D A Collins

Publications (4)78.96 Total impact

• Article: Human impacts, disease risk, and population dynamics in the chimpanzees of Gombe National Park, Tanzania

  A. E. Pusey, M. L. Wilson, D. A. Collins
  American Journal of Primatology. 01/2008; 70(8):738-744.
• Source

  Available from: nih.gov

  Article: Problems with primate sex ratios.

  C Packer, D A Collins, L E Eberly
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  ABSTRACT: Birth sex ratios of baboons in Gombe National Park, Tanzania, show an overall male bias of ca. 20%, but there is no obvious explanation for this trend. Individual females did not alter their sex ratios according to persistent levels of local resource competition. Sex ratios showed an unexpected relationship between age and rank: subordinate females had more sons when they were young; dominant females had more sons when they were old. The sex ratio of low-ranking females also varied with the severity of environmental conditions during pregnancy. Our findings suggest that mammalian sex ratios might be the product of more complex processes than is generally recognized or that sex-determining mechanisms impose sufficient constraints to prevent adaptive variation in all contexts.
  Philosophical Transactions of The Royal Society B Biological Sciences 12/2000; 355(1403):1627-35. · 6.40 Impact Factor
• Article: Nuclear DNA from primate dung.

  J J Constable, C Packer, D A Collins, A E Pusey
  Nature 03/1995; 373(6513):393. · 36.28 Impact Factor
• Article: Reproductive constraints on aggressive competition in female baboons.

  C Packer, D A Collins, A Sindimwo, J Goodall
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  ABSTRACT: Competitive interaction between females of same social group is characteristic of most primate species. In Old World monkeys, females of high social rank maintain priority of access to scarce resources and harass low-ranking companions. But different field studies have found differing correlations between female dominance and reproductive success: several populations show an advantage of rank whereas others do not. Although such variation may reflect divergent levels of predation, food availability or social stress in different environments, female competitive ability may also be balanced by significant reproductive costs and thus be subject to strong stabilizing selection. We report here that high-ranking female baboons (Papio cynocephalus anubis) at Gombe National Park, Tanzania, enjoy shorter interbirth intervals, improved infant survival, and accelerated maturation of their daughters. These advantages, however, are countered by a significantly higher probability of miscarriage, and a proportion of high-ranking females suffer from reduced fertility.
  Nature 02/1995; 373(6509):60-3. · 36.28 Impact Factor