An empirical evaluation of the African elephant as a focal species for connectivity planning in East Africa

Authors

  • Clinton W. Epps,

    Corresponding author
    1. Department of Fisheries and Wildlife, Oregon State University, Nash Hall Room 104, Corvallis, OR 97331, USA
    2. Department of Veterinary Physiology, Sokoine University of Agriculture, Box 3017, Morogoro, Tanzania
    3. Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall 3114, Berkeley, CA 94720-3114, USA
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  • Benezeth M. Mutayoba,

    1. Department of Veterinary Physiology, Sokoine University of Agriculture, Box 3017, Morogoro, Tanzania
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  • Lauren Gwin,

    1. Department of Agricultural and Resource Economics, Oregon State University, 213 Ballard Hall, Corvallis, OR 97331, USA
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  • Justin S. Brashares

    1. Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall 3114, Berkeley, CA 94720-3114, USA
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Clinton W. Epps, Oregon State University, Department of Fisheries and Wildlife, Nash Hall Room 104, Corvallis, OR 97331, USA.
E-mail: Clinton.Epps@oregonstate.edu

Abstract

Aim  Large, charismatic and wide-ranging animals are often employed as focal species for prioritizing landscape linkages in threatened ecosystems (i.e. ‘connectivity conservation’), but there have been few efforts to assess empirically whether focal species co-occur with other species of conservation interest within potential linkages. We evaluated whether the African elephant (Loxodonta africana), a world-recognized flagship species, would serve as an appropriate focal species for other large mammals in a potential linkage between two major protected area complexes.

Location  A 15,400 km2 area between the Ruaha and Selous ecosystems in central Tanzania, East Africa.

Methods  We used walking transects to assess habitat, human activity and co-occurrence of elephants and 48 other large mammal species (> 1 kg) at 63 sites using animal sign and direct sightings. We repeated a subset of transects to estimate species detectability using occupancy modelling. We used logistic regression and AIC model selection to characterize patterns of elephant occurrence and assessed correlation of elephant presence with richness of large mammals and subgroups. We considered other possible focal species, compared habitat-based linear regression models of large mammal richness and used circuit theory to examine potential connectivity spatially.

Results  Elephants were detected in many locations across the potential linkage. Elephant presence was highly positively correlated with the richness of large mammals, as well as ungulates, carnivores, large carnivores and species > 45 kg in body mass (‘megafauna’). Outside of protected areas, both mammal richness and elephant presence were negatively correlated with human population density and distance from water. Only one other potential focal species was more strongly correlated with species richness than elephants, but detectability was highest for elephants.

Main conclusions  Although African elephants have dispersal abilities that exceed most other terrestrial mammals, conserving elephant movement corridors may effectively preserve habitat and potential landscape linkages for other large mammal species among Tanzanian reserves.

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