To cut a long tail short: A review of lizard caudal autotomy studies carried out over the last 20 years

Abstract

Caudal autotomy, the ability to shed the tail, is common in lizards as a response toattempted predation. Since Arnold’s substantial review of caudal autotomy as adefence in reptiles 20 years ago, our understanding of the costs associated with tailloss has increased dramatically. In this paper, we review the incidence of caudalautotomy among lizards (Reptilia Sauria) with particular reference to questionsposed by Arnold. We examine tail break frequencies and factors that determineoccurrence of autotomy in natural populations (including anatomical mechanisms,predation efficiency and intensity, microhabitat preference, sex and ontogeneticdifferences, as well as intraspecific aggression). We also summarize the costsassociated with tail loss in terms of survivorship and reproduction, focusing onpotential mechanisms that influence fitness (i.e. locomotion costs, behaviouralresponses and metabolic costs). Finally, we examine the factors that may influencethe facility with which autotomy takes place, including regeneration rate, bodyform and adaptive behaviour. Taking Arnold’s example, we conclude withproposals for future research.