Oviposition site selection in two basin-digging Leptodactylus Fitzinger, 1826 (Anura)

Abstract

Proper nest site selection can reflect risk avoidance to offspring. We searched for oviposition site selection and features related to this behavior in the basing-digging foam-nesting Leptodactylus labyrinthicus and Leptodactylus syphax, both species have tadpoles that initially develop in terrestrial nests but complete their larval phase in water. To both species we compared environmental features of nest sites with Random Points (RPs). Nests of L. labyrinthicus were most commonly placed next to ponds, while L. syphax nests were restricted to sites bordering seasonal small streams. Discrimination between both species was reasonable (error 17%); L. syphax nests were on harder soil and more elevated points in relation to water level and L. labyrinthicus nests were most often beside water bodies with potential predators. Compared to RPs, L. labyrinthicus nests (error 30%) were more often hidden and closer to water, and L. syphax nests (error 11%) were more often hidden, in flatter terrains, in softer soils and closer to water. Even though L. labyrinthicus and L. syphax build nests in sites differing in hydric features and soil inclination/hardness, both species select hidden points, which seems to be important to avoid predation by dipteran larvae and desiccation.