Fig. 1. Geographic distribution of Thomomys bottae in southwestern Colorado.
- 1. T. b. howelli
- 2. T. b. aureus
- 3. T. b. pervagus
- 4. T. b. cultellus
- 5. T. b. internatus
- 6. T. b. rubidus
In studying geographic variation, greater emphasis was placed on females than on males. As noted by Grinnell (1931:4), males vary more than females, especially in length of rostrum and associated nasal measurements.
Color terms are those of Munsell (1954). Color measurements were standardized by the use of a single 100 watt General Electric blue daylight bulb in a 12 inch white reflector suspended 24 inches above the specimen. All other light was excluded. The individual hairs of Thomomys bottae are either bicolored or tricolored. The darkness of a specimen often may be attributed to the presence of dark-tipped hairs. The color given in the description is the basic reddish or yellowish color of the hairs. The presence of a grizzled effect or a dark dorsal stripe, or any other pattern resulting from dark hairs, is noted in the remarks.
Specimens examined are listed by counties in the following order:
- Mesa
- Montrose
- San Miguel
- Dolores
- Montezuma
- La Plata
- Archuleta
- Conejos
- Chaffee
- Fremont
- El Paso
- Pueblo
- Custer
- Huerfano
- Alamosa
- Las Animas
Localities are listed from north to south within a county. If two localities lie on the same line of latitude, the western precedes the eastern. Localities omitted on the map in order to prevent overlapping of symbols are in Italics. Unless otherwise indicated, specimens are in the University of Kansas, Museum of Natural History. The following initials are used to designate specimens in other collections:
CSU—Colorado State University, Fort Collins, Colorado.
CMNH—Colorado Museum of Natural History, Denver, Colorado.
ERW—E. R. Warren Collection, Colorado College, Colorado Springs, Colorado.