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

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 […]

Effects of group composition on the grazing behaviour of herbivores

Animal behaviour is often a function of the animal’s physiological state. Groups of animals will often contain individuals with a range of physiological states and the grazing behaviour of herbivores is affected by their physiological state. This study compared the grazing decisions of animals in groups of single and mixed physiological states. Using a grazing […]

Group size and structure in western lowland gorillas (Gorilla gorilla gorilla) at Mbeli Bai, Republic of Congo

This paper describes the size and structure of western lowland gorilla groups visiting Mbeli Bai, a swampy forest clearing in northern Congo. An observation platform at the edge of the clearing was used over a 3-yr period, with gorillas visible for 1,681 hr. Data are presented on 14 groups and seven solitary males. Mean group […]

Factors influencing the behaviour and welfare of captive lion-tailed macaques in Indian zoos

A behavioural study was conducted on 47 lion-tailed macaques housed in 13 zoos across India. An ethogram was constructed and behavioural observations conducted using qualitative sampling ad libitum, focal animal sampling and instantaneous scans. Sampling was conducted only during the day when visitors were present at the macaque enclosures. Stereotypic pacing was the most commonly […]

Influence of indoor-cat group size and dominance rank on urinary cortisol levels

Domestic cats (Felis silvestris catus) are often housed indoors both singly and in groups. However, there is a lack of studies dealing with cat-cat relationships, group composition and effects of environmental parameters on the well-being of privately-owned cats. One way to index the effects of stressful situations is to measure glucocorticoid levels, as glucocorticoids are […]

The birth of an infant decreases group spacing in a zoo-housed lowland gorilla group (Gorilla gorilla gorilla)

Changes in group composition can alter the behavior of social animals such as gorillas. Although gorilla births are presumed to affect group spacing patterns, there is relatively little data about how these events affect gorilla group cohesion. We investigated how members of a western lowland gorilla group (n = 6) at Lincoln Park Zoo (Chicago, IL, USA) […]

Influence of Paddock Size on Social Relationships in Domestic Horses

ABSTRACTThe aim of this study was to explore whether the size of paddocks affected social interactions within a group of horses. Furthermore, the effects of the gender composition in groups on social behavior were investigated. The research was done in a horse-riding center. A total of 78 horses and ponies, forming 3 groups, were included […]