Behavioral Ecology and Sociobiology

, Volume 62, Issue 7, pp 1061–1067

Pup production, sex ratios, and survivorship in African wild dogs, Lycaon pictus

Original Paper

DOI: 10.1007/s00265-007-0533-9

Cite this article as:
McNutt, J.W. & Silk, J.B. Behav Ecol Sociobiol (2008) 62: 1061. doi:10.1007/s00265-007-0533-9


The local resource enhancement (LRE) model predicts that in cooperatively breeding species, sex ratios will be biased in favor of the more helpful sex. In this study, we assess the assumptions underlying the LRE model in a population of cooperatively breeding wild dogs (Lycaon pictus) in Northern Botswana monitored over a 15-year period. In this population, litter size and pup survival to 1 year are strongly affected by pack size and the breeding female’s age, but adult males have a stronger and more linear effect on females’ reproductive performance than do adult females. This asymmetry in the benefits derived from male and female helpers is reflected in male-biased sex ratios in litters at the time pups emerge from the den. Sex ratio biases are most pronounced in the litters of the youngest mothers who live in significantly smaller packs than older females. The presence of potential rivals for the dominant female’s position depresses pup production at the time of emergence, suggesting that competition among females for breeding positions may also contribute to the selective forces affecting birth sex ratios.


Cooperative breeding Sex ratio Local resource enhancement Local resource competition Wild dogs Lycaon pictus 

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Botswana Predator Conservation ProjectMaunBotswana
  2. 2.Department of AnthropologyUniversity of CaliforniaLos AngelesUSA

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