Evidence of an infanticide in black-horned capuchin monkeys (Sapajus nigritus) in an Atlantic Forest remnant in Argentina

Abstract

An infanticide is a rare event but has important impact in primate populations. The black-horned capuchin monkey, Sapajus nigritus, is a native species from the Atlantic Forest. Previous reports of infanticide in this species are explained with the 'sexual-selection' hypothesis, and occur in large groups and after a dominant male replacement. Here we provide evidence of a new case of infanticide by a non-identified member of a wild group of S. nigritus, in a remnant of the Atlantic Forest under anthropogenic disturbance. Our study group (30-35 individuals) overlapped its home range with other species' groups in an isolated forest fragment (570 ha). This primate overcrowding in a small area may have increased social intolerance and aggression. In this regard, this infanticide event may be associated to a non-adaptive explanation such as the social pathology hypothesis.