Antipredator defences, with particular relevance to European rabbits

Abstract

There has been a long history in the documentation of animal antipredator defences, yet there remain opaque areas that challenge our understanding of these defences. This thesis is divided into two parts. The first part considers outstanding confusion in the study of antipredator defences, including areas that need conceptual refinement or lack consensus. In particular, animals may often employ multiple mechanisms that are not mutually exclusive through a single or multiple behaviours, and thus, comprehensive experiments that consider multiple hypotheses for the behaviour would provide great benefit in a clearer understanding of the adaptive significance of these defence behaviours. The second part of the thesis outlines a field study of antipredator behaviour which finds that there are indeed multiple functions. Tail flagging behaviour, observed across various mammal species, serves as a signalling function in predator-prey dynamics, yet its evolutionary significance remains elusive, especially in Lagomorphs. Field observations of European rabbits and phylogenetic analysis suggest its potential roles in both inter- and intra-specific communication. Exposure of the underside of the white tail could be used as an alarm signal to warn conspecifics before the escape and as a quality advertisement signal during the escape to deter predator pursuit. Furthermore, under high local population density, the flagged tail may also contribute to the group confusion effect, further enhancing survival chances. Thus, multiple functions may be utilised with a single defence behaviour, either operating sequentially or under different contexts. This provides a good example of a potential area of confusion raised in the first part of the thesis where non-mutually exclusive mechanisms are employed with a single defence behaviour. Comprehensive studies that consider the trade-offs between these multiple functions will help elucidate the pressures shaping the evolution of these antipredator defences in animals.

Date of Award	1 Oct 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Tim Caro (Supervisor) & Innes C Cuthill (Supervisor)