1993/08/01 by AML Colagross, Andrew Cockburn · 1 citation
Environmental Science · Psychology · Biochemistry, Genetics and Molecular Biology · #Wildlife Ecology and Conservation #Primate Behavior and Ecology #Animal Vocal Communication and Behavior
paper · doi:10.1071/zo9930325
openalex publication_date 1993/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Group formation may help animals reduce their risk of predation and allow more time for activities other than vigilance against predators. Eastern grey kangaroos, Macropus giganteus, are gregarious and form open-membership groups. Vigilance behaviour of free-ranging kangaroos was observed in relation-to number of individuals within the group, sex and reproductive status of individuals, proximity to cover and position within the group. Our data support the view that kangaroos adjust their behaviour in relation to the risk of predation. Reproductive females, individuals on the periphery of the group and individuals in groups far from cover were most vigilant. Contrary to previous reports, vigilance behaviour was not influenced by group size except through the edge effect-the tendency of the proportion of individuals on the periphery of the group to decline as group size increases.