Determination of the causes of infanticide in capybara (Hydrochaeris hydrochaeris) groups in captivity

The capybara (Hydrochaeris hydrochaeris) is a wild rodent of great economic al interest, which are easily domesticated. Breeding these animals in capti vity constitutes a great problem due to the high rate of offspring mortalit y caused by infanticide. To determine the causes of the infanticides, 64 ca pybara births were analyzed in order to study the relation of offspring dea ths with the lack experience of primiparous females, place of parturition-m aternity pen (isolated) vs. reproduction pen (in-group) or familiarity amon g group members. The hypothesis that primiparous females kill their own off spring was discarded. The data revealed that the infanticides were associat ed with reproductive groups containing females who have not been together s ince weaning (unfamiliar females) in spite of living together without appar ent conflicts until the occurrence of births, when they killed the companio ns' offspring. This study revealed that when groups are set up of females t hat were living together since weaning, there is no need to isolate the fem ales for parturition. (C) 1999 Elsevier Science B.V. All rights reserved.