PREDATION ON NATIVE ANURANS BY INVASIVE VERTEBRATES IN THE ATLANTIC RAIN FOREST, BRAZIL

Abstract

Anurans are usually preyed upon by other vertebrates, but in a few cases higher vertebrates serve as food for anuran species. This complexity in predator-prey interactions makes predicting the impacts of interactions difficult, especially when we are dealing with novel interactions imposed by non-native species. Introduced predators may have dramatic effects on resident species, which have not co-evolved with the introduced ones, since they provide a new environmental stress. On the other hand, the scarcity of studies and our consequent lack of understanding prevent us from taking the actions necessary to protect the native fauna into megadiverse places. Therefore, in the present paper we intent to provide new data on novel predator-prey interactions involving native and non-native species in the Brazilian Atlantic Rain Forest. In the first predatory event an individual of Rattus rattus was observed attempting to prey on two individuals of Rhinella icterica. In the second predatory event a tadpole of the native tree frog Hypsiboas sp. was found in the stomach contents of an individual of Micropterus salmoides. Non-native predators are one of the causes for amphibian population declines worldwide and the negative impacts of introduced vertebrates are probably more significant than we can detect. Additionally, in Brazil, information about the impacts caused by introductions of non-native species is accumulating slowly. Therefore, basic bits of evidence, as reported here, are necessary and may serve as a starting point for future investigations that explore the novel interactions and negative impacts caused by invasive species. We must improve our knowledge base and provide data regarding non-native predator-prey interactions with a view to clarify their biological aspects and to enable species conservation.