Reactions of adult and immature squirrel monkeys to intergroup exposure

Abstract 10.1002/(SICI)1098-2361(1998)17:63.3.CO;2-F Initial encounters between unfamiliar animals raise the practical problem of controlling aggression and provide the opportunity to examine changes in social structure that may occur as groups merge. Social interactions and spatial grouping patterns were examined in newly formed squirrel monkey groups, in which a subgroup of familiar adults was introduced to a […]

Factors affecting aggression in a captive flock of Chilean flamingos (Phoenicopterus chilensis)

Abstract The influence of pair bond status, age and sex on aggression rates in a flock of 84 captive Chilean flamingos at Zoo Atlanta was examined. Analysis showed no difference between aggression rates of male and female flamingos, but adult flamingos had higher rates of aggression than juveniles. There were also significant differences in aggression […]

Relative numerousness judgment and summation in young, middle-aged, and older adult orangutans (Pongo pygmaeus abelii and Pongo pygmaeus pygmaeus)

The ability to select the larger of two quantities ranging from 1 to 5 (relative numerousness judgment [RNJ[) and the ability to select the larger of two pairs of quantities with each pair ranging from 1 to 8 (summation) were evaluated in young, middle-aged, and older adult orangutans (7 Pongo pygmaeus abelii and 2 Pongo […]

Size matters: Impact of item size and quantity on array choice by chimpanzees (Pan troglodytes)

The authors previously reported that chimpanzees ( Pan troglodytes ) showed a striking bias to select the larger of 2 candy arrays, despite a reversed reward contingency in which the animals received the smaller, nonselected array as a reward, except when Arabic numerals were used as stimuli. A perceptual or incentive-based interference occurred that was […]

Comparative behavior of primates. II. Delayed reaction tests on primates at Bronx

Tests were carried out on 18 primates, using the direct method involved in the authors’ previous studies. The results showed “increased capacity in order from the lemur, platyrrhine monkeys, catarrhine monkeys to the baboons. Attention is especially called to the clear superiority of the latter, since they have often been thought inferior. There was found […]

Personality structure, sex differences, and temporal change and stability in wild white-faced capuchins (Cebus capucinus)

Research on nonhuman primate personality dimensions has focused on a small number of taxa, and little of this work has focused on wild populations. We used ratings to assess personality structure in wild white-faced capuchins (Cebus capucinus) over a 9-year period, using a capuchin-specific rating instrument based partly on existing instruments. Adequate levels of interrater […]

Alopecia in three macaque species housed in a laboratory environment

Alopecia is a persistent problem in captive macaque populations and despite recent interest, no factors have been identified that can unequivocally explain the presence of alopecia in a majority of cases. Seasonal, demographic, and environmental factors have been identified as affecting alopecia presentation in rhesus macaques, the most widely studied macaque species. However, few studies […]