Escaping from predators: a review of Neotropical lizards defence traits

Abstract

Lizards are commonly preyed by a great variety of predators, including vertebrates and invertebrates. Therefore, it is expected that lizards have developed a wide range of antipredator traits, increasing their chances of successful survival during agonistic events. Defence against predation involves two levels of behavioural strategies, commonly named primary and secondary defence traits. Primary defences relate to predator detection or interest and include as responses immobility, mimicry, aposematism, and cryptic colouration. Secondary defences occur after predator detection and attack, including traits that aim to prevent or interrupt predators. These defences encompass traits such as frightening (e.g., scratching or biting the predator), tail lashing, flouncing vigorously the body, cloacal discharge, agony vocalisations, and tail autotomy. In this review, we gathered information from 206 scientific publications, including peer-reviewed journals, short communications, scientific notes, and books. This compilation resulted in 22 defence traits, 23% passive and 77% active defences. Lizard species deal with a wide diversity of predators, but the number of field records, experiments, and antipredator studies remain scarce. We reviewed the defence traits presented by Neotropical lizards, using a phylogenetic approach in order to track evolutionary process behind these traits. Thanatosis, crypsis, and tail autotomy are symplesiomorphic for lizards, whereas venom and emetic substances are autapomorphic, and aposematism seems to be rare. We also present a novel case of defence trait where the dark colour helps lizards to be camouflaged in the burned vegetation. Our character mapping provides valuable information about the evolution of defensive traits in Neotropical lizards, combining natural history and phylogenetics. Trivial observations about any animal behaviour, including those provided by social networks and citizen science pages, might be important, and we strongly recommend that ethological observations describe the event in all possible details.