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RESEARCH ARTICLE
Contents Vol 35(5)

Predicting habitat suitability for the endemic mountain nyala (Tragelaphus buxtoni) in Ethiopia

Paul H. Evangelista A B D , John Norman III A , Lakew Berhanu C , Sunil Kumar A and Nathaniel Alley B
+ Author Affiliations
- Author Affiliations

A Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523-1499, USA.

B The Murulle Foundation, PO Box 1442, Fort Collins, CO 80522, USA.

C Ethiopian Wildlife Conservation Department, PO Box 386, Addis Ababa, Ethiopia.

D Corresponding author. Email: paulevan@nrel.colostate.edu

Wildlife Research 35(5) 409-416 https://doi.org/10.1071/WR07173
Submitted: 12 November 2007  Accepted: 9 May 2008   Published: 19 August 2008

Abstract

The use of statistical models to predict species distributions and suitable habitat has become an essential tool for wildlife management and conservation planning. Models have been especially useful with rare and endangered wildlife species. One such species is the mountain nyala (Tragelaphus buxtoni), a spiral-horned antelope endemic to the Ethiopian highlands. The full range of the species has never been adequately defined and recent discoveries of new populations suggest that others may exist undetected. To identify potential mountain nyala occurrences, we used classification tree analysis to predict suitable habitat using 76 climatic, topographical and vegetative variables. Three model evaluation methods showed a strong performance of the final model with an overall accuracy of 90%, Cohen’s maximised κ of 0.80 and area under the receiver operating characteristic curve (AUC) value of 0.89. Minimum temperature and maximum precipitation generally had the greatest predictive contributions to suitable mountain nyala habitat. The predicted habitat covered an area of 39 378 km2, with the majority occurring in remote forests on the southern escarpment of the Bale Mountains. Other areas within the predicted range may be too impacted by human and livestock populations to support mountain nyala; however, the model will be useful in directing future surveys for new populations while offering clues to the species historical range.

Additional keywords: classification tree, ecological niche model, habitat suitability, WorldClim.


Acknowledgements

The authors would like to thank the Ethiopian Wildlife Conservation Department and Oromia Regional Land and Natural Resource Department for their support of this important work and for sharing their survey data. We also would like to thank The Murulle Foundation for funding and logistical support; the USA Geological Survey, Fort Collins Science Center and Natural Resource Ecology Laboratory, Colorado State University, for technical support; ESRI® GIS and Mapping Software for software support; and Ethiopian Rift Valley Safaris for use of their facilities and field personnel. Additional gratitude is expressed to Banovich Wildscapes Foundation, Conklin Foundation, Dallas Ecological Foundation, R. Baker, G. Bond, A. Randell, P. Ripepi, J.C. and N.A. Roussos, A. Sackman, W. Stout, SCI Pittsburg Chapter, Shikar Safari Club and P. Swartzinski.


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