Spatiotemporal distribution dynamics of elephants in response to density, rainfall, rivers and fire in Kruger National Park, South Africa
Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
Aim: African elephants are ecosystem engineers. As such, their long‐term patterns of
distribution and abundance (i.e., space‐use intensity) will influence ecosystem structure
and function. We elucidate these patterns for bull versus herd groups, by analysing
the spatiotemporal dynamics of an increasing elephant population in relation to
key ecological drivers: rainfall, distance to major rivers and time since last fire.
Significant changes to the long‐term patterns of elephant density and group‐type
probabilities are identified and explained.
Location: Kruger National Park, South Africa.
Methods: Using almost three decades of census records (1985–2012), we applied
Multiple Point Process Models to assess the influence of rainfall, rivers and fire in
shaping elephant space‐use. Significant changes to the long‐term patterns of elephant
density and group type were also identified using kernel density estimates
and the spatially varying probability of encountering either bull or herd group.
Results: Bull and herd groups are no longer clearly segregated as available empty
space becomes more limited. Bull and herd groups have dichotomous resource selection
functions, in that bulls concentrate in areas receiving lower rainfall but more
frequent fires while herds concentrate in higher rainfall areas experiencing less frequent
fires. Both bull and herd groups concentrate closer to major rivers, emphasizing
rivers as important spatial drivers. Overall, densities increased most significantly
closer to rivers and in areas experiencing fewer fires. Fire was also a strong agent of
group‐type change, as the probability of finding bulls, contrary to herds, significantly
increased as fire return periods shortened.
Main conclusions: Elephant distribution and abundance patterns have homogenized
in response to increased space limitations, with group‐specific, fire‐driven distribution
patterns emerging overtime. Results herein should be used to help manage elephant
space‐use through the establishment of possible refuge areas and the
development of more empirical research into elephant impacts in future.
Description
CITATION: MacFadyen, S., et al. 2019. Spatiotemporal distribution dynamics of elephants in response to density, rainfall, rivers and fire in Kruger National Park, South Africa. Diversity and Distributions, 25(6):880-894, doi:10.1111/ddi.12907.
The original publication is available at https://onlinelibrary.wiley.com
The original publication is available at https://onlinelibrary.wiley.com
Keywords
African elephant -- South Africa -- Kruger National Park, African elephant -- South Africa -- Management, Spatiotemporal, Elephants -- Conservation -- Africa, Southern, African elephant populations, Elephants -- Behavior -- Africa, Southern
Citation
MacFadyen, S., et al. 2019. Spatiotemporal distribution dynamics of elephants in response to density, rainfall, rivers and fire in Kruger National Park, South Africa. Diversity and Distributions, 25(6):880-894, doi:10.1111/ddi.12907