Lethal intergroup aggression leads to territorial expansion in wild chimpanzees

  title={Lethal intergroup aggression leads to territorial expansion in wild chimpanzees},
  author={John C. Mitani and David P. Watts and Sylvia J. Amsler},
  journal={Current Biology},
Summary Chimpanzees make lethal coalitionary attacks on members of other groups [1]. This behavior generates considerable attention because it resembles lethal intergroup raiding in humans [2]. Similarities are nevertheless difficult to evaluate because the function of lethal intergroup aggression by chimpanzees remains unclear. One prominent hypothesis suggests that chimpanzees attack neighbors to expand their territories and to gain access to more food [2]. Two cases apparently support this… Expand
Lethal Coalitionary Aggression Associated with a Community Fission in Chimpanzees (Pan troglodytes) at Ngogo, Kibale National Park, Uganda
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The hypothesis that intergroup aggression evolved according to the same functional principles in the two species—selection favoring a tendency to kill members of neighboring groups when killing could be carried out safely is evaluated. Expand
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The first account of the killing of an incumbent alpha male by a coalition of adult males from the same community is provided; the lethal attack triggered a period of instability in the male hierarchy and was likely an opportunistic attempt to seize alpha status by the third‐ranking male. Expand
Why do chimpanzee males attack the females of neighboring communities?
A simple mathematical model is developed based on reproductive skew among primate males that predicts that it is advantageous for high-ranking males but not for low- ranking males to attack females, and that fatal attacks on females should be concentrated in communities with low reproductive skew. Expand
Lethal coalitionary attacks of chimpanzees (Pan troglodytes troglodytes) on gorillas (Gorilla gorilla gorilla) in the wild
The first information of two lethal coalitionary attacks of chimpanzees on another hominid species, western lowland gorillas (Gorilla gorilla gorilla), that occur sympatrically in the Loango National Park in Gabon are provided. Expand
Lethal aggression in Pan is better explained by adaptive strategies than human impacts
It is found that males were the most frequent attackers and victims; most killings involved intercommunity attacks; and attackers greatly outnumbered their victims (median 8:1 ratio). Expand
Intercommunity interactions and killings in central chimpanzees (Pan troglodytes troglodytes) from Loango National Park, Gabon
First insights into intercommunity interactions of individuals of a community of central chimpanzees living in the Loango National Park in Gabon suggest that the frequency of lethal attacks at Loango is comparable to that reported for the eastern subspecies and female involvement in inter community interactions mirrors that of the western subspecies. Expand
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Male chimpanzees, Pan troglodytes, defend group territories, and sometimes injure or kill members of other groups. To test which factors best predict the occurrence and outcomes of intergroupExpand
Genetic analyses suggest no immigration of adult females and their offspring into the Sonso community of chimpanzees in the Budongo Forest Reserve, Uganda
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Genetic differentiation and the evolution of cooperation in chimpanzees and humans
Levels of between-group genetic differentiation in contemporary humans are lower than those used in previous tests, and not higher than those of chimpanzees, which suggests that the identification of other factors that differ between chimpanzees and humans may be needed to provide a compelling explanation of why humans, but not chimpanzees, display the unique features of human cooperation. Expand


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How the demographic context affects the possible range of behavioral options open to individuals and ultimately contributes to the explanation of behavioral diversity in chimpanzees is illustrated. Expand
▪ Abstract In the 1970s, researchers provided the first detailed descriptions of intergroup conflict in chimpanzees. These observations stimulated numerous comparisons between chimpanzee violence andExpand
Evolution of coalitionary killing.
  • R. Wrangham
  • Sociology, Medicine
  • American journal of physical anthropology
  • 1999
Current evidence supports the hypothesis that selection has favored a hunt-and-kill propensity in chimpanzees and humans, and that coalitional killing has a long history in the evolution of both species. Expand
Comparative rates of violence in chimpanzees and humans
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It is suggested that males defend a feeding territory for their resident females and protect them from sexual harassment in Gombe chimpanzees, and a large range may eventually attract more females, but this is not an immediate consequence of range expansion. Expand
Group extinction and female transfer in wild chimpanzees in the Mahale National Park, Tanzania.
and Summary A unit-group (K-group) of chimpanzees has shown a drastic demographic change in the course of 17 years (1966–1983) of field study. K-group had 6 adult males in 1966. Initially, theExpand
Did Warfare Among Ancestral Hunter-Gatherers Affect the Evolution of Human Social Behaviors?
A model of the evolutionary impact of between-group competition and a new data set that combines archaeological evidence on causes of death during the Late Pleistocene and early Holocene with ethnographic and historical reports on hunter-gatherer populations finds that the estimated level of mortality in intergroup conflicts would have had substantial effects, allowing the proliferation of group-beneficial behaviors that were quite costly to the individual altruist. Expand
The Myth of Man the Hunter, Man the Killer and the Evolution of Human Morality
Since the discovery of the first man-ape, many have assumed that the earliest humans were hunters and that this was associated with a “killer instinct.” The myth of “man the hunter” was repeated inExpand
War in Human Civilization
  • A. Gat
  • History, Political Science
  • 2006
PART 1: WARFARE IN THE FIRST TWO MILLION YEARS: ENVIRONMENT, GENES, AND CULTURE 1. Introduction: The Human 'State of Nature' 2. Peaceful or War-like: Did Hunter-Gatherers Fight? 3. Why Fighting? TheExpand
The structure of a complete phytochrome sensory module in the Pr ground state
The ground state structure of the complete sensory module of Cph1 phytochrome from the cyanobacterium Synechocystis 6803 is reported, and it is shown that the PHY domain, previously considered unique to phY, is structurally a member of the GAF (cGMP phosphodiesterase/adenylyl cyclase/FhlA) family. Expand