Effects of climate variation on bird escape distances modulate community responses to global change

M Díaz,A P Møller,M.-L Kaisanlahti-Jokimäki,T Grim,P Tryjanowski,K Tätte,G Markó,J Jokimäki,J D Ibáñez-Alamo,F Morelli

doi:10.1038/s41598-021-92273-1

Abstract

Climate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Using 32,145 records of flight initiation distances for 229 bird species during 2006–2019 in 24 European localities, we show that FIDs decreased with increasing temperature and precipitation, as expected if foraging success decreased under warm and humid conditions. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models. This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change.

Highlights

Climate and land use are rapidly changing environmental conditions
Direct trophic interactions govern many aspects of network dynamics, and here we propose that behavioural changes involved in such trophic interactions influence how species may respond to climate change
We propose using a robust metric of predator avoidance behaviour, that involves a trade-off between avoidance of danger while ensuring the acquisition of basic needs, to investigate how animals resolve this trade-off along spatial and temporal climate gradients, 1Department of Biogeography and Global Change, Museo Nacional de Ciencias Naturales (BGC-MNCN-CSIC), c/Serrano 115bis, 28006 Madrid, Spain. 2Department of Zoology and Laboratory of Ornithology, Palacky University, 77146 Olomouc, Czech Republic. 3Behavioral Ecology Group, Department of Systematics, Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary. 4Department of

Summary

Introduction

Climate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change. FIDs are negatively related to population trends and range sizes under low levels of predation and disturbance (i.e. shorter FIDs enhance fitness in low-risk situations by allowing devotion of more time to foraging and reproductive activities), and positively under high-risk conditions, when predator avoidance is key for survival[22,23]

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Results

Conclusion