Behavioral Endocrinology and Reproductive Strategies in Wild Female Geladas (Theropithecus gelada).
Year: 2012
Type: article
Abstract: Sexually selected infanticide by males often arises when a new dominant male enters a group that contains unrelated dependent offspring. Under such circumstances, infant deaths hasten their mothers’ return to fertility and translate to male reproductive benefits. In contrast, infanticide poses a salient threat to female reproductive fitness. In response to this threat, females often develop counterstrategies to infanticide such as producing deceptive signs of fertility, prematurely weaning dependent young, forming defensive alliances, or spontaneously aborting a pregnancy. Recent evidence from wild geladas (Theropithecus gelada), a close relative of baboons, suggests that infanticide following male takeovers is a substantial threat for females with dependent offspring. The research described here explores the physiology and function of female response to the threat of infanticide in a wild population of geladas in the Simien Mountain National Park of Ethiopia. This study has three major components. First, we used fecal estrogen metabolites, demographic data, and sexual swellings to establish estimates for life history stages as well as hormonal, behavioral, and sexual swelling profiles across the reproductive stages. These were then used as baseline for investigating the function and potential mechanisms of counterstrategies. Second, we found that demographic factors can mediate infanticide risk for females and found that, following takeovers, female physiological stress response reflects this differential risk. Lastly, we investigated female counterstrategies to infanticide in pregnant and lactating female geladas. We first found unambiguous physiological evidence of spontaneous miscarriages in geladas and illustrated a fitness advantage to females that employed this strategy. In addition, we found demographic and physiological evidence of deceptive fertility following takeovers in lactating female geladas. Together, these results comprise the most complete study of the function and underlying mechanisms (i.e., hormones and behavior) of female reproductive strategies in primates.
Author: Eila K. Roberts
Language: English
Topic: Primate Behavior and Ecology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W205473166