Even I have done some research and have found the following to indicate the "Plains" zebra population is very hard to differentiate among subspecies.
Taxonomy [top]
Kingdom Phylum Class Order Family
ANIMALIA CHORDATA MAMMALIA PERISSODACTYLA EQUIDAE
Scientific Name: Equus quagga
Species Authority: Boddaert, 1785
Infra-specific Taxa Assessed:
See Equus quagga ssp. quagga
Common Name/s:
English Plains Zebra, Burchell's Zebra, Common Zebra, Painted Zebra
Synonym/s:
Equus burchelli (Gray, 1824) [orth. error]
Equus burchellii
Equus burchellii Schinz, 1845
Taxonomic Notes: The Plains Zebra exhibits a morphological and genetic cline from north to south across its range (Groves and Bell 2004, Lorenzen 2008). Research has now firmly established that the Extinct Quagga is a subspecies of the Plains Zebra (Rau 1978, Higuchi et al. 1984, George and Ryder 1986, Leonard et al. 2005). However, this view is in opposition to some morphological evidence (e.g., Bennett 1980, Klein and Cruz-Uribe 1999).
Groves and Bell (2004) recognized six subspecies, based on coat patterns, skull metrics, and the presence or absence of a mane and of the infundibulum on the lower incisors (intergrades are observed). A recent genetic study analyzed 17 Plains Zebra populations, representing five of the six subspecies recognized by these authors (Lorenzen et al. 2008). The study found very little differentiation among populations. In fact, populations across the entire species distribution range were less differentiated than Namibian populations of Hartmann's Mountain Zebra. The five sampled Plains Zebra subspecies, which included the extinct Quagga, could not be distinguished with the genetic markers used and no genetic structuring was found indicative of distinct taxonomic units. The molecular data represented a genetic cline and was differentiated along an east-to-south gradient in agreement with the progressive increase in body size and reduction in stripes towards the south. This is consistent with the overlapping morphological parameters and geographical distribution of subspecies reported in literature. Hence, the subspecies splits based on the morphological cline may be arbitrary, but are useful from a management perspective.
Assessment Information [top]
Geographic Range [top]
Range Description: Plains Zebra range from southern Sudan and southern Ethiopia, east of the Nile River, to southern Angola and northern Namibia and northern South Africa (formerly ranging south of the Orange and Vaal Rivers to the Cape) (Hack et al. 2002; Klingel in press). They are now extinct in two countries in which they formerly occurred: Burundi and Lesotho. There is no information on their status in Angola, where they may also be extinct.
The six morphologically defined subspecies are distributed as follows (following Groves and Bell 2004, and Klingel in press):
E. q. crawshaii(Crawshay's Zebra) occurs in Zambia, east of the Luangwa River, Malawi, south-eastern Tanzania from Lake Rukwa east to Mahungoi, and Mozambique as far south as the Gorongoza district;
E. q. borensis ranges in north-west Kenya, from Guas ngishu and Lake Baringo, to the Karamoja district of Uganda and south-east Sudan, east of the Nile River to the northern limit of the species at 32ï½°N;
E. q. boehmi (Grant's Zebra or Boehm's Zebra) is found in Zambia, west of the Luangwa River, west to Kariba, Shaba Province of DR Congo north to Kibanzao Plateau; Tanzania north from Nyangaui and Kibwezi into south-west Uganda, south-west Kenya as far as Sotik, and east Kenya, east of the Rift Valley, into southern Ethiopia and perhaps to the Juba River in Somalia.
E. q. chapmani (Chapman's Zebra) ranges from north-east South Africa, from about 24ï½°S, 31ï½°E, north to Zimbabwe, west into Botswana at about 19ï½°S, 24ï½°E, the Caprivi Strip in Namibia, and southern Angola;
E. q. burchellii (Burchell's Zebra) formerly occurred north of the Vaal/Orange Rivers, extending north-west via southern Botswana to Etosha National Park and the Kaokoveld, south-east to KwaZulu-Natal and Swaziland. It is now extinct in the middle of its range. E.b. antiquorum is now included in this subspecies;
E. q. quagga (Quagga) occurred in the former Cape Province, south of the Orange and Vaal Rivers and west of the Drakensberg. Now extinct.
Countries:
Native:
Botswana; Congo, The Democratic Republic of the; Ethiopia; Kenya; Malawi; Mozambique; Namibia; Rwanda; Somalia; South Africa; Sudan; Swaziland; Tanzania, United Republic of; Uganda; Zambia; Zimbabwe
Possibly extinct:
Angola
Regionally extinct:
Burundi; Lesotho
Range Map: Click here to open the map viewer and explore range.