Are we adequately assessing the demographic impacts of harvesting for wild‐sourced conservation translocations?

Abstract

AbstractTranslocation, the human‐mediated movement of organisms from one area to another, is a popular tool in conservation management. Wild‐caught individuals are more likely to persist following release than those sourced from captive breeding. However, this benefit of obtaining individuals from wild populations must be carefully weighed against the potential harm to the viability of source populations. In this structured review, we assess the peer‐reviewed primary literature that addresses wild‐sourced translocation programs. We aim to determine what proportion of studies make a priori estimates of the impact of harvesting on source populations, what proportion provide quantitative evidence of demographic trends in source populations following harvest, and which methods are being used to assess impacts of harvesting on source populations. Of 292 articles reviewed, we identified just 32 instances (11%) where impact on the source population was estimated. The proportion of studies that assess impacts on source populations in a given year has not increased over time. However, studies that make explicit a priori comparisons of alternative harvesting strategies are becoming more frequent. We propose a standardized framework for reporting on management of translocation source populations. Published summaries of wild‐sourced translocations should include clear conservation goals, a description of the methods used to assess potential impact, an a priori justification based on evidence for the chosen harvesting strategy, an estimated timeline for recovery and a summary of postremoval population trends to assess the efficacy of a priori impact assessment. Routinely reporting impacts of harvesting on source populations will inform management when source sustainability is uncertain, improve transparency and increase the likelihood of successful conservation for many threatened species.