Chaetodipus collis

Highland Coarse-haired Pocket Mouse
(*Chaetodipus collis*)
Highland Coarse-haired Pocket Mouse (Chaetodipus collis)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Heteromyidae
Subfamily:	Perognathinae
Genus:	Chaetodipus
Binomial details
	Chaetodipus collis (W. F. Blair, 1938)
Other resources
	Full taxonomic details at MDD

The Highland Coarse-haired Pocket Mouse (Chaetodipus collis) is a medium-sized pocket mouse found in parts of the Chihuahuan Desert in New Mexico, Texas, and northern Mexico. It was considered a subspecies of Chaetodipus nelsoni, until Neiswenter et al. (2019) found evidence to elevate it to species status.

Description

From Neiswenter et al. (2019): "General effect of upper parts Tawny-Olive heavily washed with black. A distinct, Ochraceous-Buff lateral line present. Ears dusky. Underparts and feet white. Tail bicolor, blackish above, white below. … hairs on the hind legs coarser, flattened, and heavily grooved; rump spines coarser; annulations on the tail coarser...(Blair 1938:1–2)."

Museum type specimens

Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. © University of Michigan Museum of Zoology (UMMZ)

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range	Reference	Total length	Tail length	Hindfoot length	Ear length	Mass
Texas	Schmidly & Bradley (2016)	187	104	22		14–17
Texas (Trans-Pecos region)	Wilkins & Schmidly (1979)	males: 180, females: 181	males: 102, females: 102	males: 21, females: 21	males: 8, females: 8

Skull

Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. Dorsal view of the skull. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Arrows identify the interorbital width. The interparietal bone is colored yellow. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. Ventral view of the skull. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. Lateral view of the skull. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. Dorsal view of the mandible. © University of Michigan Museum of Zoology (UMMZ)
Holotype: UMMZ:Mammals:79299. Chaetodipus collis . Limpia Canyon, 4800 ft, c.1 mi NW Fort Davis, Texas. Lateral view of the left mandible. © University of Michigan Museum of Zoology (UMMZ)

Taxonomic notes

In 2019, Neiswenter et al. published: "We investigated phylogeographic diversity within the species [Chaetodipus nelsoni] using morphologic, karyotypic, and molecular data. Data from nuclear (AFLP) and mitochondrial DNA support three distinct genetic groups with minimal substructuring coincident with biogeographic barriers previously identified in the Chihuahuan Desert and drainage basins of the Altiplano. We examined the morphological and karyotypic data in light of the molecular data. The results support recognition of three species within the currently accepted widespread C. nelsoni: 1) C. nelsoni restricted to a distribution centered on the El Salado River Basin; 2) elevation of C. n. collis to species, with two subspecies: one centered on Trans-Pecos Texas, the other on the Mapimí Basin (new subspecies); and 3) recognition of a new species, C. durangae, centered on the Nazas Basin and upper Río Mezquital drainage.... As noted by Baker (1956), most specimens of C. collis are lighter in pelage color than other populations of the former C. nelsoni."

Similar species

In the USA, Chaetodipus collis is sympatric or near-sympatric with the following species of pocket mice: Chihuahuan Desert Pocket Mouse (Chaetodipus eremicus), Hispid Pocket Mouse (Chaetodipus hispidus), Rock Pocket Mouse (Chaetodipus intermedius), Plains Pocket Mouse (Perognathus flavescens), Silky Pocket Mouse (Perognathus flavus), and Merriam's Pocket Mouse (Perognathus merriami). The presence of pronounced rump spines distinguishes Chaetodipus collis from Chihuahuan Desert Pocket Mouse (Chaetodipus eremicus), Hispid Pocket Mouse (Chaetodipus hispidus), and members of the genus Perognathus. The Rock Pocket Mouse (Chaetodipus intermedius) and nelsoni are both rock-dwelling pocket mice and both have rump spines, but these may not be evident at some times (CMDBS, 2008).

Highland Coarse-haired Pocket Mouse (Chaetodipus collis) observed by Madison Gover near Alpine, Texas.
Highland Coarse-haired Pocket Mouse (Chaetodipus collis) observed by Madison Gover. The white arrow points to the subauricular spot, which is sometimes present in this species. When it is present, it is small. Above the subauricular spot is the lobed antitragus of the ear, which is helpful in differentiating this species from sympatric Perognathus. The black arrow points to one of the many rump spines, which is also helpful for differentiating from sympatric Perognathus.
Rock Pocket Mouse (Chaetodipus intermedius) photographed by Rick Overson and Laura Steger on Black Butte near the Vulture Mountains of Maricopa County, Arizona.
Arrows point to a few of the many rump spines of the Rock Pocket Mouse (Chaetodipus intermedius).

References

Baker RH. 1956. Mammals of Coahuia, México. University of Kansas Publications, Museum of Natural History 9:125–335.

Blair WF. 1938. Two new pocket-mice from western Texas. Occasional Papers of the Museum of Zoology, University of Michigan 381:1–3.

Centennial Museum and Department of Biological Sciences (CMDBS). 2008. Heteromyidae—Pocket Mice and Kangaroo Rats, The University of Texas at El Paso. [accessed 20 July 2024]. http://museum2.utep.edu/mammalogy/taxa/heteromyidae.htm

Neiswenter, SA, Hafner DJ, Light JE, Cepeda GD, Kinzer KC, Alexander LF, Riddle BR. 2019. Phylogeography and taxonomic revision of Nelson’s pocket mouse (Chaetodipus nelsoni). Journal of Mammalogy 100(6): 1847-1864.