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The energy storage plays a prominent part in the life histories of many animals inhabiting cold harsh environment, thus anuran amphibians rely on larger residual energy stores from post-hibernation to cope with unfavourable weather conditions before breeding. As the habitat conditions often change in different locations, selective pressure for energy storage could also vary. However, we still have limited knowledge on whether anurans living under different environmental backgrounds would adopt suitable strategies to cope with energy demands during reproduction. Here, we examined patterns of energy storage in spring (after hibernation and before reproduction) in seven plateau brown frog (Rana kukunoris) populations with different climatic conditions in the eastern Tibetan Plateau. After removing the effects of age and body size, liver weights of both sexes and fat body weights in males were negatively correlated with temperature, suggesting that these reserves were critical for this anuran to survive through harsh and extended dormancy period under uncertain environmental conditions. Additionally, reproductive investment in both sexes could partly explain the increase in post-hibernation energy stores with decreasing temperature. Males had relatively heavier liver and fat body weights than females, indicating that males store more energy reserves for breeding activity compared with females. Therefore, we suggest that both the variation of environmental conditions and sexual differentiation of reproductive roles play a prominent role in shaping the energy allocation and reserve patterns in the dormancy and breeding of amphibian species. [ABSTRACT FROM AUTHOR]

On the southeastern Tibetan Plateau, an area widely covered by alpine glaciers, two types of debris flow generally occur: glacier-related debris flows (GDFs) and rainfall-related debris flows (RDFs). It is widely accepted that topographic conditions influence debris flow activities; however, few studies have examined the differences between such influence on GDFs and RDFs. This study investigated the GDFs and RDFs in the periglacial area of the Parlung Tsangpo Basin, and calculated 12 geomorphic indexes to reveal the topographic features associated with these two types of debris flow. It was found that lower values in the drainage area, main channel length, and relative elevation occurred in RDFs compared to the GDFs. In contrast, higher values in the channel gradient, relief ratio, and effective basin area appeared in RDFs. The discrepancy is mainly related to the different topographic and geomorphic shaping of modern glaciers. According to its geomorphological characteristics, the Parlung Tsangpo Basin can be divided into the upper V-shaped canyon section, middle wide valley section, and lower steep canyon section. The scale and frequency of debris flow in the upstream canyon region are substantially lower than those in the downstream. Moreover, the frequency and scale of RDFs are considerably different from those of GDFs, primarily because of the different geomorphic evolutionary stages of debris flow gullies in different regions. [ABSTRACT FROM AUTHOR]

Environmental stress is generally regarded as an important evolutionary force for promoting the differentiation of shape, structure and function of animal organs closely related to survival and reproduction. Geographical variation of temperature and corresponding change in intensity of male-male competition might drive inter-population differences in directional testes asymmetry (DTA). Here, we investigated inter-population variation in DTA of the brown frog (Rana kukunoris) at seven different altitudes on the eastern Tibetan Plateau. We found that the size of right testes increased with temperature, but not left testes. We also found that male age, body mass or body condition, and testis mass had not effect on DTA, suggesting that heavier or older R. kukunoris males or those with larger testes had not stronger DTA. The operational sex ratio did not affect DTA, but there was a positive correlation between DTA and temperature, suggesting that differences in the length of activity period and resources availability across locations may affect the energy budget of this frog, resulting in a gradual change in reproduction energy parallel to increasing temperature. [ABSTRACT FROM AUTHOR]

The article discusses a study on the age and body size of two populations of the frog Rana kukunoris, which is endemic to the eastern Tibetan plateau. The study compared these two qualities in breeding frogs from two localities at different altitudes with the aim of providing basic demographic information and understanding the relationship of age and body size with local climate conditions. Skeletochronology was used to determine the age of the frog specimens. It was found that the minimum age at maturity for male frogs was three years and four years for females. A positive correlation between age and body size for males and females at both study sites was observed.