Observation Of Conspecifics Research Articles

Emulative learning of a two-step task in free-ranging domestic pigs

Previous research showed that young domestic pigs learn through observation of conspecifics by using social learning mechanisms like social facilitation, enhancement effects, and even object movement re-enactment. The latter suggests some form of emulative learning in which the observer learns about the object’s movements and affordances. As it remains unclear whether pigs need a social agent to learn about objects, we provided 36 free-ranging domestic pigs with varying degrees of social to non-social demonstrations on how to solve a two-step manipulative foraging task: observers watched either a conspecific or a human demonstrator, or self-moving objects ("ghost control"), or a ghost control accompanied by an inactive conspecific bystander. In addition, 22 subjects that were previously tested without any demonstrator were used as a non-observer control. To solve the task, the subjects had to first remove a plug from its recess to then be able to slide a cover to the side, which would lay open a food compartment. Observers interacted longer with the relevant objects (plugs) and were more successful in solving the task compared to non-observers. We found no differences with regard to success between the four observer groups, indicating that the pigs mainly learned about the apparatus rather than about the actions. As the only common feature of the different demonstrations was the movement of the plug and the cover, we conclude the observer pigs learned primarily by emulation, suggesting that social agents are not necessary for pigs when learning through observation.

Comparative study of stress responses, laterality and familiarity recognition between albino and pigmented fish

Oculocutaneous albinism is the result of a combination of homozygous recessive mutations that block the synthesis of the tyrosine and melatonin hormones. This disability is associated with physiological limitations, e.g., visual impairment expressed by lower visual acuity and movement perception, and eventually leads to acrophobia and/or photophobia, suggesting a potentially higher stress level associated with the behavioral responses of individuals with albinism to external stimuli compared to their pigmented conspecifics. However, in fish, differences in behavioral and/or physiological responses and stress levels between these phenotypes have been poorly documented. While acoustic perception of albino individuals is well known, the use of olfactory sensors for social communication, e.g., for the preference for familiar conspecifics, remains poorly understood. We performed two laboratory experiments with albino and pigmented European catfish Silurus glanis to observe: i) their behavioral and physiological responses to short-term stress induced by a combination of air exposure and novel environmental stressors and ii) their ability to use odor keys to recognize of familiar conspecifics and the influence of lateralization on this preference. In response to stress stimuli, albino fish showed higher movement activities and ventilatory frequencies and more often changed their swimming directions compared to their pigmented conspecifics. Blood plasma analysis showed significantly higher values of stress-, deprivation-, and emotional arousal-associated substances, e.g., glucose and lactate, as well as of substances released during intensive muscle activity of hyperventilation and tissue hypoxia, e.g., hemoglobin, mean corpuscular hemoglobin, erythrocytes, and neutrophil granulocytes. A preference test between environments with and without scented water showed the preference by both albino and pigmented catfish for environments with scent of familiar conspecifics, and both groups of fish displayed left-side lateralization associated with the observation of conspecifics and group coordination. The results tended to show higher physiological and behavioral responses of albinos to stress stimuli compared to the responses of their pigmented conspecifics, but the uses of olfactory sensors and lateralization were not differentiated between the two groups.

Clark's nutcrackers (Nucifraga columbiana) use a visual barrier for cache protection.

Previous work with corvids such as scrub jays (Aphelocoma californica) and ravens (Corvus corax) suggests that many social corvids alter their caching behavior when observed by conspecifics to protect their caches. We examined whether the Clark's nutcracker (Nucifraga columbiana), an asocial corvid, can utilize a barrier to conceal its caching activities from a conspecific observer. Nutcrackers were allowed to cache nuts in a visible or concealed location in either the presence or absence of an observer. Nutcrackers were also given experience of having their caches pilfered. The nutcrackers cached significantly more nuts in the concealed compared to a visible location when observed. Importantly, nutcrackers also recovered a larger percentage of their nuts 24 hr later from a visible cache location but when the observer was no longer present. The results extend recent work suggesting that relatively nonsocial corvids, similar to their more social relatives, also engage in multiple forms of cache protection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Social Learning in Horses-Fact or Fiction?

Prima facie, the acquisition of novel behaviors in animals through observation of conspecifics seems straightforward. There are, however, various mechanisms through which the behavior of animals can be altered from observing others. These mechanisms range from simple hard-wired contagious processes to genuine learning by observation, which differ fundamentally in cognitive complexity. They range from social facilitation and local enhancement to true social learning. The different learning mechanisms are the subject of this review, largely because research on learning by observation can be confounded by difficulties in interpretation owing to the looming possibility of associative learning infecting experimental results. While it is often assumed that horses are capable of acquiring new behavior through intra-species observation, research on social learning in horses includes a variety of studies some of which may overestimate the possession of higher mental abilities. Assuming such abilities in their absence can have welfare implications, e.g., isolating stereotypical horses on the assumption that these behaviors can be learned though observation by neighboring horses. This review summarizes the definitions and criteria for the various types of social transmission and social learning and reviews the current documentation for each type in horses with the aim of clarifying whether horses possess the ability to learn through true social learning. As social ungulates, horses evolved in open landscapes, exposed to predators and grazing most of the day. Being in close proximity to conspecifics may theoretically offer an opportunity to learn socially, however anti-predator vigilance and locating forage may not require the neural complexity of social learning. Given the significant energetic expense of brain tissue, it is likely that social facilitation and local enhancement may have been sufficient in the adaptation of equids to their niche. As a consequence, social learning abilities may be maladaptive in horses. Collectively, the review proposes a novel differentiation between social transmission (social facilitation, local, and stimulus enhancement) and social learning (goal emulation, imitation). Horses are undoubtedly sensitive to intra-species transfer of information but this transfer does not appear to satisfy the criteria for social learning, and thus there is no solid evidence for true social learning in horses.

Difficulties when using video playback to investigate social cognition in California scrub-jays (Aphelocoma californica).

Previous research has suggested that videos can be used to experimentally manipulate social stimuli. In the present study, we used the California scrub-jays’ cache protection strategies to assess whether video playback can be used to simulate conspecifics in a social context. In both the lab and the field, scrub-jays are known to exhibit a range of behaviours to protect their caches from potential pilferage by a conspecific, for example by hiding food in locations out of the observer’s view or by re-caching previously made caches once the observer has left. Here, we presented scrub-jays with videos of a conspecific observer as well as two non-social conditions during a caching period and assessed whether they would cache out of the observer’s “view” (Experiment 1) or would re-cache their caches once the observer was no longer present (Experiment 2). In contrast to previous studies using live observers, the scrub-jays’ caching and re-caching behaviour was not influenced by whether the observer was present or absent. These findings suggest that there might be limitations in using video playback of social agents to mimic real-life situations when investigating corvid decision making.

Clark’s nutcrackers (Nucifraga columbiana) are sensitive to distance, but not lighting when caching in the presence of a conspecific

We examined the caching behavior of the Clark’s nutcracker (Nucifraga columbiana), a relatively asocial corvid bird, during social and non-social conditions with conspecifics. Past work by Dally et al., (2004, 2005a) has found that the related but more social scrub jay (Aphelocoma californica) caches food in locations that are far away or that are more dimly illuminated when in the presence of an observer. Here, we used procedures comparable to those of Dally’s group to examine if the less social nutcracker is also sensitive to these same factors when caching in the presence of a conspecific. We found that nutcrackers cached nuts farther away, but showed no preference for caching in a dimly compared to a brightly illuminated area when in the presence of a conspecific observer. When comparing the measures of cache protection used in the past work with scrub jays the results are consistent with the social organization of these birds; that is, the less social nutcracker engaged in fewer cache protection behaviors than the more social scrub jays, However, we explore other possible explanations for our findings given the wider body of literature on corvid cache protection suggesting that nutcrackers and scrub jays may be more comparable.

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological factors.

What to copy: the key factor of observational learning in striped jack (Pseudocaranx dentex) juveniles

Animals in social environments can enhance their learning efficiency by observing the behaviour of others. Our previous study showed that learning efficiency of schooling fish increased through the observation of the behaviour of trained demonstrator conspecifics. The present study aimed to verify the key factor of observational learning by investigating what information is important for social transmission of feeding information. A striped jack (Pseudocaranx dentex) observer was provided with one of the five observation treatments: (a) pellets observation, where pellets were dropped near the aeration in an adjacent tank; (b) responding conspecific observation, where a trained conspecific demonstrator responded to the aeration without food in the adjacent tank; (c) foraging conspecific observation, where a conspecific demonstrator foraged near the aeration in the adjacent tank; (d) nearby pellets observation, where pellets were dropped in a transparent column near the aeration in the observer tank; and (e) foraging heterospecific observation, where a filefish (Stephanolepis cirrhifer) demonstrator foraged near the aeration in the adjacent tank. The response to the aeration in these observers was compared with that of controls who did not observe any behaviour. Only individuals who observed foraging conspecifics showed a response to the aeration after observing. These results suggest that observer fish acquire feeding information not through recognition of prey items or through imitation of the demonstrator, but through the vicarious reinforcement of a conspecific for foraging.

Responses of chimpanzees to cues of conspecific observation

Recent evidence has shown that humans are remarkably sensitive to artificial cues of conspecific observation when making decisions with potential social consequences. Whether similar effects are found in other great apes has not yet been investigated. We carried out two experiments in which individual chimpanzees, Pan troglodytes, took items of food from an array in the presence of either an image of a large conspecific face or a scrambled control image. In experiment 1 we compared three versions of the face image varying in size and the amount of the face displayed. In experiment 2 we compared a fourth variant of the image with more prominent coloured eyes displayed closer to the focal chimpanzee. The chimpanzees did not look at the face images significantly more than at the control images in either experiment. Although there were trends for some individuals in each experiment to be slower to take high-value food items in the face conditions, these were not consistent or robust. We suggest that the extreme human sensitivity to cues of potential conspecific observation may not be shared with chimpanzees.

The "Super Chimpanzee": The Ecological Dimensions of Rehabilitation of Orphan Chimpanzees in Guinea, West Africa.

Simple SummaryThis study examines relevant behavioral indicators of rehabilitation success of orphaned chimpanzees, victims of the bushmeat and pet trade, and contributes to identifying future release candidates. Results highlight the importance of bush-outings in the development of species-specific behaviors. Neither trauma upon arrival nor contact with human caretakers predicted dietary knowledge among rehabilitants at the Chimpanzee Conservation Centre where the study took place. The studied orphans demonstrated a relatively broad dietary knowledge. We attributed this result to the combined effect of the multiregional origins of residents and the learning opportunities available during bush-outings, which we termed the “Super Chimpanzee” theory.To date few studies, especially among non-human primates, have evaluated or monitored rehabilitation effectiveness and identified key species-specific behavioral indicators for release success. This four-months study aimed to identify behavioral indicators of rehabilitation success among ten infant and juvenile orphaned chimpanzees cared for in peer groups at the Centre for Conservation of Chimpanzees (CCC), Guinea, West Africa. Behavioral data focused on foraging skills and activity budget. During bush-outings, rehabilitants spent on average nearly a quarter of their activity budget foraging, resting or traveling, respectively. Neither age, sex, the level of abnormal behaviors demonstrated upon arrival nor human contact during bush-outings predicted individual dietary knowledge. However, individuals who spent more time arboreal demonstrated a greater dietary breadth than conspecifics who dwelled more terrestrially. Although our data failed to demonstrate a role of conspecific observation in dietary acquisition, we propose that the mingling of individuals from different geographical origins may act as a catalyst for acquiring new dietary knowledge, promoted by ecological opportunities offered during bush-outings. This “Super Chimpanzee” theory opens up new questions about cultural transmission and socially-biased learning among our closest living relatives and provides a novel outlook on rehabilitation in chimpanzees.

Post-weaning social isolation impairs observational fear conditioning

Many mammals can utilize social information to learn by observation of conspecifics (social learning). Social learning of fear is expected to be especially advantageous for survival. However, disruption of social development in early life can impair social cognition and might also be expected to disrupt social learning. Social isolation during a critical period of adolescence disrupts social development. The purpose of this study was to determine whether disruption of social development through post-weaning social isolation leads to impairments of social fear learning. Rats were reared in isolation or pair-housed from immediately post-weaning, for 3 weeks. Social fear learning in rats was acquired by observation of tone-footshock pairings administered to a conspecific. Isolation-reared rats displayed less conditioned freezing than pair-housed rats when tested the next day. This reduction of conditioned freezing was correlated with conspecific-oriented behaviors during conditioning, was measured despite similarities in demonstrator behaviors, and occurred despite a manipulation that equalized freezing during conditioning between the pair-housed and isolation-reared rats. The results could not be explained by abnormal sensitization to a repeated tone or deficits in freezing or direct fear conditioning. These results demonstrate that observational fear conditioning is impaired by social isolation, and provide a model to study impaired social affective learning. Impaired social cognition, manifested as inability to recognize or appropriately interpret social cues, is a symptom of several psychiatric disorders. Better understanding of the mechanisms of impaired social fear learning can lead to novel treatments for social cognition symptoms of psychiatric disorders.

Análisis de los procesos de aprendizaje social que afectan elecciones alimenticias y sexuales en animales

Normal 0 21 false false false ES-MX X-NONE X-NONE Social interactions can profoundly Influence the stimuli to which an individual animal is exposed and, consequently, can determine the direction in which learning by individuals proceeds. My laboratory has been examining a few of the many ways in which social influences can bias development of behavioral repertoires of animals. Here, I briefly review our work of the last 30 years on social effects on the food choices of Norway rats and mate preferences of Japanese quail. I show that both the foods that rats ingest and the members of the opposite sex that quail select as sex partners can be profoundly biased by interaction with or observation of conspecifics and analyze behavioral processes that support social learning in these two model systems.

Chickadees are selfish group members when it comes to food caching

Many food-caching animals live in groups and cache pilferage may be one of the negative consequences of social living. Several hypotheses have been proposed to suggest that individuals may benefit from caching even when cache pilferage is high if all individuals can cache and pilfer equally. Stable groups may hypothetically support the evolution of such "reciprocal pilfering" because all group members may potentially have numerous opportunities to pilfer each other's caches. If that were the case, then we would expect animals cache openly in front of their group members, but to avoid caching in direct view of unknown conspecifics. We tested this hypothesis by allowing mountain chickadees (Poecile gambeli) to cache food in three experimental conditions: (1) with a familiar observer from the same group and with an unfamiliar conspecific observer present; (2) with a familiar observer from the same group only, and (3) without any observers. When presented with both a familiar and an unfamiliar observer, the caching chickadees treated both observers equally by choosing caching sites that were both farther away and out of sight of both observers. When only the familiar observer was present, chickadees shifted their choice of caching sites to the surfaces both away from and out of sight of the observer. When no observers were present, all available caching sites were used equally. Our results thus do not support the reciprocal cache sharing hypothesis and suggest that chickadees try to minimize cache pilferage from both familiar group members and unfamiliar conspecifics.

Lateralization of social learning in the domestic chick, Gallus gallus domesticus: learning to avoid

Social learning occurs through the observation of conspecifics performing biologically relevant behaviours. Like other forms of learning, aptitude for such tasks may be influenced by cerebral lateralization. Social recognition is subject to lateralization and it seems highly likely that any lateralization effect would be transposed onto a social-learning situation. We used a social version of a passive avoidance task in which one chick (the demonstrator) pecked at a red bead while another chick (the observer) viewed the demonstrator's response. This bead was either coated in the bitter-tasting substance methylanthranilate (MeA) or was left dry. Thirty minutes later both chicks were presented with a similar, dry, bead to determine whether learning had taken place. Experiment 1 showed that chicks were able to learn, by observation only, not to peck the bead when it had been coated in MeA at training. Experiment 2 demonstrated a role of lateralization in performing the task; specifically, male observer chicks trained binocularly but tested monocularly had a poorer performance in this task with the left hemisphere than with the right. In experiment 3, we both trained and tested chicks monocularly. This time there was no difference between left-eyed and right-eyed chicks, suggesting a spontaneous bias for encoding relevant information available at training in the right hemisphere. In conclusion, chicks are able to avoid pecking just by observing a conspecific. The social learning appears to be lateralized to the right hemisphere in male chicks, females showing no bias in lateralization.

The development of feeding behaviour in wild western lowland gorillas (Gorilla gorilla gorilla)

Before being weaned, young primates must learn which plant species are suitable to eat, and how to process and combine them to meet their nutritional needs. This study provides a detailed investigation of the development of feeding behaviour in a wild population of western lowland gorillas observed in a bai habitat. The behaviour of 56 known immature individuals aged between 0 and 8 years was recorded at Mbeli Bai, Republic of Congo, using focal, scan and all-occurrence sampling over a period of 16 months. Results indicated that independent feeding skills were acquired by the end of infancy and did not undergo significant change beyond this point. However, suckling continued into the juvenile period, suggesting that some continued investment by the mother was necessary until the strength and skills of immatures developed, perhaps to enable self-sufficiency through periods of succulent fruit (assumed to be the most suitable weaning food) scarcity. This was supported by observations of an increase in feeding-related behaviour with age, particularly during infancy. Additionally, age-related differences in the species and plant parts selected by different age classes, as well as in levels of food processing, were apparent. Play feeding, suggested to be a precursor to independent feeding, was most prevalent in infancy, decreasing as feeding skills developed. Thus, it would appear, given that food transfer also occurs (Nowell & Fletcher, 2006), that feeding skills in western lowland gorillas are learned by a combination of exposure to and manipulation of food items, and probably also through the observation of conspecifics. Observations in a forest habitat are needed to improve our understanding of feeding development in this subspecies.

Learning by observation in rhesus monkeys

Habit memory provides us with a vast repertoire of learned rules, including stimulus-reward associations, that ensures fast and adapted decision making in daily life. Because we share this ability with monkeys, lesion and recording studies in rhesus macaques have played a key role in understanding the neural bases of individual trial-and-error habit learning. Humans, however, can learn new rules at a lower cost via observation of conspecifics. The neural properties underlying this more ecological form of habit learning remain unexplored, and it is unclear whether the rhesus macaque can be a useful model in this endeavor. We addressed this issue by testing four monkeys from the same social group in their usual semi-natural habitat using a well-established marker of habit memory, concurrent discrimination learning. Each monkey learned 24 lists of 10 object-reward associations each. For one list out of two, monkeys could observe the testing session of another member of the group prior to being tested with the same list themselves. Learning was faster for these lists than for those learned solely by trial-and-error. Errors to criterion (9/10 correct responses) were reduced by 39%, and faultless performance could be achieved for up to 5 of the 10 pairs. These data demonstrate that rhesus macaques spontaneously observe a conspecific learning new stimulus-reward associations, and substantially benefit from this observation. They ascertain that the neural underpinnings of socially-mediated forms of habit learning can be explored using the powerful tools of monkey research, including neurophysiological recordings.

A demonstration of observational learning in rats using a bidirectional control.

Hungry rats observed a conspecific demonstrator pushing a single manipulandum, a joystick, to the right or to the left for food reward and were then allowed access to the joystick from a different orientation. The effects of right-pushing vs left-pushing observation experience on (1) response acquisition, (2) reversal of a left-right discrimination, and (3) responding in extinction, were examined. Rats that had observed left-pushing made more left responses during acquisition than rats that had observed right-pushing, and rats that had observed demonstrators pushing in the direction that had previously been reinforced took longer to reach criterion reversal and made more responses in extinction than rats that had observed demonstrators pushing in the opposite direction to that previously reinforced. These results provide evidence that rats are capable of learning a response, or a response-reinforcer contingency, through conspecific observation.

Can Captive-Bred Varecia variegata variegata Adapt to a Natural Diet on Release to the Wild?

We compared the diets of 3 groups of released captive-bred Varecia variegata variegata (RG1, RG2, RG3) in the Betampona Reserve to that recorded for a resident wild group, between 1998 and 2001. We investigated whether the released captive-bred Varecia, from differing captive backgrounds, could cope with seasonal changes in climate and consequently food availability, finding sufficient food to meet their nutritional requirements, and dietary choices and selection. We collected data on diet, including plant part, family, genus and, if known, species. In addition, we collected data on seasonal variation in dietary composition. Dietary overlap is significant at the familial level between RG1/RG3 and the wild group. There is some dietary overlap between RG2 and the wild group, but it is not significant. In general, RG1 and RG3 more closely followed the dietary choices and seasonal changes in diet exhibited by the wild group. We conclude that Varecia raised in free-ranging environments are better adapted to meet their nutritional requirements in the wild than those raised in cages are. However, even they struggle to deal with seasonal climatic changes and consequent changes in food availability. We suggest that future re-introduction efforts for primates include attempts to integrate released individuals rapidly into wild groups so that they can learn to cope with a seasonal environment through direct observation of wild conspecifics.

Testing for imitative and nonimitative social learning in the budgerigar using a two-object/two-action test

Male and female juvenile budgerigars, Melopsittacus undulatus, were allowed to observe a conspecific demonstrator using its beak to remove one of two distinctively coloured objects (i.e. a blue and a black stopper) from a hole in the lid of a box and eating seed from within. Both objects could be removed by either pulling up or pushing down. When subsequently allowed access to both stoppers, and rewarded with food for all removal responses, regardless of the object to which they were made and their direction, observer birds removed both stoppers in the same direction as their demonstrator. This effect was present on the first occasion when observers removed a stopper, and persisted over at least 24 trials. Female observers made more removal responses than males, but conspecific observation had equivalent effects on direction of responding in males and females. All observers tended to approach the same object as their demonstrator when the objects were discriminable using both spatial and colour cues, but not when they differed in colour alone. Contrary to previous findings, these results suggest that robust behavioural matching effects can be obtained in budgerigars, and that these birds are capable of motor imitation or emulation. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

Ultrasonic vocalization by female mice in the presence of a conspecific carrying food cues

In female mice, Mus domesticus, reunion with a same-sex conspecific is associated with intense ultrasonic vocalization. We examined whether the palatability of a familiar food eaten by a demonstrator mouse and the motivational state of the conspecific observer could modulate the number of ultrasonic calls uttered during female–female interaction in NMRI mice. A pilot study indicated that these calls were uttered almost exclusively by the observer member of the pair. Observers were either food deprived or not deprived and demonstrators were offered either no food, a palatable diet or an unpalatable diet. We monitored both the number of ultrasounds (range 65–75kHz) uttered and a series of behavioural parameters during the first 3min of social interaction after 24h of separation. Observers investigated the nose area of demonstrators fed on the unpalatable diet more than the same area of demonstrators not given food. No differences were found in demonstrators’ behaviour. Ultrasonic calls were given immediately after female–female reunion and were affected by both the motivational state of the observer and the salience of the information carried by the conspecific. These results suggest that the motivational state of the observer affects ultrasonic calling towards a demonstrator conspecific. Nondeprived animals produced more calls towards demonstrators fed on palatable food, whereas food-deprived subjects vocalized more to fed conspecifics, independently of the palatability of the food eaten by the demonstrator. We suggest that ultrasonic vocalization in female mice can facilitate proximity with a conspecific and the number of these calls is modulated by the salience of the information carried by the companion.