Infanticide in black capuchin monkeys (Cebus apella nigritus) in Iguazú National Park, Argentina

Abstract

We report here one observed and two potential cases of infanticide during a brief period of 1 month after a dominant male replacement in one group of black capuchin monkeys in Iguazú National Park, Argentina. We also compile infant disappearances and demographic data in seven groups followed from 1-14 years. Behavioral and molecular data showed that the probability that an infanticidal male would kill his own progeny is very low in this species. Females that lost infants less than 6 months old had shorter interbirth intervals than females whose infants survived (14.12 ± 5.32 months, n=17 vs. 20.42 ± 5.65 months, n=34). Females whose infants die shortly after takeovers mate with the presumed infanticidal male during the most fertile days of their subsequent estrous periods giving this male a high probability of siring the new progeny. We recorded 181 proceptive periods and 52 births from 18 adult females in two groups. Most proceptive periods were concentrated during a conception season, but there was an increase in sexual behavior after male takeovers. Seven females copulated while pregnant after the observed male takeover, an unusual behavior in this species in years of group stability. Of 24 infants born during takeover years, 62.5% did not survive the first year, whereas only 22.5% of 80 infants died in years without male replacements. We found a significant positive association between infant mortality and male takeovers, but not with food provisioning. The main cause of infant mortality in this population is associated with male takeovers. Our results suggest that infanticide can have an important effect on the behavior of this species, selecting for female behaviors that function to reduce infanticide risk.

Social relationships between adult females and the alpha male in wild tufted capuchin monkeys

“…Evidence for tolerance at food resources, food sharing, infant protection and infant caring during resting periods by the alpha male toward its potential offspring have also been reported [Escobar-Páramo, 1999;Ferreira et al, 2006]. Therefore, tufted capuchin females may benefit from associating with alpha males by increasing the probability of support during conflicts, by gaining access to food resources, and by decreasing the risk of infanticide, which has been reported in this genus [Fedigan, 2003;Izar et al, 2007;Manson et al, 2004;Ramirez-Llorens et al, 2008;Valderrama et al, 1990].…”

Relato de caso de morte por agressão entre macacos-prego <i>Sapajus nigritus</i> (Primates: Cebidae) no Jardim Botânico do Rio de Janeiro

“…Uma quarta possibilidade seria de um conflito intragrupal no grupo 2. Conflitos intragrupais, incluindo infanticídio, podem resultar em graves ferimentos ou mortes por consequência de uma disputa pela hierarquia do grupo, como fora relatado em Cebus capucinus e Sapajus nigritus (Gros-Louis et al, 2003;Izar et al, 2007;Ramírez-Llorens et al, 2008;Rose, 1994;Lynch & Rímoli, 2000;Scarry e Tujague, 2012). Os conflitos intragrupais são potenciais pressões seletivas para o comportamento e dinâmica dos machos e fêmeas nos grupos.…”

“…Interações agressivas resultando em morte têm sido relatadas em primatas não-humanos como chimpanzés (Wrangham, 1999;Watts & Mitani, 2001), gorilas-da-montanha (Watts, 1989), colobus-vermelhos (Starin, 1994), Muriqui-do-sul (Talebi et al, 2009) e também em caiararas (Miller, 1998;Gros-Louis et al, 2003), e em macacos-pregos (Ramírez-Llorens et al, 2008;Scarry e Tujague, 2012). A manutenção do monopólio sobre os recursos alimentares na área de vida e/ou sobre as potenciais parceiras reprodutivas, são fatores que exercem forte pressão sobre animais sociais, principalmente em primatas, fazendo com que os animais invistam em interações agonísticas intensas.…”

“…Sapajus apella, por exemplo, parece ser menos agressivo durante encontros intergrupais do que Cebus capucinus e C. albifrons (Becker & Berkson, 1979;Defler, 1982;Perry 1996;Gros-Louis et al, 2003;Ramírez-Llorens et al, 2008). As disputas de poder são eventos bastante conflitantes podendo resultar em morte em Cebus (GrosLouis et al, 2003;Scarry e Tujague, 2012).…”

“…As disputas de poder são eventos bastante conflitantes podendo resultar em morte em Cebus (GrosLouis et al, 2003;Scarry e Tujague, 2012). Muitos estudos com ambos os gêneros relatam casos de infanticídio por machos assim que conquistam o mais alto nível hierárquico do grupo (Izar et al, 2007;Ramírez-Llorens et al 2008;Rose, 1994), o que reforça o quadro agonístico dos casos de disputa hierárquica. O presente estudo relata o caso de um indivíduo de macaco-prego (Sapajus nigritus -Goldfuss, 1809) macho adulto, encontrado gravemente ferido no arboreto do Jardim Botânico do Rio de Janeiro, pelos pesquisadores do Projeto de Conservação da Fauna.…”