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 […]

A note on swimming group size in captive African penguins (Spheniscus demersus) in relation to weather conditions

The swimming group size of captive African penguins (Spheniscus demersus) was studied in relation to weather conditions at Ueno Zoo. The occurrence of swimming behaviour did not vary between fair and cloudy conditions. However, the birds synchronized the timing of swimming with each other under cloudy conditions, and swimming group size increased under cloudy conditions. […]

Group size: Determinants in the wild and implications for the captive housing of wild mammals in zoos☆

Group size is one of the most important factors influencing the formation and maintenance of successful social groups in captivity. For zoos, appropriate social groupings are of the utmost importance to provide examples of species-typical behaviors, as well as attain captive breeding goals. In the wild, group-living evolved largely in response to the need for […]

Social influences on vigilance behaviour in giraffes, Giraffa camelopardalis

Vigilance in ungulates is considered to have a predominantly antipredator function, with the frequency and duration of scans per individual decreasing with increasing group size. Social influences on vigilance scans have been overlooked in studies on ungulates, although studies in primates and birds show that conspecific scans are important determinants of vigilance behaviour. We investigated […]

Necks and networks: a preliminary study of population structure in the reticulated giraffe (Giraffa camelopardalis reticulata de Winston)

This paper describes a method of scoring the neck pattern of reticulated giraffes as a simple code that can be searched for in an Excel spreadsheet. This enables several hundred individual giraffe to be recognized and repeatedly found within a database. Possible sources of error are described and quantified. Data on group size, dispersal within […]

Effect of Group Size on Activity Budgets of Colobus vellerosus in Ghana

Group size influences foraging efficiency in several primates. We examined the activity budgets of 3 groups of ursine colobus (Colobus vellerosus) at the Boabeng-Fiema Monkey Sanctuary (BFMS) in Ghana to determine whether larger group size induces scramble competition. We studied 2 groups (Bl; N = 7 – 8 and WW; N = 31 – 33) […]

Housing and welfare in laboratory rats: effects of cage stocking density and behavioural predictors of welfare

Using male and female Alderley Park (Wistar-derived) rats housed in single-sex groups in standard laboratory cages, we looked at the effect of group size (one, three, five or eight) on competitive behaviour and time budgeting (initial and longer term), changes in their serum testosterone (males), corticosterone and antibody concentrations, and organ pathology at age 16 […]

A pigheaded compromise: do competition and predation explain variation in warthog group size?

The reproductive payoff to an individual for participating in a group will often be affected by the size of the group. Competition for resources and predation pressure are 2 primary factors that influence sociality and group size in a variety of species. In this correlative study, I investigated how resource competition and predation influenced group […]

Management and husbandry of duikers at the Los Angeles Zoo

Abstract 10.1002/zoo.10020.abs The Los Angeles Zoo has maintained and managed six different species of forest duikers since 1975. Over the years we have achieved relative success with the majority of these species. The maintenance and breeding of duikers has proved to be difficult at best. The major problems that we have experienced concern diet, stress-related […]

Use of space in the domestic fowl: separating the effects of enclosure size, group size and density

An understanding of how confined animals move within the space available to them is essential in the design of effective captive environments that maximize animal welfare. In addition to the obvious effect of enclosure size, other factors such as the number of individuals in the group and their density per unit of area are likely […]