Climate Effects on Prey Vulnerability Modify Expectations of Predator Responses to Short- and Long-Term Climate Fluctuations

Aïssa Morin,Simon Chamaillé-Jammes,Marion Valeix

doi:10.3389/fevo.2020.601202

Abstract

Climate changes affect the distribution and abundance of organisms, often via changes in species interactions. Most animals experience predation, and a number of models have investigated how climate fluctuations can influence predator–prey dynamics by affecting prey abundance through changes in resource availability. However, field studies have shown that prey vulnerability is a key feature determining the outcome of predator–prey interactions, which also varies with climatic conditions,viachanges in prey body condition or in habitat characteristics (e.g. vegetation cover). In this theoretical work, we explore, with large mammals of African savannas in mind, how the interplay between climate-induced changes in prey abundance and climate-induced changes in prey vulnerability affects the immediate and long-term responses of predator populations. We account for prey body condition and habitat effects on prey vulnerability to predation. We show that predictions on how predator abundance responds to climate fluctuations differ depending on how climate influences prey vulnerability (habitat characteristics vs. prey body condition). We discuss how species traits influence the relative importance of the different sources of vulnerability. For example, our results suggest that populations of cursorial predators (such as spotted hyaenas) are expected to fare better than populations of ambush predators (such as African lions) in African ecosystems that will be characterised by an aridification. This study highlights the importance of understanding, and accounting for, the vulnerability factors associated to a given predator–prey pair, and improves our comprehension of predator–prey relationships in a changing climate.

Highlights

The Earth’s climate is changing rapidly, largely because of human activities (IPCC, 2014b)
In scenario 1, i.e. when climatic conditions influenced prey abundance only and not prey vulnerability, the population growth rate of predators was not influenced by the specific climatic condition of the year (Figure 4A)
In the three other scenarios, i.e. when climatic conditions influenced prey vulnerability, either through changes in prey body condition or through changes in habitat characteristics or both, the population growth rate of predators 1 year was influenced by the specific climatic condition of the year

Summary

Introduction

The Earth’s climate is changing rapidly, largely because of human activities (IPCC, 2014b). Climate changes already have ecological impacts and are, or will soon be, a major driver of species dynamics. Inouye et al, 2000; Moyes et al, 2011) or behaviour (Candolin and Wong, 2012). Most studies on the impacts of climate changes have focussed on describing changes in population distribution and abundance Even though these changes can sometimes emerge from the direct effect of climate on individuals, they often result from cascading effects occurring through biotic interactions, such as trophic interactions Understanding how climate changes will affect species through their biotic interactions is fundamental to grasp the full picture of the impacts of climate changes

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Discussion

Conclusion