Tail autotomy works as a pre-capture defense by deflecting attacks.

William L Allen,Laura A Naidenov

doi:10.1002/ece3.7213

Abstract

Caudal autotomy is a dramatic antipredator adaptation where prey shed their tail in order to escape capture by a predator. The mechanism underlying the effectiveness of caudal autotomy as a pre‐capture defense has not been thoroughly investigated. We tested two nonexclusive hypotheses, that caudal autotomy works by providing the predator with a “consolation prize” that makes it break off the hunt to consume the shed tail, and the deflection hypothesis, where the autotomy event directs predator attacks to the autotomized tail enabling prey escape. Our experiment utilized domestic dogs Canis familiaris as model predator engaged to chase a snake‐like stimulus with a detachable tail. The tail was manipulated to vary in length (long versus short) and conspicuousness (green versus blue), with the prediction that dog attacks on the tail should increase with length under the consolation‐prize hypothesis and conspicuous color under the deflection hypothesis. The tail was attacked on 35% of trials, supporting the potential for pre‐capture autotomy to offer antipredator benefits. Dogs were attracted to the tail when it was conspicuously colored, but not when it was longer. This supports the idea that deflection of predator attacks through visual effects is the prime antipredator mechanism underlying the effectiveness of caudal autotomy as opposed to provision of a consolation prize meal.

Highlights

Autotomy, the ability of an animal to shed a body part without any external force, is an extreme and dramatic antipredator adaptation (Emberts et al, 2019; Maginnis, 2006)
It is most frequently studied in lizards where tail shedding (“caudal autotomy”; Figure 1) in response to threat is present in 15/18 lizard families (Bateman & Fleming, 2009)
To date experiments have either used static models without the ability to shed their tail (Bateman et al, 2014; Castilla et al, 1999; Fresnillo et al, 2015; Heninger et al, 2020; Watson et al, 2012), or investigated autotomy occurring after predators had already captured the lizard's tail in laboratory setting (Cooper & Vitt, 1985), so there is no direct evidence that pre-capture autotomy is effective because of deflection

Summary

| INTRODUCTION

The ability of an animal to shed a body part without any external force, is an extreme and dramatic antipredator adaptation (Emberts et al, 2019; Maginnis, 2006). To date experiments have either used static models without the ability to shed their tail (Bateman et al, 2014; Castilla et al, 1999; Fresnillo et al, 2015; Heninger et al, 2020; Watson et al, 2012), or investigated autotomy occurring after predators had already captured the lizard's tail in laboratory setting (Cooper & Vitt, 1985), so there is no direct evidence that pre-capture autotomy is effective because of deflection. Many other relationships between autotomy traits and life stage, ecotype, sex, behavior, and body size have been identified (Hawlena, 2006; Ortega et al, 2014; Telemeco et al, 2011) While this body of evidence demonstrates that autotomy is tightly linked to costs for the prey, it is not yet clear how important the energetic reward of an autotomized tail is to predators (Emberts et al, 2019; Humphreys & Ruxton, 2018),. This setup allowed the tail to detach from the body at the point in the chase when both strings went taut, simulating an autotomy event

| METHODS

Findings

| DISCUSSION