Poaching of protected wolves fluctuated seasonally and with non-wolf hunting

Francisco J Santiago-Ávila,Adrian Treves

doi:10.1038/s41598-022-05679-w

Francisco J Santiago-Ávila, Adrian Treves

Open Access

https://doi.org/10.1038/s41598-022-05679-w

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Journal: Scientific Reports	Publication Date: Feb 2, 2022
Citations: 6	License type: open-access

Affiliation: University of Wisconsin–Madison

Abstract

Poaching is the main cause of mortality for many large carnivores, and mitigating it is imperative for the persistence of their populations. For Wisconsin gray wolves (Canis lupus), periods of increased risk in overall mortality and poaching seem to overlap temporally with legal hunting seasons for other large mammals (hunting wolves was prohibited). We analyzed monitoring data from adult, collared wolves in Wisconsin, USA (1979–2012, n = 495) using a competing-risk approach to test explicitly if seasons during which it was legal to train hunting hounds (hounding) or hunt other large mammals (hunting) affected wolves’ hazard of cause-specific mortality and disappearance. We found increases in hazard for disappearances and documented (‘reported’) poaching during seasons with hunting, hounding or snow cover relative to a season without these factors. The ‘reported poached’ hazard increased > 650% during seasons with hunting and snow cover, which may be due to a seasonal surge in numbers of potential poachers or to some poachers augmenting their activities. Snow cover was a major environmental factor contributing to poaching, presumably through increased detection of wolves. Our study suggests poaching is by far the highest mortality hazard for wolves and reinforces the need for protections and policies targeting poaching of protected populations.

Highlights

Poaching is the main cause of mortality for many large carnivores, and mitigating it is imperative for the persistence of their populations
Research on intra-year mortality risk for Wisconsin wolves found that periods of increased risk in overall mortality and poaching overlapped with hunting seasons for other large mammals, such as white-tailed deer
For many large carnivores, which suffer from low natural mortality yet are subject to high risk of anthropogenic mortality and poaching, seasons of anthropogenic activity may be as important as natural ones in mediating cause-specific mortality and disappearance

Summary

Introduction

Poaching is the main cause of mortality for many large carnivores, and mitigating it is imperative for the persistence of their populations. The concealment of poaching (its cryptic component) contributes to its systematic u nderestimation[12,15,17,18,19], increasing concerns over the viability of large carnivore populations subject to additional sources of anthropogenic mortality[20,21,22,23] Given both its prevalence and cryptic nature, mitigating poaching seems imperative for the persistence of many large carnivore populations, including endangered ones that are not subject to hunting seasons[10,11,16,17,18,24]. For wolf populations in the US, recent research has explored the effect of reducing protections for the species on cause-specific mortality, including poaching and its cryptic variant Such studies have found an increase in poaching risk or incidence during policy time periods when species protections are reduced; i.e., when targeted lethal management by agency personnel, rather than unselective public hunting seasons, is sanctioned[17,18]. Research on intra-year mortality risk for Wisconsin wolves found that periods of increased risk in overall mortality and poaching overlapped with hunting seasons for other large mammals, such as white-tailed deer

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