Captive Family Groups Research Articles

Behavior in a captive family group of Siamese Crocodiles (Crocodylus siamensis) at the Madras Crocodile Bank Trust near Chennai, India

Behavior in a captive family group of Siamese Crocodiles (Crocodylus siamensis) at the Madras Crocodile Bank Trust near Chennai, India

Learning strategies and long-term memory in Asian short-clawed otters (Aonyx cinereus).

Social learning, where information is acquired from others, is taxonomically widespread. There is growing evidence that animals selectively employ ‘social learning strategies', which determine e.g. when to copy others instead of learning asocially and whom to copy. Furthermore, once animals have acquired new information, e.g. regarding profitable resources, it is beneficial for them to commit it to long-term memory (LTM), especially if it allows access to profitable resources in the future. Research into social learning strategies and LTM has covered a wide range of taxa. However, otters (subfamily Lutrinae), popular in zoos due to their social nature and playfulness, remained neglected until a recent study provided evidence of social learning in captive smooth-coated otters (Lutrogale perspicillata), but not in Asian short-clawed otters (Aonyx cinereus). We investigated Asian short-clawed otters' learning strategies and LTM performance in a foraging context. We presented novel extractive foraging tasks twice to captive family groups and used network-based diffusion analysis to provide evidence of a capacity for social learning and LTM in this species. A major cause of wild Asian short-clawed otter declines is prey scarcity. Furthering our understanding of how they learn about and remember novel food sources could inform key conservation strategies.

Post-conflict opponent affiliation reduces victim re-aggression in a family group of captive arctic wolves (Canis lupus arctos).

Post-conflict affiliative interactions have been widely investigated in primates but not extensively in other species. Using the Post Conflict-Matched Control (PC-MC) comparison method, this study investigated the patterns of post-conflict opponent affiliation (POA) of a captive family group of 19 arctic wolves (Canis lupus arctos), investigating the correlation with various factors. We found that POAs occurred mainly in the non-feeding context and more often when the victim was dominant and the aggressor subordinate. Furthermore, POAs were more likely to have been initiated by the victim than the aggressor. Victims’ stress related behaviours occurred more in PC than MC periods, and more after high vs. low intensity aggressions but they were not more likely to occur after conflicts between wolves with a stronger social bond and POAs did not reduce their rate of occurrence. Our results showed that re-aggression was twice less frequent when a friendly interaction occurred between the aggressor and the victim, and consistent with this, victims engaged in POAs more often than the aggressor. Overall, our results support the hypothesis that POAs in wolves may have been selected for as a mechanism to avoid conflict escalation, which could lead to social disruption and hence jeopardize cooperative activities. The high relatedness among individuals in the pack and the greater dependence of all members on cooperation in breeding and hunting may reduce the importance of ‘relationship quality’ as a mediating factor of POAs, although dominance relationships, which are directly linked to the risks of further conflicts, do play an important role.

Play fighting in Visayan warty pigs (Sus cebifrons): insights on restraint and reciprocity in the maintenance of play

Restraint is thought to be essential to enable the reciprocity needed for play fighting to remain playful. Descriptions of playing in pigs suggest that they do not exhibit restraint. Analysis of videotaped sequences of play fighting in captive family groups of warty pigs was used to test three hypotheses about restraint and reciprocity. Hypothesis 1 asserts that the lack of restraint arises from neither participant handicapping its actions in favour of its opponent: this was supported. Hypothesis 2 asserts that the winner of a contest will show restraint by not prosecuting further attack: this was not supported. However, the winner did refrain from attacking if the loser signalled submission. Hypothesis 3 asserts that restraint by the winner will allow reciprocal attacks by the loser — this was supported. The dissociation of restraint and reciprocity evident in the pigs offers some new insights into the evolution of play fighting.

Long-term fidelity of foraging techniques in common marmosets (Callithrix jacchus).

The formation of behavioral traditions has been considered as one of the main building blocks of culture. Numerous studies on social learning in different animal species provide evidence for their capability of successful transmission of information. However, questions concerning the memory and maintenance of this information have received comparably little attention. After the innovation and initial spread of a novel behavior, the behavior should stabilize and be maintained over time. Otherwise, the behavioral pattern might collapse and no tradition formation would be possible. The aim of this study was to investigate long-term preferences in a two-action manipulation task in common marmosets (Callithrix jacchus). Three captive family groups (23 individuals in total) were trained on one of two possible techniques to open a wooden box and gain access to a food reward, by either pulling or pushing a flap door. The training phase took place in a family group setting, while the test phase was conducted individually. Although the subjects could experience the alternative technique during the test sessions, the majority preferentially used the technique learned in the group setting. Moreover, the subjects were re-tested six times over a period of more than four years, in order to examine the fidelity of their preferences. The longest break without exposure the task lasted for 3.5 years. In all tests, the marmosets showed a similar preference as in the first test block shortly after the training. To our knowledge, this is the first lab study that experimentally demonstrates memory and fidelity of experimentally seeded information in a manipulation task over a time period of several years, supporting the assumption that socially learned foraging techniques can lead to relatively stable behavioral traditions.

Monogamy and family life in callitrichid monkeys: deviations, social dynamics and captive management

Marmosets, tamarins and Goeldi's monkeys Callimico goeldii (Callitrichidae) are well represented in zoos. Owing to their small size, their attractive appearance and their social organization in family groups along with extensive alloparental care, these clawed New World monkeys make fine contributions to any primate collection. In the wild, callitrichids became famous for their so‐called ‘social flexibility’, whereas in captivity they can only be kept in heterosexual pairs or grown family groups. This contradiction is addressed in this article. Based on proximate aspects of behaviour, it is concluded that monogamy is the modal social grouping of any callitrichid taxon. In captive family groups of callitrichids, the underlying behavioural mechanisms that ensure the social and sexual integrity of that taxon‐specific pattern give rise to the kind of social dynamics that zoo personnel have to cope with at regular intervals; that is, marked intra‐group aggression and expulsion of group members. In summary, the overall behavioural theme of naturally grown groups of marmosets, tamarins and Goeldi's monkeys seems to be that their members are torn between cooperation and competition, resulting in occasional periods of social instability.

A Longitudinal Study of the Sociosexual Dynamics in a Captive Family Group of Wolves: The University of Connecticut Wolf Project

An interest in the role of the social environment on the evolution of behavior led Professor Benson Ginsburg to studies of wolf social behavior. He initiated the University of Connecticut wolf project with a family group of wolves housed in a protected enclosure in an isolated area of campus. One aim of this project was to conduct a longitudinal study of a family group of wolves in order to understand the proximate behavioral mechanisms underlying mating dynamics with a degree of control and opportunistic observation that could not be achieved through field studies. The development of social relationships and the dynamics of mating were observed for 9years. As in nature, agonistic relationships strongly influenced reproductive success, successful breeding was limited to a single pair each season, and the behavioral dynamics included status transitions with breeder rotations. Our work, when combined with the results of other captive wolf studies, has contributed valuable information to the general understanding of wolf social behavior, especially regarding the proximate behavior patterns underlying group social interactions and reproduction. This understanding has broadened perspectives on the dynamic interplay between social behavior and evolutionary processes.

When play is a family business: adult play, hierarchy, and possible stress reduction in common marmosets

Easy to recognize but not easy to define, animal play is a baffling behavior because it has no obvious immediate benefits for the performers. However, the absence of immediate advantages, if true, would leave adult play (costly but maintained by evolution, spanning lemurs to Homo sapiens) unexplained. Although a commonly held view maintains that play is limited by stress, an emergent hypothesis states that play can regulate stress in the short term. Here we explored this hypothesis in a captive family group of New World monkeys, Callithrix jacchus (common marmoset). We observed six subjects and gathered data on aggressive, play, and scratching behavior via focal (6h/individual) and all occurrences sampling (115h). We found that play levels were highest during pre-feeding, the period of maximum anxiety due to the forthcoming competition over food. Scratching (the most reliable indicator of stress in primates) and play showed opposite trends along hierarchy, with dominants scratching more and playing less than subordinates. Finally, scratching decreased after play, whereas play appeared to be unrelated to previous scratching events, symptoms of a potential stressful state. In conclusion, both play timing and hierarchical distribution indicate that play limits stress, more than vice versa, at least in the short term.

Fecal androgen levels in common marmoset (Callithrix jacchus) males living in captive family groups

In captive common marmoset groups, the reproductive inhibition observed in subordinate female seems to be a result of olfactory, visual and behavioral cues from the dominant female. However, few studies have examined the relationship among adult males living in the same social group. These studies have shown that reproductive failure among peer males seems to be based on hormonal and behavioral mechanisms. New insights on sexual strategies in primates have been shown using fecal steroids, but so far no information is available for common marmoset males. In the present study, we evaluated the influence of light-dark cycle, age and reproductive condition on the profile of fecal androgens in males living in the same family group. Feces were collected from six fathers and six sons for androgen determination during the light phase of the 24-h cycle for eight days randomly distributed over a 4-week period. Androgen levels were determined by enzyme immunoassay technique. Adult sons showed higher androgen levels (166.97 +/- 22.95 ng/g) than fathers (80.69 +/- 44.38 ng/g) and juveniles (49.06 +/- 23.15 ng/g; P < 0.05). No diurnal variation (P > 0.05) in fecal androgen profile was observed in adults or juveniles. No indication of androgen-mediated social competition between fathers and adult sons was demonstrable. These results provide basic information on fecal androgen profile useful to investigate the socioendocrinology of free-ranging common marmoset males and verify that, in contrast to daughters, the reproductive suppression of sons is not based on physiological inhibition of their gonads.

Helping Behaviour in Captive Pileated Gibbons (Hylobates pileatus)

Helping behaviour, defined as the care of offspring by individuals other than their parents, appears to be particularly common in monogamous mammals [1]. Although all gibbon species typically live in monogamous family groups, there are extremely few observations of helping behaviour (usually in the form of carrying younger siblings) [2]. This paper reports on helping behaviour observed in a captive family group of pileated gibbons (Hylobates pileatus) at the Zurich Zoo. These observations were made during a study on the behavioural development of an infant pileated gibbon reared in its natal group during its first year of life [3].

Differences in winter activity, courtship, and social behavior of two captive family groups of Mexican wolves Canis lupus baileyi

The purpose of this study was to determine differences in activity patterns and social behavior of two groups of endangered Mexican wolves maintained at two quite different facilities and to determine some of the variables that should be considered when making specific behavioral comparisons among wolves in this binational captive breeding program. Quantitative measurements of an Activity Index and social behaviors were obtained for three individuals in each pack. Within each age/sex category, activity, aggression, and play were more frequent in the pack at a zoo facility, compared to the pack at a field station facility. Frequency of courtship interactions and scent marking were significantly higher in the field station pack. The packs were similar in the frequency of active submission, but differed significantly in the pattern of this behavior. Given the large number of interacting variables and small number of individuals in this study, we recommend caution in generalizing results to other packs or facilities. Zoo Biol 16:435–443, 1997. © 1997 Wiley-Liss, Inc.

Differences in winter activity, courtship, and social behavior of two captive family groups of Mexican wolves(Canis lupus baileyi)

The purpose of this study was to determine differences in activity patterns and social behavior of two groups of endangered Mexican wolves maintained at two quite different facilities and to determine some of the variables that should be considered when making specific behavioral comparisons among wolves in this binational captive breeding program. Quantitative measurements of an Activity Index and social behaviors were obtained for three individuals in each pack. Within each age/sex category, activity, aggression, and play were more frequent in the pack at a zoo facility, compared to the pack at a field station facility. Frequency of courtship interactions and scent marking were significantly higher in the field station pack. The packs were similar in the frequency of active submission, but differed significantly in the pattern of this behavior. Given the large number of interacting variables and small number of individuals in this study, we recommend caution in generalizing results to other packs or facilities. Zoo Biol 16:435–443, 1997. © 1997 Wiley-Liss, Inc.

Group harmony in gibbons: Comparison between white-handed gibbon (Hylobates lar) and siamang (H. syndactylus)

The siamang (Hylobates syndactylus) is exceptional among gibbons in that its area of distribution almost completely overlaps those of other gibbons, namely the white-handed gibbon (H. lar) and the agile gibbon (H. agilis) of the lar group. The siamang has almost twice the body weight of the gibbons of the lar group (ca. 11 kg vs. 5–6 kg), and it has been suggested that distinct ecological and behavioural differences exist between the siamang and its two sympatric species. The siamang has been claimed to differ from the white-handed gibbon “in the closer integration and greater harmony of group life” (Chivers, 1976, p. 132). However, few quantitative data exist to support this hypothesis. In the present study, intra-group interactions in captive family groups of white-handed gibbons and siamangs (two groups of each species) were recorded by focal-animal sampling. These data failed to show a consistent association between species and most of the behavioural patterns recorded, such as frequency of aggression, percentage of successful food transfer, frequency of social grooming bouts, and duration of social grooming/animal/hr. A significant difference was found for only two of the variables: Individual siamangs in this study showed longer grooming bout durations, and made fewer food transfer attempts than lar individuals. Only the first of these two differences is consistent with the hypothesis mentioned above, whereas the lower frequency of food transfer attempts in siamangs is the opposite of what should be expected under the hypothesis. On the other hand, two of these behavioural patterns showed a significant correlation with the parameters group size and individual age: Both individuals in larger groups and younger individuals tended to show shorter grooming bouts and a smaller proportion of successful food transfers. Our findings indicate that social cohesion within these gibbon groups may be much more flexible according to and depending on social or ecological influences and less rigidly linked to specific gibbon taxa than previously assumed. A considerably larger number of gibbon groups would have to be compared to provide reliable evidence for or against species-specific differences in group cohesion. Another finding of this study—a positive correlation between the frequency of aggression and grooming—is discussed in the light of the functional interpretations commonly attributed to allogrooming behaviour in primates.

The fertility of daughters in common marmoset (Callithrix jacchus jacchus) family groups

Observations previously made in the field of inter-group mating raised questions concerning the fertility of daughters in family groups and about possible competition between mothers and daughters. To test whether daughters in captive family groups could become pregnant, daughters from four groups were placed with a strange male for a period of 30 min, twice a week for eight weeks. No changes were observed in the mother/daughter interactions during the time in which the daughters were allowed contact with the strange male. Two of the daughters showed signs of ovulation and the male only copulated with these animals. One daughter became pregnant, but it was aggression with her siblings rather than her mother which necessitated removing her from her family group.

DNA 'fingerprinting' of captive family groups of common marmosets (Callithrix jacchus).

DNA 'fingerprinting' of captive family groups of common marmosets (Callithrix jacchus).

High motivation toward food increases food-sharing in cotton-top tamarins.

In order to explore whether or not adult motivation influences transfer of food to infants in cotton-top tamarins (Saguinus oedipus oedipus), 2 experiments were carried out with 3 large captive family groups. Examination of (a) natural changes in food motivation during feeding, and (b) elevated motivation toward food by giving highly preferred items, showed that the adult monkeys shared food more when their own level of motivation was high. This suggests that food-transfer is not merely a consequence of adult satiation, but that matching sharing with high adult motivation is a mechanism which ensures that infants receive ample food, the best items, and also rare items of high quality.

Infant-caregiver interactions in common marmosets (Callithrix jacchus): Consequences of rejections and rub-offs of infants by caregivers

Interactions between common marmoset infants (Callithrix jacchus) and their fathers, mothers, older siblings and twins were examined in captive family groups. The aim was to record infants' behaviour after being rejected in their attempts to get on to caregivers and after being rubbed off by caregivers who had been carrying them.

Social development during the first twenty weeks in the cotton-top tamarin ( Saguinus o. oedipus)

Fourteen infant cotton-top tamarins from five captive family groups were studied during the first 20 weeks of life. We examined the roles of parents and of siblings of different ages as caregivers and as social companions for the infants, as well as the effects of group composition and group size on these roles. Parents and adult siblings played similar active roles in infant caregiving during the first few weeks after birth, with males showing a greater involvement than females. In groups without other offspring the two parents showed equal infant caregiving behaviour, whreas fathers carried more than mothers did in groups with offspring present. Although infants received more caregiving from males, they showed a preference for contact and proximity with their mothers. No sex differences were found in infant behaviour or in the direction of behaviour by caregivers toward infants. Twins showed greater amounts of both social and solitary play in weeks 15–20 than did singletons, and there was no effect of the number of older siblings on the amount of play shown by an infant.

Interactions between parents and infants, and the development of independence in the common marmoset ( Callithrix jacchus)

Detailed observations were made of the parent-infant interactions of five adult pairs and 31 infant common marmosets ( Callithrix jachus), housed in captive family groups. Records of parental measures were taken up to 4 months old and comparisons made between infants in similar social situations. These comparisons investigate sex differences, birth-order variations, those between singleton and twin infants, parental variation and the proportion of time that older siblings carry infants. Correlations between the measures reveal that both parents are responsible for promoting and regulating increasing infant independence. In the discussion, comparisons are made with other parent-infant studies and problems of the adaptiveness of the Callitrichid social system considered.

Food sharing among captive gibbons (Hylobates lar)

A captive family group of gibbons engages in food sharing during consistently patterned sequences of behaviors in which begging gestures are employed. The predominant occurrence of the behavior involves the juvenile female begging from her older, adult sister who acted as her surrogate mother. An examination of the variables potentially affecting the behavior, such as hunger, the availability and accessibility of preferred foods, the inability to forage individually, and the social relationships between members of the family, indicates that food sharing may assist the young in acquiring appropriate food habits, supplement their foraging capabilities, and may serve to reinforce the social bonds betweeen adult and imma- ture members of the family group.