Predation and the evolution of complex oviposition behaviour in Amazon rainforest frogs

Area of Science:

• Ecology
• Evolutionary Biology
• Herpetology

Background:

• Amphibians in the Amazon rainforest commonly use terrestrial oviposition with free-living aquatic larvae.
• Microhabitat diversity may maintain diverse reproductive strategies in amphibians.

Purpose of the Study:

• Investigate factors associated with microhabitat diversity and amphibian reproductive modes.
• Examine desiccation, fish predation, competition, and water quality as drivers of terrestrial oviposition.

Main Methods:

• Studied 11 waterbodies in the central Amazonian rainforest.
• Conducted predation experiments with fish, tadpoles, and beetle larvae.
• Correlated terrestrial oviposition with environmental factors and predation indices.

Main Results:

• Fish did not prey on anuran eggs; tadpoles and beetle larvae were significant egg predators.
• Terrestrial oviposition correlated positively with egg predation pressure and negatively with fish biomass.
• High fish biomass protected aquatic anuran eggs from predation.

Conclusions:

• Predation by fish on anuran eggs is unlikely to be a primary driver of terrestrial oviposition.
• Egg predation pressure from tadpoles and beetles is a significant selective force favoring terrestrial oviposition.
• Terrestrial oviposition functions as a predator avoidance strategy against non-fish egg predators.