Research conducted by the School of Anthropology and Conservation has suggested that the sexual selection hypothesis for infanticide may be the key driver for the high rate of infant killings among a community of chimpanzees in Uganda.<\/p>\n
Led by PhD student\u00a0Adriana Lowe<\/strong>\u00a0and\u00a0Dr Nicholas Newton-Fisher<\/a><\/strong>\u00a0from the University\u2019s\u00a0Living Primates Research Group<\/a><\/strong>, the research team analysed the records of infanticides and failed attempts at infanticide over a\u00a024-year period\u00a0in the Sonso community of chimpanzees in the\u00a0Budongo Forest<\/a>.<\/p>\n While relatively rare, infanticide is well documented in chimpanzees but those in the Sonso community are\u00a0more prone to practice it than others\u00a0that have been studied, with infanticide the\u00a0most common cause of infant death\u00a0there. However, although various explanations have been proposed, this study is the first to thoroughly investigate the phenomenon.<\/p>\n For the study,\u00a0the team analysed 33 attacks on 30 victims from a single community of chimpanzees between 1993 and 2017. From this they were able to determine that 11 of the attacks were \u2018definite\u2019 infanticides, four \u2018almost certain\u2019, nine \u2018suspected\u2019, and nine \u2018attempted\u2019.\u00a0Most attacks were by adult males, and the victims were often very young: two thirds were under one week old. The team also noted incidents of\u00a0partial cannibalism.<\/p>\n From their analysis and observations they concluded that the\u00a0sexual selection hypothesis\u00a0\u2013 the idea that\u00a0male chimpanzees will kill infants other than their own\u00a0so they have a better chance of fathering the mother\u2019s next infant \u2013 was the\u00a0main reason for the high rates of infanticide. For example, females who lost an infant to infanticide\u00a0conceived on average around seven times more quickly\u00a0than if their infant had survived, with the majority of mothers who lost infants going on to reproduce again within the community.<\/p>\n The team found\u00a0no evidence to suggest that infanticide was part of a male strategy to eliminate future competitors.<\/p>\n Dr Newton-Fisher<\/a>, who has studied infanticide in the Sonso community since the 1990s, said, “Sexually-selected infanticide\u00a0involves the reduction in time until the mother is free to mate again that a male could bring about by killing her present infant. However, we did identify\u00a0examples of infanticide by females. Although\u00a0rare, in those cases we suggest that they may use infanticide to drive away rival mothers, who would otherwise\u00a0compete with them for food.<\/p>\n “We also discovered rare occurrences of partial cannibalism within the community, suggesting\u00a0meat acquisition was a by-product of the infanticide.”<\/p>\n The report, Intra-community infanticide in wild, eastern chimpanzees: a 24-year review<\/a>\u00a0(Adriana Lowe and Nicholas Newton-Fisher, University of Kent; Catherine Hobaiter<\/a>,\u00a0St Andrews University; Caroline Asiimwe<\/a>,\u00a0Budongo Conservation Field Station, Uganda; and Klaus Zuberb\u00fchler,\u00a0Institute of Biology, Neuchatel, Switzerland) is published in the journal\u00a0Primates<\/em><\/a>.<\/p>\n The Living Primates Group\u00a0is part of the\u00a0School of Anthropology and Conservation. Its\u00a0research\u00a0<\/a>focuses on\u00a0wild primates, in particular chimpanzees (Pan troglodytes) in both West and East Africa, and capuchin monkeys (Sapajus\/Cebus apella) in Argentina.<\/p>\n","protected":false},"excerpt":{"rendered":"