Foraging patterns of capybaras in a seasonally flooded savanna of Venezuela

The foraging behaviour of capybaras (Hydrochaeris hydrochaeris) was assessed in relation to habitat and season in a flooded savanna of Venezuela from February (dry season) 1993 to June (rainy season) 1994. Direct observations were carried out to record group movements and foraging activities of individual capybaras when feeding on specific plant species. The time devoted to feeding upon some species was recorded in relation to total foraging time (feeding + searching). Capybaras spent similar times feeding on reeds (Eleocharis interstincta; Cyperaceae) and Paratheria prostrata (Poaceae) patches during the dry season though plant quality was different. During the rainy season, reeds were almost ignored by the animals which fed mainly on Hymenachne aplexicaulis, a grass with a significantly higher content of energy and protein. Capybaras fed for longer time during the dry season but more selectively during the rainy season. Capybaras were the dominant grazers in this flooded savanna as inferred from the comparative effects they produced in the height, biomass and quality of the pasture in relation to those effects produced by other vertebrate herbivores, namely, cattle, feral horses and asses.