Physiological indicators of stress in African forest elephants (Loxodonta africana cyclotis) in relation to petroleum operations in Gabon, Central Africa
Article first published online: 8 JUL 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Diversity and Distributions
Volume 14, Issue 6, pages 995–1003, November 2008
How to Cite
Munshi-South, J., Tchignoumba, L., Brown, J., Abbondanza, N., Maldonado, J. E., Henderson, A. and Alonso, A. (2008), Physiological indicators of stress in African forest elephants (Loxodonta africana cyclotis) in relation to petroleum operations in Gabon, Central Africa. Diversity and Distributions, 14: 995–1003. doi: 10.1111/j.1472-4642.2008.00509.x
- Issue published online: 15 OCT 2008
- Article first published online: 8 JUL 2008
- Conservation physiology;
- disturbance ecology;
- faecal DNA;
- faecal glucocorticoid metabolites;
- Gamba Complex of Protected Areas;
- oil fields
Aim Human activities are major determinants of forest elephant (Loxodonta africana cyclotis) distribution in Gabon, but the types and intensity of disturbance that elephants can tolerate are not known. We conducted dung surveys within the Gamba Complex of Protected Areas in SW Gabon to examine (1) the feasibility of noninvasive faecal analyses for monitoring stress physiology, and (2) the influence of petroleum operations on stress levels in forest elephants.
Location Gabon, Central Africa.
Methods We identified multiple dung piles from the same individual by matching their eight-locus microsatellite genotypes, and measured faecal concentrations of glucocorticoid metabolites as an indicator of stress in areas subject to different levels of disturbance: (1) Loango National Park (2) an ‘industrial corridor’ dominated by oil fields, and (3) a nearby area of human settlements.
Results We obtained unique microsatellite genotypes and faecal glucocorticoid metabolite (FGM) concentrations for 150 forest elephant individuals, which is the largest hormonal data set for wild African forest elephants to date. Adults exhibited higher mean FGM concentrations than juveniles, and in contradiction of our expectations of chronic stress around oil fields, elephants in Loango National Park exhibited significantly higher FGM concentrations than elephants in the industrial corridor.
Main conclusions We argue that forest elephants in the industrial corridor of the Gamba Complex have become acclimated to oil fields, resulting in part from oil company regulations that minimize stressful interactions between elephants and petroleum operations. Our findings for a flagship species with substantial ecological requirements bode well for other taxa, but additional studies are needed to determine whether oil operations are compatible over their life span with rain forest ecosystems in Central Africa.