DOI: 10.5061/dryad.f68m0
title: Data from: Harvesting wildlife affected by climate change: a modelling and management approach for polar bears

description: The conservation of many wildlife species requires understanding the
 demographic effects of climate change, including interactions between
 climate change and harvest, which can provide cultural, nutritional or
 economic value to humans. We present a demographic model that is based on
 the polar bear Ursus maritimus life cycle and includes density-dependent
 relationships linking vital rates to environmental carrying capacity (K).
 Using this model, we develop a state-dependent management framework to
 calculate a harvest level that (i) maintains a population above its
 maximum net productivity level (MNPL; the population size that produces
 the greatest net increment in abundance) relative to a changing K, and
 (ii) has a limited negative effect on population persistence. Our
 density-dependent relationships suggest that MNPL for polar bears occurs
 at approximately 0·69 (95% CI = 0·63–0·74) of K. Population growth rate at
 MNPL was approximately 0·82 (95% CI = 0·79–0·84) of the maximum intrinsic
 growth rate, suggesting relatively strong compensation for human-caused
 mortality. Our findings indicate that it is possible to minimize the
 demographic risks of harvest under climate change, including the risk that
 harvest will accelerate population declines driven by loss of the polar
 bear's sea-ice habitat. This requires that (i) the harvest rate –
 which could be 0 in some situations – accounts for a population's
 intrinsic growth rate, (ii) the harvest rate accounts for the quality of
 population data (e.g. lower harvest when uncertainty is large), and (iii)
 the harvest level is obtained by multiplying the harvest rate by an
 updated estimate of population size. Environmental variability, the sex
 and age of removed animals and risk tolerance can also affect the harvest
 rate. Synthesis and applications. We present a coupled modelling and
 management approach for wildlife that accounts for climate change and can
 be used to balance trade-offs among multiple conservation goals. In our
 example application to polar bears experiencing sea-ice loss, the goals
 are to maintain population viability while providing continued
 opportunities for subsistence harvest. Our approach may be relevant to
 other species for which near-term management is focused on human factors
 that directly influence population dynamics within the broader context of
 climate-induced habitat degradation.
description: Chukchi Sea ice
 dataSea-ice data are
 provided in two text files: "Chukchi Sea ice data.txt" and
 "Southern Beaufort Sea ice data.txt". The data and methods to
 process them are described in the main text of Regehr et al. (2017) and
 the Supporting Information Appendix S3. Please see "Sea ice
 METADATA.txt" for further details.Sea ice
 METADATA.txtSouthern Beaufort Sea
 ice dataSea-ice data are
 provided in two text files: "Chukchi Sea ice data.txt" and
 "Southern Beaufort Sea ice data.txt". The data and methods to
 process them are described in the main text of Regehr et al. (2017) and
 the Supporting Information Appendix S3. Please see "Sea ice
 METADATA.txt" for further details.Sea ice
 METADATA.txt