TY - JOUR
T1 - The context of female dispersal in Kanyawara chimpanzees
AU - Stumpf, R. M.
AU - Emery Thompson, M.
AU - Muller, M. N.
AU - Wrangham, R. W.
N1 - We thank the Uganda Wildlife Authority, Uganda National Council for Science and Technology, Makerere University Biological Field Station, and J. Kasenene for research permissions and local support. Daily chimpanzee observations were conducted by field assistants F. Mugurusi, P. Tuhairwe, the late D. Muhangyi, the late J. Barwogeza, the late C. Muruuli, C. Katongole, Sunday John, J. Kyomuhando, S. Musana, J. Musunguzi, D. Sebugwawo and C. Itumba. We thank field managers C. Hooven, M. Wilson, K. Pieta, K. Duffy, A. Houle and E. Otali. Additional thanks to J.D. Polk and C. Rasmussen for assistance in preparation of the manuscript, J. Moore, K. Jack, and one anonymous reviewer for valuable comments and suggestions, and K. Jack and L. Isbell for inviting us to contribute to this special issue. Kanyawara research was funded by the U.S. National Science Foundation (grant no. 0416125), the L.S.B. Leakey Foundation, and the Wenner-Gren Foundation.
PY - 2009/4/1
Y1 - 2009/4/1
N2 - In most social mammals, members of either one sex or both leave their natal group at sexual maturity. In catarrhine primates, male emigration is the predominant pattern. Female philopatry facilitates cooperation among kin, and female reproductive success is influenced by these relationships. Chimpanzees (Pan troglodytes) are unusual in that dispersal is almost exclusively by females. While plausible ultimate hypotheses can explain this dispersal pattern, the proximate causes of female dispersal are unknown and warrant examination due to variation in dispersal behaviour and the associated high costs of immigration. In this study, we examine the behavioural and hormonal context of female dispersal in chimpanzees of Kibale National Park, Uganda, in order to understand variation in dispersal patterns and gain insight into functional explanations. Using over 10 years of behavioural, endocrinological, and demographic records, we examined the significance of 5 potential predictors of the timing of dispersal: (1) maturational state; (2) association patterns; (3) mating patterns; (4) physiological stress; and (5) feeding ecology. Female dispersal was not strictly predicted by chronological or gynaecological age, and dispersal did not correlate with shifts in glucocorticoid levels. We found no evidence that females avoided mating in their natal group, even with known relatives, suggesting that inbreeding avoidance is not a sufficient proximate explanation for dispersal in chimpanzees. Instead, variation in social development and the availability of energy for dispersal were implicated and necessitate more intensive examination along with subtler variation in maturational trajectories.
AB - In most social mammals, members of either one sex or both leave their natal group at sexual maturity. In catarrhine primates, male emigration is the predominant pattern. Female philopatry facilitates cooperation among kin, and female reproductive success is influenced by these relationships. Chimpanzees (Pan troglodytes) are unusual in that dispersal is almost exclusively by females. While plausible ultimate hypotheses can explain this dispersal pattern, the proximate causes of female dispersal are unknown and warrant examination due to variation in dispersal behaviour and the associated high costs of immigration. In this study, we examine the behavioural and hormonal context of female dispersal in chimpanzees of Kibale National Park, Uganda, in order to understand variation in dispersal patterns and gain insight into functional explanations. Using over 10 years of behavioural, endocrinological, and demographic records, we examined the significance of 5 potential predictors of the timing of dispersal: (1) maturational state; (2) association patterns; (3) mating patterns; (4) physiological stress; and (5) feeding ecology. Female dispersal was not strictly predicted by chronological or gynaecological age, and dispersal did not correlate with shifts in glucocorticoid levels. We found no evidence that females avoided mating in their natal group, even with known relatives, suggesting that inbreeding avoidance is not a sufficient proximate explanation for dispersal in chimpanzees. Instead, variation in social development and the availability of energy for dispersal were implicated and necessitate more intensive examination along with subtler variation in maturational trajectories.
KW - Adolescence
KW - Dispersal
KW - Energetics
KW - Inbreeding
KW - Stress
UR - http://www.scopus.com/inward/record.url?scp=66749126768&partnerID=8YFLogxK
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U2 - 10.1163/156853909X413853
DO - 10.1163/156853909X413853
M3 - Article
AN - SCOPUS:66749126768
SN - 0005-7959
VL - 146
SP - 629
EP - 656
JO - Behaviour
JF - Behaviour
IS - 4-5
ER -