Playbacks of Predator Vocalizations Reduce Crop Damage by Ungulates

Anna Widén,Michael Clinchy,Fredrik Widemo,Navinder J Singh,Liana Y Zanette,Joris P.G.M Cromsigt,Annika M Felton,Dries P.J Kuijper,Tim R Hofmeester

doi:10.2139/ssrn.3928315

Abstract

Wild ungulates are a major consumer of agricultural crops in human dominated landscapes. Across Europe, ungulate populations are leading to intensified human-wildlife conflicts. At the same time, ungulates play a vital role in the structuring and functioning of ecosystems, and are also highly appreciated for recreational hunting. Thus, managers often face the challenge of maintaining the benefits of having thriving ungulate populations while simultaneously minimizing their negative impacts. Broadcasting playbacks of predator vocalizations (e.g. dogs barking, wolves howling or humans talking) could potentially be used to induce fear and thereby displace or steer behavior of ungulates from conflict-prone sites resulting in reduced visitation and foraging time and consumption. Predator playback experiments in wilderness areas have repeatedly been demonstrated to reduce the preys´ resource use and impacts on the surrounding landscape, but this has not been tested in agricultural fields where human-ungulate conflicts are most pronounced.. We responded to this need by conducting a predator playback experiment in multiple crop fields in southern Sweden, where multiple ungulate species (fallow deer, roe deer, red deer, moose, wild boar) coexist, using a novel integrated camera trap – speaker system (ABRs) that broadcasts sounds of choice when a camera is triggered by an ungulate. Predator playbacks (wolf, dog, human) reduced deer patch use and crop damage on wheat fields more than playbacks of control sounds (owl, goose, raven). Our results confirm findings from previous studies in wilderness areas, and demonstrate that broadcasting predator playbacks using ABRs may provide an effective tool to reduce crop damage at the scale and duration of our study.

Highlights

Wild ungulates can have strong effects on their environment, and in human-dominated landscapes this may lead to conflicts with human land use such as agriculture (Reimoser and Putman, 2014)
To test for a possible detection difference between the different camera models and recording types of the Automated Behavioral Response system (ABR) and regular CTs, we compared patch use between ABRs and regular CTs using the data from pre-playback weeks with a Linear mixed effect model (LMM)
The response variable was patch use and fixed factor was camera type with two levels, field ID was added as random intercept

Summary

Introduction

Wild ungulates can have strong effects on their environment, and in human-dominated landscapes this may lead to conflicts with human land use such as agriculture (Reimoser and Putman, 2014). Ungulate numbers and distribution are increasing across Europe (Apollonio et al, 2010b; Linnell et al, 2020; Thulin et al, 2015) due to better conser vation practices, wildlife management actions and increased availability of forage arising from agriculture and forestry practices (Ferretti and Lovari, 2014; Presley et al, 2019). Across Europe, these increasing populations lead to increased crop damage, affecting production and incomes in agriculture (Reimoser and Putman, 2014). Compensation for crop damage by wildlife represents 35% of the total global agricultural compensation (Ravenelle and Nyhus, 2017) and in some European countries reaches up to 13 million euro annually (Linnell et al, 2020). Agricultural im pacts of ungulates, such as wild boar (Sus scrofa), fallow deer (Dama dama) and red deer (Cervus elaphus) are seen as an increasing problem (e.g. Apollonio et al, 2010a; Bleier et al, 2017; Marchiori et al, 2012; Menichetti et al, 2019; Schley and Roper, 2003)

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