Management and harvesting constraints influence the attainment of wildlife population targets

Abstract

An increasing number of wildlife populations are the target of intensive management schemes aimed at preventing their extinction or over-abundance, both of which are detrimental to human well-being [1]. These schemes typically involve a manager, whose role is to regulate the activity of those having a direct impact on the wildlife population through legal – and sometimes illegal – harvesting activities, i.e. harvesters. Both manager and harvesters face constraints on their ability to regulate and harvest, respectively, yet how these constraints interact to affect management effectiveness is very rarely considered [2]. Using a novel generalised management strategy evaluation framework [3], we explore the manager-user constraint relationship and its impact on management success for a range of simulated and real-world examples. We show that the potential for variation in both the ability of a manager to regulate harvester behaviour and the ability of individual harvesters to affect a wildlife population shapes a landscape of management effectiveness. We further reveal that only a subset of this landscape corresponds to the successful attainment of a given management target, and that its extent may vary depending on the species in question, the stated management target (i.e. population recovery, stabilization or eradication), and the existence of time lags between monitoring and management policy change. Our work highlights the important of accounting for manager and user constraints when setting targets for and implementing wildlife management schemes.

[1] Bunnefeld, N. and Keane, A. (2014). Managing wildlife for ecological, socioeconomic, and evolutionary sustainability. Proceedings of the National Academy of Sciences, 111, 12964-12965

[2] Milner-Gulland, E. J. (2011). Integrating fisheries approaches and household utility models for improved resource management. Proceedings of the National Academy of Sciences, 108, 1741-1746.

[3] Duthie, A.B. et al. (2017). GMSE: an R package for generalised management strategy evaluation. Methods in Ecology and Evolution (in review). Preprint available on bioRxiv.