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Female chimpanzees use copulation calls flexibly to prevent social competition.

Townsend SW, Deschner T, Zuberbühler K - PLoS ONE (2008)

Bottom Line: Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring.We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis.Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of St Andrews, St Andrews, Scotland, United Kingdom.

ABSTRACT
The adaptive function of copulation calls in female primates has been debated for years. One influential idea is that copulation calls are a sexually selected trait, which enables females to advertise their receptive state to males. Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring. We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis. Hormone analysis showed that the calling behaviour of copulating females was unrelated to their fertile period and likelihood of conception. Instead, females called significantly more while with high-ranking males, but suppressed their calls if high-ranking females were nearby. Copulation calling may therefore be one potential strategy employed by female chimpanzees to advertise receptivity to high-ranked males, confuse paternity and secure future support from these socially important individuals. Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition.

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Related in: MedlinePlus

Individual variation in copulation calling behaviour.Line graphs showing the proportion of copulations accompanied by a call when copulating with high (N = 5) and low (N = 3) ranking males for each of the seven females.
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pone-0002431-g002: Individual variation in copulation calling behaviour.Line graphs showing the proportion of copulations accompanied by a call when copulating with high (N = 5) and low (N = 3) ranking males for each of the seven females.

Mentions: All seven monitored females gave copulation calls during mating, but only in a minority of cases: The females copulated a total of 287 times and produced copulation calls during only 104 (36%) of copulations (table 1). The females were more likely to produce copulation calls when they mated with high-ranking adult males than low-ranking males (Wilcoxon exact test N females = 7, Z = −2.37, p = 0.016, fig 1), with all seven females showing the same pattern (Cronbach's alpha test for reliability = 0.791, fig 2). There was no difference in calling behaviour when females copulated with low-ranked adult males and even lower-ranking subadult males (Wilcoxon exact test N females = 7, Z = −0.405, p = 0.813)


Female chimpanzees use copulation calls flexibly to prevent social competition.

Townsend SW, Deschner T, Zuberbühler K - PLoS ONE (2008)

Individual variation in copulation calling behaviour.Line graphs showing the proportion of copulations accompanied by a call when copulating with high (N = 5) and low (N = 3) ranking males for each of the seven females.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3278306&req=5

pone-0002431-g002: Individual variation in copulation calling behaviour.Line graphs showing the proportion of copulations accompanied by a call when copulating with high (N = 5) and low (N = 3) ranking males for each of the seven females.
Mentions: All seven monitored females gave copulation calls during mating, but only in a minority of cases: The females copulated a total of 287 times and produced copulation calls during only 104 (36%) of copulations (table 1). The females were more likely to produce copulation calls when they mated with high-ranking adult males than low-ranking males (Wilcoxon exact test N females = 7, Z = −2.37, p = 0.016, fig 1), with all seven females showing the same pattern (Cronbach's alpha test for reliability = 0.791, fig 2). There was no difference in calling behaviour when females copulated with low-ranked adult males and even lower-ranking subadult males (Wilcoxon exact test N females = 7, Z = −0.405, p = 0.813)

Bottom Line: Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring.We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis.Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of St Andrews, St Andrews, Scotland, United Kingdom.

ABSTRACT
The adaptive function of copulation calls in female primates has been debated for years. One influential idea is that copulation calls are a sexually selected trait, which enables females to advertise their receptive state to males. Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring. We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis. Hormone analysis showed that the calling behaviour of copulating females was unrelated to their fertile period and likelihood of conception. Instead, females called significantly more while with high-ranking males, but suppressed their calls if high-ranking females were nearby. Copulation calling may therefore be one potential strategy employed by female chimpanzees to advertise receptivity to high-ranked males, confuse paternity and secure future support from these socially important individuals. Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition.

Show MeSH
Related in: MedlinePlus