Genetic Variation in Pronghorn from West Texas

Abstract

We assessed genetic variation in 65 North American pronghorn (Antilocapra americana) from 6 geographically isolated populations in west Texas by protein electrophoresis. Five of 24 presumptive genetic loci were polymorphic; heterozygosity (H) ranged from 0.012 to 0.046 (T = 0.027). Unweighted pair group method analysis (UPGMA) clustering of Rogers' (1972) distance values indicated close affinities between the large Upper Concho Valley herd and 4 of the 5 Trans-Pecos populations. The Marathon Basin herd was significantly distinct from the other 5 herds and translocation of pronghorn into this area is not recommended. Application of genetic information is essential to current management involving translocation of individuals between isolated populations and conservation of genetic variation. For example, undocumented translocation events could be resolved using genetic techniques. Moreover, a genetic study designed to address the biogeographic history of North American pronghorn would provide a standard by which to evaluate the effects of translocation efforts. J. WILDL. MANAGE. 53(4):890-896 Pronghorn are endemic to North America with a distribution that extends north to southern Alberta and Saskatchewan, south to the southern limits of the Mexican Plateau, west to California, and east to the eastern limit of arid grasslands in the central plains states (Hall 1981). In west Texas, pronghorn occur in inter-mountain grasslands throughout the Trans-Pecos Region and in a few isolated panhandle populations. Five subspecies of pronghorn have been described by Hall (1981) and O'Gara (1978); 2 of these (American pronghorn [A. a. americana] and Mexican pronghorn [A. a. mexicana]) were proposed to occur in Texas. However, Hall (1981) reported that all pronghorn in Texas were Mexican pronghorn, except the northern panhandle populations which were designated as American pronghorn. O'Gara (1978) described the range of American pronghorn in Texas from the northern panhandle, the Upper Concho Valley, and a small population in west Texas. O'Gara (1978) restricted Mexican pronghorn to the Big Bend area of west Texas with the remaining populations of unknown status. Historically, designation and distribution of pronghorn subspecies was based on morphological characteristics (Merriam 1901). Taxonomic status of pronghorn subspecies has been further complicated by historical and/or recent translocation of American pronghorn into ranges of other subspecies (O'Gara 1978). We examined genetic relationships and patterns of genetic variation of populations of pronghorn from west Texas. Taxonomic determinations require information regarding the degree of isolation between taxa and knowledge of the variation among different subspecies and is beyond the scope of this study. However, the extent of genetic variation among pronghorn populations can provide insight into the taxonomic differentiation and effects of transloca-