Dataset Information

Does group size matter? Captive chimpanzee (Pan troglodytes) behavior as a function of group size and composition.

ABSTRACT: The National Institutes of Health and the Association of Zoos and Aquariums recommend that captive chimpanzees be housed in multi-male, multi-female, age-diverse groups of no less than seven individuals. These recommendations are rooted in the idea that captive chimpanzee groups should be modeled after free-ranging, wild, fission-fusion chimpanzee societies. However, captive chimpanzees do not face the environmental pressures faced by wild chimpanzees, including food scarcity, inter-group competition, and predation. As such, it has been posited that wild, natural conditions may not be the most relevant metric for defining optimal captive chimpanzee group sizes and compositions. Additionally, captive housing poses a set of restrictions on group sizes and compositions, including the need to balance large, multi-male groups with space per animal limitations and intra-group aggression. In the present study, we examined the behavioral effects of group size, within-group age range, and percentage of males in the group. We collected 713?hr of focal animal samples across 120 captive chimpanzees housed in social groups of 4-10 individuals using a 58-behavior ethogram. Chimpanzees housed in groups with a large age range exhibited less inactivity and more locomotion than chimpanzees housed in groups with smaller age ranges. Additionally, chimpanzees in groups of ?7 with less than half males showed the highest levels of locomotion. Lastly, chimpanzees in groups of ?7 with at least half males showed the highest levels of affiliation. There were no other significant differences in behavior as a function of these variables or their interactions. These findings lend some support to the existing group size and composition recommendations, providing empirical evidence that there may be certain advantages to housing captive chimpanzees in larger groups with a more diverse age range and/or more males. These results also have practical implications for behavioral management programs across captive settings.

SUBMITTER: Neal Webb SJ

PROVIDER: S-EPMC6472487 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Does group size matter? Captive chimpanzee (Pan troglodytes) behavior as a function of group size and composition.

Neal Webb Sarah J SJ Hau Jann J Schapiro Steven J SJ

American journal of primatology 20190108 1

The National Institutes of Health and the Association of Zoos and Aquariums recommend that captive chimpanzees be housed in multi-male, multi-female, age-diverse groups of no less than seven individuals. These recommendations are rooted in the idea that captive chimpanzee groups should be modeled after free-ranging, wild, fission-fusion chimpanzee societies. However, captive chimpanzees do not face the environmental pressures faced by wild chimpanzees, including food scarcity, inter-group compet ...[more]

PMID: 30620093

Similar Datasets

Project description:Space per animal, or animal density, and enclosure type are important elements of functionally appropriate captive environments (FACEs) for chimpanzees. The National Institutes of Health (NIH) recommends that captive chimpanzees be maintained in areas of >250 ft2 /animal. Several studies have investigated chimpanzee behavior in relation to space per animal, but only two studies have examined these variables while attempting to hold environmental complexity constant. Both have found few, if any, significant differences in behavior associated with increased space per animal. The NIH does not provide recommendations pertaining to enclosure type. Although Primadomes™ and corrals are considered acceptable FACE housing, no studies have investigated chimpanzee behavior in relation to these two common types of enclosures. We examined the NIH space per animal recommendation, and the effects of enclosure type, while maintaining similar levels of environmental complexity. We used focal animal observations to record the behavior of 22 chimpanzees in three social groups following within-facility housing transfers. Chimpanzees that were moved from an area with space below the NIH recommendation to the same type of enclosure with space above the recommendation (dome to double dome) exhibited significantly more locomotion and behavioral diversity post-transfer. Chimpanzees that were moved from an area with space below the recommendation to a different type of enclosure with space above the recommendation (dome to corral) exhibited significant increases in foraging and behavioral diversity, and a decrease in rough scratching. Lastly, chimpanzees that were moved from an area above the recommendation to a different enclosure type with space equal to the recommendation (corral to double dome) exhibited an increase in behavioral diversity. These results add to the body of literature that addresses the concept of specific minimum space requirements per chimpanzee, and highlight the need for more empirical investigation of the relationship between space per chimpanzee, behavior, and welfare.

Project description:Voluntary participation in behavioural studies offers several scientific, management, and welfare benefits to non-human primates (NHPs). Aside from the scientific benefit of increased understanding of NHP cognition, sociality, and behaviour derived from noninvasive behavioural studies, participation itself has the potential to provide functional simulations of natural behaviours, enrichment opportunities, and increased control over the captive environment, all of which enhance welfare. Despite a developing consensus that voluntary participation offers these welfare enhancements, little research has empirically investigated the ways that participation in behavioural studies may affect welfare. In the current study, we investigated potential relationships between captive chimpanzee welfare and long-term, repeated voluntary participation in noninvasive behavioural studies. We collected behavioural data on 118 chimpanzees at the National Center for Chimpanzee Care (NCCC) in Bastrop, Texas, USA between 2016 and 2018 using 15-minute focal animal samples. Additionally, we collected information on 41 behavioural studies conducted between 2010 and 2018 with the NCCC chimpanzees that involved exposure to a stimulus or manipulation. The total number of behavioural studies in which chimpanzees had participated over the approximately eight-year period was then examined in relation to levels of behavioural diversity, abnormal behaviour, rough scratching, inactivity, and locomotion using a series of regression analyses that controlled for rearing status and age of the chimpanzee at the time of data collection. Analyses revealed significant, positive relationships between the total number of studies in which chimpanzees participated and 1) behavioural diversity scores, R2 adj = .21, F(3,114) = 11.25, p < 0.001; and 2) rough scratching, R2 adj = .11, F(3,114) = 6.01, p = 0.001. The positive relationship between behavioural diversity scores and the total number of studies in which chimpanzees participated seems unsurprising, although we cannot draw conclusions about the directionality of this relationship. The result that rough scratching and the total number of studies in which chimpanzees participated were positively correlated is unexpected. However, rough scratching made up less than 1% of all activity in the current study, and as such, this result may not be biologically meaningful. These findings suggest that participation in behavioural studies is not likely to be detrimental to chimpanzee well-being, and may even be beneficial. Data such as these, which empirically investigate existing recommendations can help inform decisions pertaining to the participation of chimpanzees in behavioural research.

Project description:Across vertebrates, species with intense male mating competition and high levels of sexual dimorphism in body size generally exhibit dimorphism in age-specific fertility. Compared with females, males show later ages at first reproduction and earlier reproductive senescence because they take longer to attain adult body size and musculature, and maintain peak condition for a limited time. This normally yields a shorter male duration of effective breeding, but this reduction might be attenuated in species that frequently use coalitionary aggression. Here, we present comparative genetic and demographic data on chimpanzees from three long-term study communities (Kanyawara: Kibale National Park, Uganda; Mitumba and Kasekela: Gombe National Park, Tanzania), comprising 581 male risk years and 112 infants, to characterize male age-specific fertility. For comparison, we update estimates from female chimpanzees in the same sites and append a sample of human foragers (the Tanzanian Hadza). Consistent with the idea that aggressive mating competition favors youth, chimpanzee males attained a higher maximum fertility than females, followed by a steeper decline with age. Males did not show a delay in reproduction compared with females, however, as adolescents in both sites successfully reproduced by targeting young, subfecund females, who were less attractive to adults. Gombe males showed earlier reproductive senescence and a shorter duration of effective breeding than Gombe females. By contrast, older males in Kanyawara generally continued to reproduce, apparently by forming coalitions with the alpha. Hadza foragers showed a distinct pattern of sexual dimorphism in age-specific fertility as, compared with women, men gained conceptions later but continued reproducing longer. In sum, both humans and chimpanzees showed sexual dimorphism in age-specific fertility that deviated from predictions drawn from primates with more extreme body size dimorphism, suggesting altered dynamics of male-male competition in the two lineages. In both species, coalitions appear important for extending male reproductive careers.

Dataset Information

Does group size matter? Captive chimpanzee (Pan troglodytes) behavior as a function of group size and composition.

Publications

Does group size matter? Captive chimpanzee (Pan troglodytes) behavior as a function of group size and composition.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets