Age and body size of Rana kukunoris, a high-elevation frog native to the Tibetan plateau

We compared age and body size of breeding individuals between two populations of Rana kukunoris, a species endemic to the eastern Tibetan plateau, at different altitudes (3400 m and 3100 m). Minimum age at maturity was three years for males and four years for females at 3400 m, and three years in both sexes at 3100 m. The oldest males were seven (3400 m) and six (3400 m) years old, and the maximum age in females was eight years in both populations; there was no significant difference in age structure between the two populations. Frogs at 3400 m had an average body length of 47.7 mm (+/- 0.18) in males and 54.8 mm (+/- 0.27) in females, significantly shorter than the 49.5 mm (+/- 0.60) and 59.7 mm (+/- 0.40) in males and females at 3100 m, respectively. At both sites, females were significantly larger than males. The reduced body size might be attributable to the shorter growing season at the higher site, and the sex difference in body size could be associated with earlier maturity in males than in females.