Ichioka Yukio, Kajimura Hisashi
Laboratory of Forest Protection, Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan.
Ecol Evol. 2024 Mar 5;14(3):e10926. doi: 10.1002/ece3.10926. eCollection 2024 Mar.
Temperature is essential for the survival and development of eggs. Some anurans have evolved and developed foam nesting traits, with thermal insulation considered to be among their functions. Foam-nesting frogs tend to exhibit reproductive plasticity. For example, they oviposit on both trees and the ground. How such plasticity affects foam nest function is of major relevance and is likely related to the adaptation of foam nesting frogs. However, this has not been well studied. In this study, we examined the interaction between foam nest site, foam nest function, and egg fate using the Japanese green tree frog, , and analysed how nest site differences (arboreal or terrestrial) affect the thermal function of foam nests. We compared the thermal functions of foam nests between arboreal and terrestrial oviposition sites of . We artificially replaced half of the arboreal nests with terrestrial environments and recorded temperature in and outside of the experimental terrestrial nest and original arboreal nests. We also examined egg survival and hatching rates for all the nests. The results indicated superior heat insulation in terrestrial nests, with warmer temperatures inside than outside the nests, especially at night, which led to a high egg survival rate. Therefore, terrestrial ovipositing should be valid under cold weather conditions. This may be related to the evolutionary history of oviposition site plasticity of this genus, which originally had an arboreal oviposition trait but evolved into terrestrial site use owing to global cooling. Our novel insights into the evolution and adaptivity of foam nesting and oviposition site use in make an important contribution to animal ecology.
温度对于卵的生存和发育至关重要。一些无尾目动物已经进化并发展出泡沫筑巢的特性，隔热被认为是其功能之一。泡沫筑巢的青蛙往往表现出繁殖可塑性。例如，它们在树上和地面都产卵。这种可塑性如何影响泡沫巢的功能至关重要，并且可能与泡沫筑巢青蛙的适应性有关。然而，这方面尚未得到充分研究。在本研究中，我们以日本树蛙为研究对象，考察了泡沫巢位置、泡沫巢功能和卵的命运之间的相互作用，并分析了巢位置差异（树栖或陆栖）如何影响泡沫巢的热功能。我们比较了日本树蛙树栖和陆栖产卵地点泡沫巢的热功能。我们人工将一半的树栖巢替换为陆地环境，并记录实验陆地巢和原始树栖巢内外的温度。我们还检查了所有巢中卵的存活率和孵化率。结果表明陆地巢具有更好的隔热性能，巢内温度高于巢外，尤其是在夜间，这导致了较高的卵存活率。因此，在寒冷天气条件下陆地产卵应该是可行的。这可能与该属产卵地点可塑性的进化历史有关，该属最初具有树栖产卵特性，但由于全球变冷而进化为利用陆地环境产卵。我们对日本树蛙泡沫筑巢和产卵地点利用的进化及适应性的新见解，对动物生态学做出了重要贡献。
