Pocket gophers of the genus Geomys are common inhabitants of many habitats throughout most of the state of Nebraska. Because the taxonomic history of Geomys has undergone numerous changes through the years, these pocket gophers have been the subjects of ongoing taxonomic and distributional studies and in more recent years genetic studies to understand relationships among populations. In order to gain deeper insight into the relationships among these taxa of Geomys, we intensively collected specimens from areas where chromosomal races were thought to form contact zones. Results from examination of genetic (chromosomes, mitochondrial cytochrome-b gene sequences, and nuclear interphotoreceptor retinoid-binding protein gene sequences), morphometric, and pelage coloration data revealed 2 areas of hybridization between taxa of Geomys in Nebraska. The 1st of these corresponded to the Oakdale vicinity in Antelope and Madison counties in northeastern Nebraska and the 2nd corresponded to Lincoln County in southwestern Nebraska. The taxonomic implications of our study support the recommendations from earlier studies performed in other areas of the geographic range of Geomys. Specifically, in Nebraska we recognize 3 species: G. bursarius majusculus in eastern Nebraska, G. lutescens in the Sand Hills and adjacent areas of central and western Nebraska, and G. jugossicularis halli in southwestern Nebraska. The exact geographic distributions and relationships of these species within Nebraska and the surrounding states remain to be determined in detail.
- Genetic isolation
- Hybrid zone
- Interphotoreceptor retinoid-binding protein gene
- Mitochondrial cytochrome-b gene