Choice of tree holes as oviposition sites by Kurixalus eiffingeri on Iriomote Island

Oviposition site choice affects survival and growth of offspring, particularly in frogs in which the offspring cannot move from the oviposition site. We intended to find the features of tree holes used for oviposition by Kurixalus eiffingeri on Iriomote Island. We measured eight tree hole variables to determine which should be included in the best model to explain breeding use by K. eiffingeri. Out of 32 tree holes examined, we found five that were used for oviposition. The best model included the height above the ground and angle of opening. Higher located tree holes and a larger opening angle were associated with more frequent oviposition by K. eiffingeri. This trend may be due to the higher predation risk in lower tree holes with a steeper opening. The importance of the height of the breeding site above ground was also noted in a previous study on bamboo stumps in Taiwan, but the opening angle was only salient in this study. Our study suggested that the same species in different ecosystems may use different criteria when choosing oviposition sites.