Poaching Threatens the Establishment of a Lynx Population, Highlighting the Need for a Centralized Judiciary Approach

Raphaël Arlettaz,Sergio Vignali,Stéphane Mettaz,Elisabeth Klaus,Marc Kéry,Stefanie Roder,Fridolin Zimmermann,Guillaume Chapron,Veronika Braunisch

doi:10.3389/fcosc.2021.665000

Abstract

Illegal hunting represents a major threat to the conservation of predators, but its impact remains difficult to assess as there are strong incentives to conceal this criminal activity. Attributing declines of carnivores to poaching is therefore an important conservation challenge. We present a case study of the Eurasian lynx (Lynx lynx) in the Swiss Alps (Valais) where the current distribution range is smaller than in the recent past and population density is by ≥80% lower than in the adjacent Swiss Prealps. We tested four hypotheses to explain this lower density: (1) a too low density of camera-traps deployed for lynx surveys in Valais compared to the Prealps (methodological artifact); (2) less favorable environmental conditions around the camera-trap sites; (3) lower densities of the main prey; and (4) poaching. We estimated lynx and ungulate densities and environmental conditions at trail camera sites and could clearly reject the first three hypotheses because: (1) the survey protocol was similarly effective; (2) environmental conditions around the trapping sites in Valais were even more favorable for lynx detection than in the Prealps; and (3) prey supply was even larger in Valais. Concerning hypothesis 4, we discovered a network of illegal lynx traps (neck snares) in the main immigration corridor into Valais from the thriving adjacent lynx population in the Prealps, suggesting intense local poaching. Our findings substantiate the suspicions of long-lasting lynx poaching as a threat to the establishment and survival of the Valais population. The fact that instances of poaching were publicly known since 1995 but remained unabated for at least two decades, until the first conviction occurred, questions the commitment of local authorities to address this case of wildlife crime. Our study demonstrates the need for inquiries about poaching of top predators to be carried out at the highest levels of jurisdiction to avoid any risk of collusion between law enforcement agents and poachers.

Highlights

Protection of large predators in human dominated landscapes represents an important challenge for contemporary conservation
We evaluate four plausible hypotheses that could potentially explain the extremely low density of the lynx population in Valais—representing only 12–20% of what might reasonably be expected—as framed in the previous assessment of its status (Biollaz et al, 2016): methodological limitations and caveats linked to the lynx monitoring techniques themselves, suboptimal ecological conditions for the lynx in Valais, and high poaching pressure
Evidence for poaching of lynx in this study exclusively proves necksnaring in a key specific location, illegal hunting in other parts of Valais, probably with other methods such as guns, has been documented (Breitenmoser and Breitenmoser-Würsten, 2008)

Summary

Introduction

Protection of large predators in human dominated landscapes represents an important challenge for contemporary conservation. Large predators may interfere with economic activities, especially animal husbandry, leisure and commercial hunting (Treves and Karanth, 2003), making a smooth coexistence with humans difficult to achieve (Chapron and López-Bao, 2016; López-Bao et al, 2017). Large carnivores are declining globally (Ripple et al, 2014), some regions of the world have seen these species making an often unforeseen comeback (Chapron et al, 2014). An essential driver of such recoveries, besides an increase of prey species and more favorable public attitudes, is the legal protection of predators (Chapron et al, 2014). In the European Union, the Habitats Directive imposes limitations on legal killing of large carnivores (Epstein and Chapron, 2018)

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Conclusion