Perognathus alticolus
| White-eared Pocket Mouse
(Perognathus alticolus) | |
|---|---|
| Range | |
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| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Castorimorphi |
| Superfamily: | Geomyoidea |
| Family: | Heteromyidae |
| Subfamily: | Perognathinae |
| Genus: | Perognathus |
| Subgenus: | Cricetodipus |
| Binomial details | |
| Perognathus alticolus Rhoads, 1894 | |
| Other resources | |
| Full taxonomic details at MDD | |
The White-eared Pocket Mouse (Perognathus alticolus) occupies arid shrub and forest communities in two small areas in southern California.
Description
From Wilson et al. (2016): "Male White-eared Pocket Mice are significantly larger than females. Pelage is soft, fine, and full with no hint of spines orstiff bristles; posterior one-half of sole of hindfoot has sparse covering of short hairs; and tail is short and not tufted. Unlike most other silky pocket mice, the White-eared Pocket Mouse has lobed antitragus of ear pinna, and tail is slightly crested for distal one-third (with dark hairs). The White-eared Pocket Mouse is medium-sized to large-sized for the genus but smaller than its close relatives, the Great Basin Pocket Mouse [Perognathus mollipilosus] and the Columbia Plateau Pocket Mouse (P. parvus). Hairs on inner surface of ear pinna are white or yellowish. Dorsal pelage is yellowish brown and heavily blackish lined, dorsal hairs are plumbeous at their bases for 75 % of their length, lateral line usually is faintly expressed, and under parts are white. Tail is the same length or slightly longer than head-body length and bicolored."
Museum specimens
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Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. -
Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893.
Distribution
From Best (1994): "The white-eared pocket mouse occupies arid shrub and forest communities in southcentral California, in the transverse ranges of Kern and Los Angeles counties, and the San Bernardino Mountains, San Bernardino Co. (Williams et al., 1993) at elevations 1,500 m (Grinnell, 1933; Stephens, 1906). P. a. alticolus is known only from arid Ponderosa pine (Pinus ponderosa) communities in the vicinity of Little Bear Valley and Strawberry Peak, San Bernardino Mountains, San Bernardino Co., California. P. a. inexpectatus occupies arid shrub-steppe communities in the Tehachapi Mountains of southcentral California, from the vicinity of Tehachapi Pass, Kern Co., on the northeast to the vicinity of Mount Pinos, Ventura Co., on the northwest, and Elizabeth and Quail lakes, Los Angeles Co., on the south (Williams et al., 1993)."
External measurements
Museum help needed!
Skull characters
From Best (1994): "The auditory bullae are relatively small, the posterior borders of the mastoid bullae are about even with the most posterior part of the supraoccipital, and the mastoid bulla forms small indentations in the border of the exoccipital at the back of the skull. The ascending branches of the supraoccipital are relatively broad and the interorbital region is broad."
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Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. Dorsal view of the skull. -
Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. Ventral view of the skull. -
Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. Lateral view of the skull. -
Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. Dorsal view of the mandible. -
Holotype: ANSP 1615. Perognathus alticolus. Male. San Bernardino Mountains, San Bernardino County, California. Collected 22 September 1893. Lateral view of the left mandible.
Similar species
From Best (1994): "Perognathus alticolus can be distinguished from P. parvus [and P. mollipilosus; however neither are sympatric with P. alticolus] by its smaller average size, white or yellowish hairs on the inner surface of the pinna, a tail with more blackish hairs on the distal one-third of the dorsal surface, and a more pronounced indentation of the mastoid bulla into the border of the exoccipital. P. alticolus can be distinguished from all other species of Perognathus by its lobed antitragus and more prominent crest on the distal portion of the tail (Williams et al., 1993). Cranially, P. alticolus may be distinguished from P. flavescens and P. inornatus by the well-defined separation of the auditory bullae ventrally. The lower premolar of P. alticolus is similar to that of P. inornatus, but the mastoids of P. inornatus are much larger than those of P. alticolus. P. alticolus is larger than P. flavescens and P. inornatus, less yellow than P. flavescens, and more lined with black than P. inornatus (Rhoads, 1894)."
References
Best TL. 1994. Perognathus alticolus. Mammalian Species (463): 1-4. https://doi.org/10.2307/3504273
Grinnell J. 1933. Review of the Recent mammal fauna of California. University of California Publications in Zoology (40): 71-234.
Rhoads SN. 1894. Descriptions of new species of North American mammals with remarks on species of the genus Perognathus. Proceedings of the Academy of Natural Sciences of Philadelphia 45(3):404-412.
Stephens F. 1906. California mammals. San Diego (CA, USA): The West Coast Publishing Company.
Williams DF, Genoways HH, Braun JK. 1993. Taxonomy. Pp, 38-196, in Biology of the Heteromyidae (HH Genoways and JH Brown, eds.). Special Publication, The American Society of Mammalogists (10) :1-719.
Wilson DE, Lacher Jr TE, Mittermeier RA. 2016: Heteromyidae. In: Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I. Barcelona: Lynx Edicions: 170-233, ISBN: 978-84-941892-3-4, DOI: 10.5281/zenodo.6611160