No trade-offs in interspecific interference ability and predation susceptibility in newt larvae.

Monika Hloušková,Veronika Kršáková,Monika Balogová,Lumír Gvoždík

doi:10.1002/ece3.4465

Abstract

Coexistence of species with similar requirements is allowed, among others, through trade‐offs between competitive ability and other ecological traits. Although interspecific competition is based on two mechanisms, exploitation of resources and physical interference, trade‐off studies largely consider only species’ ability to exploit resources. Using a mesocosm experiment, we examined the trade‐off between interference competition ability and susceptibility to predation in larvae of two newt species, Ichthyosaura alpestris and Lissotriton vulgaris. In the presence of heterospecifics, L. vulgaris larvae slowed somatic growth and developmental rates, and experienced a higher frequency of injuries than in conspecific environments which suggests asymmetrical interspecific interference. During short‐term predation trials, L. vulgaris larvae suffered higher mortality than I. alpestris. Larvae of the smaller species, L. vulgaris, had both lower interference and antipredator performance than the larger I. alpestris, which suggests a lack of trade‐off between interference competition ability and predator susceptibility. We conclude that interference competition may produce a positive rather than negative relationship with predation susceptibility, which may contribute to the elimination of subordinate species from common habitats.

Highlights

Local coexistence among taxa sharing the same resources may occur through trade-offs between their ecological traits
L. vulgaris larvae in heterospecific groups grew slower than larvae reared under the absence of interspecific interactions (F1,9 = 9.46, p = 0.01; Figure 2c)
Under the absence of heterospecifics, L. vulgaris larvae experienced a lower incidence of injuries than in their presence (F1,9 = 18.93, p = 0.002; Figure 2e)

Summary

| INTRODUCTION

Local coexistence among taxa sharing the same resources may occur through trade-offs between their ecological traits. While the trade-off between exploitative competition ability and predation susceptibility has been extensively studied on both a theoretical and empirical basis (Holt, Grover, & Tilman, 1994; Leibold, 1996; Skelly, 1995; Peacor & Werner, 2001; Kuang & Chesson, 2008; but see Murrell & Juliano, 2013), how interference competition is linked with predation susceptibility is little investigated (Cothran, Henderson, Schmidenberg, & Relyea, 2013) This is a nontrivial issue because interference competition is common among species (Grether et al, 2009). Larger I. alpestris larvae should be more active foragers to cover their higher energy demands, which increase their visibility to visually oriented predators (Werner & Anholt, 1993; Werner & McPeek, 1994) In this case, the competitive ability should be negatively associated with predation susceptibility in this system

| MATERIALS AND METHODS

| DISCUSSION

Findings

CONFLICT OF INTEREST