Reply to comments by Olson et al. 2017 and Stien 2017.

Guillaume Chapron,Adrian Treves

doi:10.1098/rspb.2017.1743

Abstract

The management of large carnivores remains a contentious issue in many countries. Among the most contentious management options is ‘tolerance hunting’, or the killing of predators to increase tolerance among groups of people who do not accept the presence of these animals [1,2]. In [3,4], we used Bayesian state space models to evaluate the hypothesis that liberalizing culling of wolves changed wolf population dynamics from 1995 to 2012, and concluded it slowed growth, which we inferred was owing to increased poaching. Olson et al . [5] and Stien [6] re-visit our paper and we address their criticisms below. First, we disagree with Olson et al .'s [5] and Stien's [6] assertions that our paper ignores the literature or reports it in a biased manner. We simply disagree about the interpretation of the literature as we explain below. While they can have a different interpretation of those papers, it does not mean that ours is incorrect and Stien's [6, p. 1] phrasing ‘biased reporting of previously published results’ almost suggests intent from us to mislead the reader. Both Olson et al . [5] and Stien [6] raised the issue of density dependence analysed by Stenglein et al . [7]. In that paper, the information on density dependence relevant to our paper is in figures 3, S2.4, S2.5 and S2.6 (we cannot find reported numerical estimates on how recruitment changed during the relevant period for our study in [7]). Stenglein et al . [7, p. 5] wrote that ‘The evidence for a negative slope of the line for t > 18 was 69.0% (proportion of …

Highlights

Papers present, in our opinion, empirical evidence to support a mechanism for density dependence in the population and period under discussion
Stien [6] argues that the quadratic relationship he found for area against population size is evidence of negative density dependence
The United States Fish and Wildlife Service reported that the Wisconsin wolf population grew from minima of 746 to 866 by April 2016 [9] after all wolf-killing including tolerance hunting was barred in December 2014, or a 1-year growth of 16%, which is larger than the annual median growth during our study period

Summary

Introduction

Papers present, in our opinion, empirical evidence to support a mechanism for density dependence in the population and period under discussion. Stien [6] argues that the quadratic relationship he found for area against population size is evidence of negative density dependence. The United States Fish and Wildlife Service reported that the Wisconsin wolf population grew from minima of 746 to 866 by April 2016 [9] after all wolf-killing including tolerance hunting was barred in December 2014, or a 1-year growth of 16%, which is larger than the annual median growth during our study period.

Results

Conclusion