Reproducing females can allocate energy between the production of eggs or offspring of different size or number, both of which can strongly influence fitness. The physical capacity to store developing offspring imposes constraints on maximum clutch volume, but individual females and populations can trade off whether more or fewer eggs or offspring are produced, and their relative sizes. Harsh environments are likely to select for larger egg or offspring size, and many vertebrate populations compensate for this reproductive investment through an increase in female body size. We report a different trade-off in a frog endemic to the Tibetan Plateau, Rana kukunoris. Females living at higher altitudes (n = 11 populations, 2000-3500 m) produce larger eggs, but without a concomitant increase in female body size or clutch size. The reduced diel and seasonal activity at high altitudes may impose constraints on the maximum body size of adult frogs, by limiting the opportunity for energy accumulation. Simultaneously, producing larger eggs likely helps to increase the rate of embryonic development, causing tadpoles to hatch earlier. The gelatinous matrix surrounding eggs, more of which is produced by large females, may help buffer developing embryos from temperature fluctuations or offer protection from ultraviolet radiation. High-altitude frogs on the Tibetan Plateau employ a reproductive strategy that favours large egg size independent of body size, which is unusual in amphibians. The harsh and unpredictable environmental conditions at high altitudes can thus impose strong and opposing selection pressures on adult and embryonic life stages, both of which can simultaneously influence fitness.
Cervus albirostris (white-lipped deer) is an endemic species in China. As the name implies, C. albirostris has a characteristic pure white marking around their mouth and on the underside of the throat. The animal is a typical alpine species normally living at the height of 3500-4300 m. In this study, by pyrosequencing the 16S rRNA gene sequences, we for the first time analyzed the gut bacterial community composition in eight feces samples of wild C. albirostris. From a total of 243,634 high-quality sequences, we identified 186 genera, included in 17 prokaryotic phyla in the feces. The relative proportions of Firmicutes and Bacteroidetes were highly consistent in each individual sample. The most frequently detected genus was Ruminococcaceae UCG-005, ranging from 6.70 to 21.00%, displaying positively connections with the Rikenellaceae RC9 gut group. The bacterial communities associated with C. albirostris provide the basic knowledge for further microbiological studies and facilitates the conservation efforts of this vulnerable deer species.
Human activities have been a main cause of floral and faunal species extinction and loss of local and global biodiversity. Habitat and population can become fragmented and isolated under anthropogenic disturbances. In this study, we focus on the effect of human activities on the habitat and population of the giant panda (Ailuropoda melanoleuca) in the north slopes of Daxiangling Mountains, Sichuan province, China. Based on eight months of field investigation in 2004, we found that the distribution of the giant panda population has been limited to remnants of habitat due to human activities such as road construction, mining and hydropower stations. There is 100.60 km 2 area suitable for the giant panda (including moderately suitable, suitable and most suitable), which only accounts for 21.33% of the bamboo area. Based on a dispersal model COST, there were 79.94 km 2 areas (17.12%) (including moderately suitable, suitable and most suitable) for giant panda utilization in reality. Only 16.35 km 2 areas (3.5%) of total bamboo area were most suitable. The areas that suitable for panda had decreased 20.66 km 2 from 2000 in total due to people activities. The results of this study can be used to provide basic information to build nature reserve for protecting giant panda in Daxiangling Mountains.
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