Analysis of abiotic factors associated with foam nests of Cuvier’s foam froglet (Physalaemus cuvieri) in southeastern Brazil

Climate change may have significant impacts on amphibian diversity due to alterations in microhabitat conditions where these species occurs. Understanding the abiotic factors associated with a species’ microhabitat are therefore necessary to evaluate the impact they may suffer. Amphibians are exposed to changing microhabitat conditions at multiple life stages, since reproduction and larval development of most species depend on water, whereas adults frequently depend on terrestrial habitats. Physalaemus cuvieri is a Neotropical frog that uses foam nests for reproduction that may provide some protection for tadpoles against temperature and humidity fluctuations. Herein, foam nests of P. cuvieri were studied within vegetation around a pond, with the aim of analyzing the morphometric (depth, area and volume) relationships of foam nests with abiotic factors (humidity, temperature). Humidity 2 cm above the nests was significantly greater than 2 m from the nests. Temperature, measured at different depths of the nests, was significantly reduced by up to 10 °C when compared to atmospheric air temperatures above the nests. We conclude that foam nests facilitate a protective environment for eggs by regulating temperature and humidity to acceptable levels.