. This study investigates whether young Icelandic horses can learn a spatial detour task through observation of a trained demonstrator horse of either the same age (Experiments 1 and 2, n = 22) or older (Experiment 3, n = 24). Observer horses were allowed to observe the demonstrator being led three times through the detour route immediately before being given the opportunity to solve the task themselves. Controls were allowed only to observe the demonstrator horse eating at the final position, but not the demonstration of the route. Although we found a tendency towards better performance by observer horses in the second experiment, we were unable to repeat this result in a similar set-up with a new group of horses and older, dominant demonstrator horses. We conclude that horses exposed to prior demonstration did not perform better than control horses in solving spatial detour tasks.

Is the hibiscus harlequin bug aposematic? The importance of testing multiple predators

Aposematism involves predators learning conspicuous signals of defended prey. However, prey species utilize a wide range of chemical (or physical) defenses, which are not likely to be equally aversive to all predators. Aposematism may therefore only be effective against a physiologically sensitive subset of potential predators, and this can only be identified through behavioral testing. We studied the emerging model organism Tectocoris diophthalmus (Heteroptera: Scutelleridae), an aposematically colored but weakly defended shieldback stinkbug, to test the efficacy of its defenses against a suite of predator types. We predicted the bugs' defenses would be ineffectual against both experienced and naïve birds but aversive to predaceous insects. Surprisingly, the opposite pattern was found. Both habituated wild passerines and naïve chickens avoided the bugs, the chickens after only one or two encounters. To avian predators, T. diophthalmus is aposematic. However, praying mantids showed no repellency, aversion, or toxicity associated with adult or juvenile bugs after multiple trials. Comparison with prior studies on mantids using bugs with chemically similar but more concentrated defenses underscores the importance of dose in addition to chemical identity in the efficacy of chemical defenses. Our results also emphasize the importance of behavioral testing with multiple ecologically relevant predators to understand selective pressures shaping aposematic signals and chemical defenses.

A few days of social separation affects yearling horses' response to emotional reactivity tests and enhances learning performance

Learning performance is influenced by emotional reactivity, low reactivity being generally beneficial. Previous experiments show that emotional reactivity can be modified after a period of social isolation. We hypothesized that eleven days of isolation would affect yearlings' emotional reactivity and improve their learning abilities. Twenty-five yearlings were divided into two groups: 12 were continuously isolated for 11 days (isolated) and 13 stayed together (control). During the period of isolation, all yearlings underwent two learning tasks: a habituation procedure in which a novel object was presented for 120 s every day, either when the horse was alone (isolated) or with conspecifics (control); an instrumental learning task in which the yearling had to walk forwards or backwards to obtain a food reward. At the end of the isolation period, animals performed tests to assess aspects of emotional reactivity: reactivity to novelty, to humans, to social separation, to suddenness and to sensory stimuli. Results showed that isolated yearlings habituated more to the novel object than controls and performed better in the instrumental task. Moreover, they were less reactive to novelty, to social separation and to suddenness than controls. Overall, these data suggest that the better performance of isolated yearlings could be explained by a decrease in their emotional reactivity. This article is part of a Special Issue entitled: insert SI title.

Effects of environmental enrichment and loose housing of lactating sows on piglet performance before and after weaning

We investigated effects of loose housing of the sow during lactation and enrichment of the pen pre- and postweaning on performance of newly weaned piglets. Before weaning, piglets (n = 320) were housed in an enriched (straw, wood shavings, peat, and branches) or barren pen with a confined or loose-housed sow (n = 32). Loose-housed sows and their piglets could eat together from a family feeder, whereas confined sows and piglets had separate feeding troughs. Piglets (n = 256) were mixed postweaning, and 4 piglets from each litter were relocated to a barren pen (n = 32 pens) and 4 other piglets were housed in an enriched pen (n = 32 pens). Growth from d 15 until weaning was greater for piglets from enriched pens (4.38 ± 0.29 vs. 4.71 ± 0.21 kg/pig, P < 0.05) and tended to be greater for piglets with a loose-housed sow compared with piglets with a confined sow (4.41 ± 0.26 vs. 4.67 ± 0.24 kg/pig, P = 0.10). Preweaning feed intake was not affected by preweaning conditions (P > 0.25). Piglets from enriched preweaning pens ate more in the first 2 d postweaning than piglets from barren pens (first 48 h, barren 0.45 ± 0.05 kg/pig, enriched 0.53 ± 0.04 kg/pig, P < 0.05). Piglets relocated to an enriched pen after weaning showed a greater growth in the 2 wk after weaning (barren 5.5 ± 0.2 kg/pig, enriched 6.2 ± 0.2 kg/pig, P < 0.0001), had a profoundly reduced diarrhea prevalence than piglets housed in barren pens after weaning (barren 2.4 ± 0.4 d, enriched 1.0 ± 0.3 d, P < 0.0001), and had a greater feed efficiency (barren 0.81 ± 0.03, enriched 0.85 ± 0.02, P < 0.05). Enrichment of the preweaning environment likely stimulates development of feeding behaviors and consequently increases feed intake immediately after weaning. Providing piglets with an enriched environment after weaning positively affected postweaning growth, feed efficiency, and incidence of diarrhea, which may be caused by decreased stress or increased gut health. Enrichment of the pre- and postweaning environment seems important in improving performance and health of newly weaned pigs.

Maternal presence and environmental enrichment affect food neophobia of piglets

Young omnivores show food neophobia in order to avoid the potential harmful effects of ingesting unfamiliar food items. We investigated whether the presence of the mother and an enriched rearing environment would reduce food neophobia in piglets. A mother may provide information on suitable food types to include in the diet, whereas an enriched environment may stimulate behavioural development and reduce reactivity towards novel stimuli (including food). Five barren-reared or enriched-reared piglets per litter were exposed to two novel food items in the presence, and the other five per litter in the absence, of the mother in a 7 min test. Maternal presence reduced food neophobia profoundly as reflected in a reduced latency to touching the food, a higher proportion of piglets sampling the two different food items and a higher intake. Latency to touch the food, however, was affected by maternal presence more strongly for barren-reared piglets than for enriched-reared piglets, and in the absence of the sow, consumption of one novel food type and time spent in the feeding area were higher for enriched-reared piglets. Environmental enrichment does have the potential to reduce food neophobia, but the presence of the mother during the encounter with novel food seems more efficient in decreasing food neophobia of piglets.

Social feeding decisions in horses (Equus caballus)

Like many other herbivores, in a natural environment equids feed on rather evenly distributed resources. However, the vegetation in their vast habitats constantly changes. If food is plentiful only little competition occurs over food, and in non-competitive situations domestic horses tend to return to the same feeding site until it is overgrazed. In contrast, they compete over limited food for which the social status of the individuals appears to be important. Especially in ruminants several studies have proved an influence of social organisations, rank, sex and the depletion of feeding sites on the feeding behaviour of individuals. However, it is not yet understood whether and how social aspects affect horses' feeding decisions. Curiosity about the influence of social rank on the horses' feeding decisions between two, equally with high-quality surplus food-filled buckets placed in different social feeding conditions, led us to create the test below. The observer horses were alternately tested with a dominant and a subordinate demonstrator placed in one of the three different positions. We conclude that domestic horses use social cognition and strategic decision making in order to decide where to feed in a social feeding situation. When possible they tend to return to the same, continuously supplied feeding site and switch to an "avoidance tendency" in the presence of dominant horses or when another horse is already feeding there. Thus, the social rank and the position of conspecifics affect the feeding strategy of horses.