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Inter-generational change in African elephant range use is associated with poaching risk, primary productivity and adult mortality.

Authors :
Goldenberg SZ
Douglas-Hamilton I
Wittemyer G
Source :
Proceedings. Biological sciences [Proc Biol Sci] 2018 May 30; Vol. 285 (1879).
Publication Year :
2018

Abstract

Repeated use of the same areas may benefit animals as they exploit familiar sites, leading to consistent home ranges over time that can span generations. Changing risk landscapes may reduce benefits associated with home range fidelity, however, and philopatric animals may alter movement in response to new pressures. Despite the importance of range changes to ecological and evolutionary processes, little tracking data have been collected over the long-term nor has range change been recorded in response to human pressures across generations. Here, we investigate the relationships between ecological, demographic and human variables and elephant ranging behaviour across generations using 16 years of tracking data from nine distinct female social groups in a population of elephants in northern Kenya that was heavily affected by ivory poaching during the latter half of the study. Nearly all groups-including those that did not experience loss of mature adults-exhibited a shift north over time, apparently in response to increased poaching in the southern extent of the study area. However, loss of mature adults appeared to be the primary indicator of range shifts and expansions, as generational turnover was a significant predictor of range size increases and range centroid shifts. Range expansions and northward shifts were associated with higher primary productivity and lower poached carcass densities, while westward shifts exhibited a trend to areas with higher values of primary productivity and higher poached carcass densities relative to former ranges. Together these results suggest a trade-off between resource access, mobility and safety. We discuss the relevance of these results to elephant conservation efforts and directions meriting further exploration in this disrupted society of a keystone species.<br /> (© 2018 The Author(s).)

Details

Language :
English
ISSN :
1471-2954
Volume :
285
Issue :
1879
Database :
MEDLINE
Journal :
Proceedings. Biological sciences
Publication Type :
Academic Journal
Accession number :
29794044
Full Text :
https://doi.org/10.1098/rspb.2018.0286