Peromyscus californicus
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California Deermouse
(Peromyscus californicus) | |
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Range | |
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Taxonomic classification | |
Order: | Rodentia |
Suborder: | Supramyomorpha |
Infraorder: | Myomorphi |
Superfamily: | Muroidea |
Family: | Cricetidae |
Subfamily: | Neotominae |
Tribe: | Peromyscini |
Genus: | Peromyscus |
Binomial details | |
Peromyscus californicus (Gambel, 1848) |
Description
From Merritt (1978): "Peromyscus californicus is the largest species of the genus in the United States. Total length is 220 to 285 mm; tail is longer than head and body, commonly indistinctly bicolored, and well-haired, but the annulations are not thoroughly concealed. Color is geographically variable, generally blackish brown above, sides ochraceous-tawny, venter pale olive gray to buffy brown (Osgood, 1909). Pelage is long and lax."
From Ceballos (ed., 2014): "Peromyscus californicus is a large-sized mouse. The dorsal coloration varies geographically, but in general it is dark brown on the back and ochraceous on the sides. Its coat is long and loose, and the tail is hairy with scaly rings."
Venter is pale to whitish; buffy pectoral spot is present in some individuals. Feet are white. Tail is slightly bicolored, possesses scaly annulations, and is about as long as head-body length.
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 |
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California | Jameson & Peeters (2004) | 220–285 | 117–156 | 24–31 | 20–26 | 33–55 |
not reported | Merritt (1978) | 220–285 | 117–156 | 24–31 | 20–27 | 33.2–54.4 (multiple citations, see reference) |
Skull
From Merritt (1978): "The skull is large and the braincase well-inflated; tympanic bullae are large and inflated. Molars are robust, no accessory cusps are on M1; upper molars typically lack both lophs and styles, whereas lower molars may possess these structures; well-developed ectostylid is often present, and low ectolophid on m1; occasional subspecific variation of lophs and styles was reported by Hooper (1957:19).... greatest length of skull, 28.1 to 32.1; basilar length, 21 to 25.8; zygomatic width, 13.5 to 16.2; interorbital constriction, 4.3 to 5.1; length of nasals, 10.2 to 12.4; shelf of bony palate, 3.9 to 5.1; length of palatine slits, 5.3 to 6.9; diastema, 7 to 8.4; postpalatal length, 10.2 to 12.6; and length of maxillary toothrow, 4 to 5.1 m."
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This illustration of the right upper molar M2 from Hooper (1957) is shown to assist with identifying structures of the upper molars. In Peromyscus californicus, no accessory cusps are on M1 and upper molars typically lack both lophs and styles (Merritt, 1978). -
This illustration of the left lower m2 molar from Hooper (1957) is shown to assist with identifying structures which may be present on the lower molars of Peromyscus californicus.
Similar species
Comparison with Peromyscus boylii
From Fargo & Laudenslayer (1995) for oak woodlands of the southern Sierra Nevada in Fresno County, California: "Most identifying characteristics of the two dominant Peromyscus species, brush mouse (P. boylii) and California mouse (P. californicus) overlapped considerably. Weight, body length, tail length, hind foot length, dorsal tail-stripe width, and ear length were usually sufficient for accurate species identification. Hind foot length and dorsal tail-stripe width were the most reliable of the identification criteria examined. For hind foot length, no significant difference was found between juveniles and adults within each species. Hind foot lengths overlapped slightly between species, ranging from 20 to 25 mm for brush mice and 24 to 28 mm for California mice. Dorsal tail-stripe width had the lowest overlap between species. All of the brush mice had dorsal tail-stripes less than or equal to half the tail circumference, and 98 percent of the California mice had dorsal tail-stripes greater than half. Use of hind foot length and dorsal tail-stripe width as key field identifiers was an expedient and accurate approach for distinguishing these two species."
Comparison with Peromyscus truei
From Hoffmeister (1981): "Peromyscus truei occurs with P. californicus in parts of its range and differs from it in overall smaller size, shorter hindfoot, smaller skull and shorter toothrow, presence rather than absence of mesolophs of the first and second upper molars, and in differences in the number of kinds of chromosomes."
References
Ceballos G, editor. 2014. Mammals of Mexico. Baltimore (MD, USA): Johns Hopkins University Press.
Fargo RJ, Laudenslayer WF. 1995. Morphological differences between two white-footed mice, Peromyscus boylii and Peromyscus californicus, in oak woodlands of Fresno county, California. 1995 Transactions of the Western Section of the Wildlife Society 31: 58-62. Link
Hoffmeister DF. 1981. Peromyscus truei. Mammalian Species (161): 1-5.
Hooper ET. 1957. Dental patterns in mice of the genus Peromyscus. Miscellaneous Publications University of Michigan Museum of Zoology 99:1-59.
Jameson EW, Peeters HJ. 2004. Mammals of California (No. 66). Berkeley (CA, USA): University of California Press.
Merritt JF. 1978. Peromyscus californicus. Mammalian Species (85):1-6.
Osgood WH. 1909. Revision of the mice of the American genus Peromyscus. North American Fauna 28:1.