Declining body size in an endangered large mammal

作者：McNutt J Weldon; Gusset Markus^*

来源：Biological Journal of the Linnean Society, 2012, 105(1): 8-12.

DOI：10.1111/j.1095-8312.2011.01785.x

• eco-evolutionary dynamics
• energy expenditure
• Lycaon pictus
• phenotypic change
• resource rule

Body size affects almost every aspect of the biology of a species. According to the resource rule, decreasing resource availability (e.g. prey density) will lead to a reduction in body size or, alternatively, a decline in mass-independent energy expenditure. In the present study, we provide a test of this hypothesis, assessing the effect of significantly decreasing prey density on endangered African wild dog (Lycaon pictus) body size and energy expenditure over a 20-year period. As predicted from the resource rule, decreasing resource availability resulted in energetic re-allocation: wild dogs' body size decreased significantly (both shorter and slimmer), whereas our fitness-related measure of energy expenditure (i.e. litter size) remained constant over time. A phenotypic change of up to 17% within 20 years, as found in the present study, appears to be unprecedented in a nonharvested large mammal, thus advancing the emerging field of eco-evolutionary dynamics.

• 出版日期2012-1