Individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed Asian and African elephants

PLoS One. 2019 Sep 4;14(9):e0217326. doi: 10.1371/journal.pone.0217326. eCollection 2019.

Abstract

A recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number of welfare outcomes (stereotypic behavior, ovarian acyclicity, hyperprolactinemia, walking and recumbence, body condition, health status, serum cortisol). For this population of elephants, we used the same epidemiological methods to examine associations between those risk factors and two additional welfare outcomes, mean concentration and individual variability (CV) of fecal glucocorticoid metabolite concentrations (FGM) as indicators of stress. Results indicate that African elephants are more responsive to social stressors than Asians, and that poor joint health is a stress-related welfare problem for Asian, but not African elephants in the North American population. For both species, higher FGM concentrations were associated with zoos located at more northern latitudes, whereas lower FGM concentrations were associated with having free access to indoor/outdoor spaces, and spending more time in managed interactions with staff. Also important for captive management, elephants having diverse enrichment options and belonging to compatible social groups exhibited reduced intra-individual variability in FGM concentrations. Our findings show that aspects of the zoo environment can be potential sources of stress for captive elephants, and that there are management activities that may facilitate coping with zoo conditions. Given species differences in factors that affected FGM, targeted, species-specific management approaches likely are needed to ensure good welfare for all elephants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Zoo
  • Biomarkers
  • Elephants / metabolism*
  • Environment*
  • Feces / chemistry*
  • Female
  • Glucocorticoids / metabolism*
  • Male
  • Risk Factors
  • Seasons

Substances

  • Biomarkers
  • Glucocorticoids

Grants and funding

This work was part of a large-scale project “Using Science to Understand Zoo Elephant Welfare”, awarded to JLB, KC by a 2010 National Leadership Grant from the Institute for Museum and Library Services (IMLS) (grant no. LG-25-10-0033-10) from the U.S. Additional funding was from the Shared Earth Foundation to JLB (https://sharedearth.org). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.