摘要: Male-male vocal competition is critical for mating success in anuran species; however, it remains unknown that how males regulate their competitive strategies dynamically during competition because calling is highly time-consuming, energetically demanding and likely to increase predation risks Since different parts of calls will encode different information on for vocal communication, we hypothesized that competitive strategies of male frogs may be modulated by the temporal and spectral features of different call notes. To test this hypothesis, the natural advertisement calls (OC), its modified versions with the first call note replaced by white noise (WN) or other notes and with the fifth call note replaced by WN, were played back to the Anhui tree frogs (Rhacophorus zhoukaiyae). Results showed that 1) males produced more competitive calls in response to acoustic stimuli compared to their baseline calling during silence; and 2) males emitted more non-overlapping calls compared to overlapping calls in response to the acoustic stimuli These results are consistent with the idea that males are flexible to acoustic signals and their competition strategies are modulated dynamically by social contexts.

摘要: How nutritional conditions during early development affect an organism's phenotype at adulthood is still poorly understood despite a plethora of research on developmental plasticity. The environmental matching hypothesis predicts that individuals will have high fitness providing that their adult environment matches what they experienced during development. In contrast. the silver spoon hypothesis predicts that individuals who obtain better developmental resources will be generally superior. Here we tested these two hypotheses and examined the underlying hormonal mechanisms by manipulating the early dietary protein content of African clawed frogs (Xenopus laevis) for a year with a 2x2 factorial experimental design. We found that only a low-protein food during development enhanced the vocal competition ability of male X. laevis, and that vocal dominance was associated with higher cortisol levels but not related with testosterone content. These results were not congruent with the environmental matching' hypothesis or with the silver spoon hypothesis, suggesting the behavioral plasticity during development is more complex than our expectation in amphibians.

摘要: Attendance patterns are a key factor affecting sexual selection and mating systems in lek-breeding species. However, there are few systematic studies on attendance patterns in lek-breeding anurans. In this study, we monitored a population of Omei treefrogs (Rhacophorus omeimontis) for four consecutive years to reveal in detail the effects of attendance patterns on mating systems. We found that (1) female nightly attendance was affected by male nightly attendance, and operational sex ratios (determined by male and female nightly attendance) ultimately determined the extent of female polyandry (2) males surviving more than one breeding season maintained high chorus attendance and mating success, suggesting that male chorus attendance is a good predictor of male genetic quality; (3) the distributions of male mating success were not significantly different from a Poisson distribution, indicating a random mating pattern; and male mating success was not related to body size (size-assortative mating was not evident) but was significantly correlated with chorus attendance. Since the chorus attendance is a predictor of male genetic quality, females performing random mating were more likely to mate with more frequently present males and could therefore gain indirect benefits from mating with higher-than-average quality males, thereby producing good offspring without incurring the significant costs involved in prolonged searching for, and assessing males. Our systematic survey on the relationship between attendance patterns and the lek mating system in R. omeimontis could help us better understand in-depth anuran lek mating systems.

摘要: The calling activity of anurans is influenced by environmental variables and calls produced by syntopic amphibians, among other variables. Some variables have a strong influence, such as temperature and predation dilution, while others may have a periodical influence such as the moon cycle. Here, we hypothesised that the calling activity of the Suweon treefrog, Dryophytes suweonensis, is restricted by specific environmental variables but reinforced by the calling activity of specific syntopic anurans. Within the criteria set by the experimental design, D. suweonensis calling activity was significantly influenced by moon phase, temperature, date, time to sunset and the calling activity of Pelophylax nigromaculatus and D. japonicas. These variables are expected to be related to chorus size, predation, breeding phenology and competition, suggesting a broad plasticity in the calling activity of the species.