Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

The Historic Ranges of Three Equid Species in North-East Africa: A Quantitative Comparison of Environmental Tolerances

I. E. Bauer, J. McMorrow and D. W. Yalden
Journal of Biogeography
Vol. 21, No. 2 (Mar., 1994), pp. 169-182
Published by: Wiley
DOI: 10.2307/2845470
Stable URL: http://www.jstor.org/stable/2845470
Page Count: 14
  • Download ($42.00)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
The Historic Ranges of Three Equid Species in North-East Africa: A Quantitative Comparison of Environmental Tolerances
Preview not available

Abstract

The historic ranges of three equid species native to north-east Africa are analysed with respect to annual rainfall, several temperature parameters and a satellite-derived multispectral index of primary productivity. Equus africanus Fitzinger, Equus grevyi Oustalet and Equus burchelli Gray used to largely replace each other, geographically, with narrow zones of range overlap occurring between E. africanus and E. grevyi in the Awash valley, and between E. grevyi and E. burchelli in southern Ethiopia and northern Kenya. The three species are shown to succeed each other along an environmental gradient. The position of each species on this gradient and the resulting location and extent of its range are discussed. Competitive exclusion, specific adaptations and historic events are likely determinants of equid distribution. In the area of sympatry between E. grevyi and E. burchelli, mixed habitat characters as well as environmental fluctuations seem to prevent either species from excluding the other. Different social organizations of E. grevyi and E. burchelli and the resulting migratory patterns may be adaptations to the environment in their allopatric ranges; in their sympatric range they could alleviate competition.

Page Thumbnails

  • Thumbnail: Page 
169
    169
  • Thumbnail: Page 
170
    170
  • Thumbnail: Page 
171
    171
  • Thumbnail: Page 
172
    172
  • Thumbnail: Page 
173
    173
  • Thumbnail: Page 
174
    174
  • Thumbnail: Page 
175
    175
  • Thumbnail: Page 
176
    176
  • Thumbnail: Page 
177
    177
  • Thumbnail: Page 
178
    178
  • Thumbnail: Page 
179
    179
  • Thumbnail: Page 
180
    180
  • Thumbnail: Page 
181
    181
  • Thumbnail: Page 
182
    182