Higher Pre-Hibernation Energy Storage in Anurans from Cold Environments: A Case Study on a Temperate FrogRana chensinensisAlong a Broad Latitudinal and Altitudinal Gradients

Abstract

Temperate amphibians in colder regions are expected to store more energy prior to hibernation for successful overwintering and subsequent spring breeding. We tested this prediction on a capital breeding species — Rana chensinensis — using samples collected from 27 populations across 1200-km latitudinal (33.6–4.2°N) and 1768-m (112–1880 m) altitudinal gradient in northern China. Our data showed that frogs from colder regions (high latitude or altitude) had relatively heavier liver and fat bodies than those from warmer regions, but that the weight of carcasses tended to become smaller. The greater pre-hibernation energy reserves in colder regions could be an adaptive response to the longer and colder winter period, whereby meeting the energy demands for overwintering, and the subsequent energy requirements of reproduction in the spring.