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

Abstract

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.

Notes on the reproductive biology of three Taiwanese species of the genus Kurixalus (Anura: Rhacophoridae)

“…Such selective behavior was documented in K. pollicaris (originally considered K. eiffingeri) in an experimental bamboo forest in the cloud forest zone in central Taiwan (Kam et al 1996, Kam et al 1998a, Lin et Kam 2008, Tung et al 2015. Similarly, K. eiffingeri sensu stricto from the southern Ryukyu Islands, which breeds in waterfilled tree holes and leaf axils (Ueda 1986) selects higher tree holes and holes with a larger opening angle to avoid the greater predation risk present in lower tree holes with a steeper opening (Sato et Iwai 2021).…”

“…Kam 1996, Kam et al 1998a,b, Hsu et al 2006, Lin et Kam 2008, Tung et al 2015 apply to K. pollicaris, and the data obtained for K. eiffingeri sensu lato from the southern Ryukyu Islands (e.g. Ueda 1986, Sato et Iwai 2021 refer to K. eiffingeri sensu stricto. Interestingly, a reproductive biology of an unnamed species from northern Taiwan referred to by Dufresnes et Litvinchuk (2022) as K. cf.…”