Systematic Relationships of Pocket Gophers (Genus Geomys) on the Central Great Plains

Taxonomic relationships of two supposed species, Geomys bursarius and G. lutescens, on the Central Great Plains were assessed using morphometric, bacular, karyotypic, and electrophoretic analyses. Only cranial size and pelage color proved useful in differentiating between the taxa in a zone of contact in Kansas, where no indication of morphometric intergradation was found. Populations of the same taxa in a zone of contact in Nebraska were distinct not only morphometrically but also karyologically and electrophoretically; however, results from all three data sets suggested introgression. These genetic data and the lack of concordance between zones of contact in Kansas and Nebraska indicate that the two taxa should be regarded as subspecies of G. bursarius rather than distinct species.