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Why male orangutans do not kill infants.
Behavioral Ecology and Sociobiology
|August 25, 2009
Summary
Infanticide is rare in wild orangutans. Limited evidence suggests female counterstrategies and protector male hypotheses are unlikely, with paternity certainty and ranging behavior potentially explaining this pattern.
Area of Science:
- Primate Behavior
- Evolutionary Biology
- Conservation Science
Background:
- Infanticide is a common male strategy in primates.
- Orangutan infanticide has been hypothesized to influence their behavior and social evolution.
- No infanticides have been reported in wild orangutans to date.
Purpose of the Study:
- To critically assess the hypothesis of infanticide as a selection pressure in orangutans.
- To investigate the likelihood of detecting infanticide in studied wild orangutan populations.
- To evaluate female counterstrategies and the protector male hypothesis in orangutans.
Main Methods:
- Review of existing literature on orangutan behavior and socioecology.
- Analysis of potential female counterstrategies against infanticide.
- Assessment of the socioecological benefits of infanticide for male orangutans.
Main Results:
- Limited evidence for female counterstrategies against infanticide in orangutans.
- Little support found for the protector male hypothesis in orangutan social systems.
- Paternity certainty, lactational amenorrhea, and ranging behavior may deter male infanticide.
Conclusions:
- Infanticide is not a regularly employed strategy by male orangutans in Sumatra or Borneo.
- The absence of infanticide may be explained by specific orangutan life-history traits and social dynamics.
- Further research may clarify the evolutionary pressures shaping orangutan social behavior.
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