Myanmar’s semi-captive working elephant population is not sustainable without capture from the wild

Abstract

Wildlife populations in captivity are increasingly common, but captive populations often have a higher extinction risk and may require supplementation through wild-capture. Despite this, wild-capture may actually hinder long-term conservation goals by reducing remaining wild populations, and its direct and long-term indirect consequences for captive population viability are rarely addressed using longitudinal data. Here, we explore the implications of changes in wild-capture on population viability over 54 years using a multi-generational studbook of working Asian elephants from Myanmar. We show that population viability declined between 1960 and 2014 with declines in wild-capture. Wild-caught females had reduced birth rates and high mortality risk, but despite such disadvantages their capture is required to sustain the captive population. Importantly, survival in juveniles had a large influence on population viability, suggesting that targeting juvenile mortality may have a disproportionate effect on population growth. Myanmar’s working population may constitute a third of the large captive population of Asian elephants (~16,000 individuals), and sustainable management of this population is crucial for the preservation of this species. Our results highlight the need to assess the demographic consequences of wild-capture as species are increasingly managed and conserved in altered or novel environments, to ensure the sustainability of both wild and captive populations.