Poaching lowers elephant path tortuosity: implications for conservation

Festus W Ihwagi,Guillaume Bastille‐Rousseau,Albertus G Toxopeus,Iain Douglas‐Hamilton,Tiejun Wang,Andrew K Skidmore

doi:10.1002/jwmg.21688

Festus W Ihwagi, Guillaume Bastille‐Rousseau + Show 4 more

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https://doi.org/10.1002/jwmg.21688

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Abstract

ABSTRACTPoaching is the most immediate threat to African elephants (Loxodonta africana). Several continental‐wide surges in poaching have occurred since the latter half of the twentieth century, and the latest surge occurred from 2007 to 2012. The behavioral responses of elephants to poaching risk has not been studied widely because of a lack of high‐resolution movement data collected simultaneously with verified causes of mortality. We managed to collate 2 such datasets from 2004 to 2013. We studied the spatial‐temporal changes in movement behavior of 11 elephants in their core areas. Past studies have focused on elephant movement along corridors. We tested for the effect of poaching risk on their path straightness (i.e., tortuosity) while controlling for other environmental and human activities in the landscape using a set of generalized linear mixed models. To test for temporal variation of tortuosity, we used a time‐series linear model. Elephants turned less frequently while they were in poaching locations and at times with a high level of poaching activity, even though their speed did not change. The variation of tortuosity is a good indicator of differences in poaching risk as perceived by the elephants, which could complement patrol‐based anti‐poaching efforts by wildlife managers, especially in remote, inaccessible landscapes. © 2019 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society

Highlights

Inversely proportional to the efficiency of the orientation mechanism involved, unless major obstacles abound (Benhamou 2004)
In a landscape dominated by humans, in which different core areas for elephants lie in distinct land management units that have different levels of poaching, we would expect elephants to change their short‐ term movement behavior as they forage in full vigilance
Environmental factors influenced the tortuosity of all the elephants we studied, and, in addition, human factors influenced those elephants that were outside the rhino sanctuaries

Summary

Introduction

Inversely proportional to the efficiency of the orientation mechanism involved, unless major obstacles abound (Benhamou 2004). By increasing speed when traversing unsafe areas, switching from the day to night‐time travel, and avoiding settlements during the daytime (Douglas‐Hamilton et al 2005, Graham et al 2009, Wittemyer et al 2017, Ihwagi et al 2018) These studies focused on the alteration of speed when elephants venture out of their (presumably safer) core areas. In a landscape dominated by humans, in which different core areas for elephants lie in distinct land management units that have different levels of poaching, we would expect elephants to change their short‐ term movement behavior as they forage in full vigilance. Change in behavior is an aspect that movement speed alone would probably not capture

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