Abstract

GOROSABEL, Antonella; LOPONTE, Daniel  and  CORRIALE, María J. Mortalidad estacional de carpinchos (Hydrochoerus hydrochaeris) y su relación con la disponibilidad de recursos en los Esteros del Iberá, Argentina . Mastozool. neotrop. [online]. 2016, vol.23, n.2, pp.401-413. ISSN 0327-9383.

The capybara (Hydrochoerus hydrochaeris) is a semi-aquatic rodent that inhabits the tropical, subtropical and temperate lowland wetlands of South America. We analyzed mortality of a population of capybaras and its relation to resource availability in two contrasting climatic-hydrological seasons in an area free from hunting pressure in the Iberá wetlands of Argentina. The number, age and sex of dead individuals was determined in late summer and in winter based on dead individuals and bone material collection on fourteen 3-km transects. The age category of dead individuals was estimated based on the degree of ossification of cranial sutures, and sex of adults by the width of the incisors. The age struc­ture and the sex ratio of social groups in the population was estimated by direct observation in 18 randomly selected social groups, and seasonal variation in the availability of food and shelter were estimated. Mortality was greater during winter than summer (140 vs. 49 mortalities, respectively), especially of adults and, among this group, of males. Estimates of the availability of forage and shelter were lower in winter than summer. Both resource availability and the physical condition of the environment during winter appear to affect mortality and population structure of the capybara.

Keywords : Age structure; Resource availability; Sex ratio; Wetlands.