Continent-wide survey reveals massive decline in African savannah elephants.

Michael J Chase,Sam Ferreira,Patrick Omondi,Curtice R Griffin,Kelly Landen,Scott Schlossberg,Sintayehu W Djene,S.A Jeanetta Selier,Falk Grossman,Paul W Elkan,Alexis Peltier,Edward Mtarima Kohi,Robert Sutcliffe,Philippe J.C Bouché

doi:10.7717/peerj.2354

Abstract

African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants’ downward trajectory by preventing poaching and protecting habitat.

Highlights

African elephants (Loxodonta africana) play important roles in both the natural and human worlds: ecologically as a keystone species (Bond, 1994), economically as drivers of tourism (Brown Jr, 1993), and culturally as icons of the African continent (Carruthers, 2010)
Estimates of continental elephant populations range from ∼400,000 to over 630,000 with little consensus as to the actual numbers (IUCN, 2013), and estimates of poaching losses are based on models and carcass counts rather than changes in numbers of live elephants (UNEP et al, 2013; Wittemyer et al, 2014)
Across all Great Elephant Census (GEC) countries, our model showed that elephant populations increased from 1995 until approximately 2007 and began a decline that accelerated after 2010 (Fig. 2)

Summary

Introduction

African elephants (Loxodonta africana) play important roles in both the natural and human worlds: ecologically as a keystone species (Bond, 1994), economically as drivers of tourism (Brown Jr, 1993), and culturally as icons of the African continent (Carruthers, 2010). Elephant populations are threatened by poaching for ivory, human-elephant conflict, habitat loss and fragmentation, and isolation of populations (UNEP et al, 2013). A wave of poaching in the 1970s and 1980s decimated populations in many areas (Douglas-Hamilton, 1987), and a renewed poaching outbreak beginning around 2005 has led to the deaths of an estimated 30,000 elephants per year recently (UNEP et al, 2013; Wittemyer et al, 2014). Estimates of continental elephant populations range from ∼400,000 to over 630,000 with little consensus as to the actual numbers (IUCN, 2013), and estimates of poaching losses are based on models and carcass counts rather than changes in numbers of live elephants (UNEP et al, 2013; Wittemyer et al, 2014)

Methods

Results

Discussion

Conclusion