Resource utilization and territoriality in group-living capybaras (Hydrochoerus hydrochaeris)

Groups of capybaras living in the seasonally flooded savannas of Venezuela showed seasonal shifts in habitat use in relation to changes in availability of favourable habitat (mainly grassland) caused by the alternation of drought and flooding. Group home-ranges were stable; certain activities (eg resting, grazing, wallowing) were largely restricted to specific localities within each range. Although groups fed on the most favourable habitat in relation to its availability, individuals fed for similar amounts of time in this habitat irrespective of its availability per head. Groups of capybaras were territorial. Territory size varied between 5-16 ha (10.4±3.7 ha) and was positively correlated with group size. All home-ranges (1 exception) had a section of each of 4 major habitat types. The areas of 2 of these habitat types (bush scrub and low-lying grassy patches) correlated significantly with group size. The area of bushy scrub in each home-range correlated with the reproductive success of females occupying it. These 2 habitats are essential for survival in the dry season (grassy patches) and wet season (bushy scrub). Capybaras depend upon access to permanent surface water. Where there is such water, territories are configured to encompass sufficient resources to ensure survival under widely different seasonal conditions. -from Authors