Antipredator mechanisms of post-metamorphic anurans: a global database and classification system

Abstract

A crucial step in any ethological study is to distinguish and classify the observed behavior into categories. The literature on anuran antipredator mechanisms is largely scattered and descriptive due to the opportunistic nature of the observations and the lack of a simple, widely accepted classification scheme. We propose an explanatory classification system of antipredator mechanisms for post-metamorphic anurans (i.e., juveniles and adults) based on a thorough review of the literature and observations made during fieldwork and in the laboratory since 1970. In addition, we provide a freely available global database on antipredator mechanisms of post-metamorphic anurans. The classification system is composed of 12 antipredator mechanisms and 28 variations distributed into three stages of defense (avoid detection, prevent attack, and counterattack). The database comprises 650 species and 39 families providing a unique opportunity to investigate ecological and evolutionary questions regarding antipredator mechanisms of anuran. We provide a general overview of geographic, taxonomic, and phylogenetic patterns found in the database. Both our studies and that of our colleagues added 70 species to the database. The number of publications on antipredator mechanisms increased substantially after the year 2000. We hope to spark a renewed interest in antipredator mechanisms of post-metamorphic anurans to understand further the evolution of predator–prey interactions. Predation is a phenomenon of great ecological and evolutionary significance. Hence, the study of antipredator mechanisms may provide some of the most fascinating answers to questions regarding species “struggle for existence.” Based on extensive fieldwork, laboratory observations, and a thorough literature survey, we propose a classification system of antipredator mechanisms for anurans and provide a database of antipredator mechanisms elicited by frogs. We describe each mechanism, discuss the variations, and provide images for most antipredator mechanisms.