Peromyscus sonoriensis
| Western Deermouse
(Peromyscus sonoriensis) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Myomorphi |
| Superfamily: | Muroidea |
| Family: | Cricetidae |
| Subfamily: | Neotominae |
| Tribe: | Peromyscini |
| Genus: | Peromyscus |
| Binomial details | |
| Peromyscus sonoriensis (Le Conte, 1853) | |
| Other resources | |
| Full taxonomic details at MDD | |
The Western Deermouse (Peromyscus sonoriensis) is a small- to medium-sized deer mouse found in a variety of habitats. Many species of deer mice are difficult to differentiate without careful measurement and examination of the molar teeth. With the help of good photographs, it may be possible to narrow the list of potential species.
Molecular studies by Bradley et al. (2019) and Greenbaum et. al (2019) indicate that Peromyscus maniculatus is a complex of multiple species. Both studies elevate some lineages within maniculatus to species status, including Peromyscus sonoriensis. However, analyses by Boria & Blois (2023) using 28,000 genome wide SNPs show Peromyscus maniculatus sonoriensis and Peromyscus maniculatus gambelii are either very recently diverged or in the process of diversification and they recommend that they should not yet be raised to distinct species. Here, we treat Peromyscus sonoriensis as a distinct species, as recommended by Bradley et al. (2019) and Greenbaum et. al (2019) and inline with the current consensus of the American Society of Mammalogists' Mammal Diversity Database. The taxonomy of the Peromyscus maniculatus species group may further change in the near future as additional studies are published. The map on the right represents the distribution of Peromyscus sonoriensis according to both Greenbaum et al. (2019) and Bradley et al. (2019). The dark green area represents the distribution according to Greenbaum et al. (2019). The light green shading covers areas that Bradley et al. (2019) included in their distribution map.
Description
From Armstrong et al. (2010): "This is a highly variable mouse, both morphologically (D. Armstrong 1972) and physiologically (Wasserman and Nash 1979). In Colorado, dorsal color ranges from grayish brown to rufous orange to pale buff. The underparts and feet are white. Juveniles are medium gray in color, darker than some adults. The ears are conspicuous but usually shorter than the hindfoot. The tail is distinctly bicolored and obviously shorter than the head and body."
Museum type specimens
-
Holotype: USNM 146/1128. Peromyscus sonoriensis. Young, sex not given. Santa Cruz, Sonora, Mexico. Collected 24–28 September 1851. Dorsal view. -
Holotype: USNM 146/1128. Peromyscus sonoriensis. Young, sex not given. Santa Cruz, Sonora, Mexico. Collected 24–28 September 1851. Ventral view.
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 |
|---|---|---|---|---|---|---|
| Colorado | Armstrong et al. (2010) | 135–180 | 57–78 | 17–21 | 14–21 | 14–27 |
| Nebraska (north-central) | Johnsgard (2020) | 130–164 | 50–71 | 19–25 | ||
| North Dakota | Seabloom et al. (2020) | 152 | 62 | 18 | 15 | 22 |
| Texas | Schmidly & Bradley (2016) | 170 | 81 | 20 | 18 (12–20) | 15–32 |
Color variation
This section shows some of the color variation present in Peromyscus sonoriensis. The location is provided for reference only. The individual shown does not necessarily represent the only color variant within the local population.
-
ASUMAC009072. Peromyscus sonoriensis. Subadult. Mohave County, Arizona. -
NEON048HL Peromyscus sonoriensis. Adult. Boulder County, Colorado. -
NEON09G00. Peromyscus sonoriensis. Subsdult. Boulder County, Colorado. -
NEON01IPF. Peromyscus sonoriensis. Adult. Logan County, Colorado. -
NEON054OK. Peromyscus sonoriensis. Adult. Weld County, Colorado. -
NEON054OK. Peromyscus sonoriensis. Adult. Riley County, Kansas. -
NEON06GRY. Peromyscus sonoriensis. Adult. Stutsman County, North Dakota. -
NEON0CPI1. Peromyscus sonoriensis. Adult. Washita County, Oklahoma. -
NEON0CYSE. Peromyscus sonoriensis. Adult. Tooele County, Utah. -
NEON01IUH. Peromyscus sonoriensis. Adult. Skamania County, Washington. Long-tailed population. -
NEON01I9Z. Peromyscus sonoriensis. Adult. Park County, Wyoming. -
NEON08ORY. Peromyscus sonoriensis. Juvenile. Park County, Wyoming.
Skull
From Armstrong et al. (2010): "The maxillary toothrow is usually less than 4 mm long (that of the white-footed mouse is often more than 4 mm)." Additionally, "the zygomatic arches of the white-footed mouse show a slight but distinct bowing compared with the straighter arches in deer mice."
The skull of the holotype for this species is heavily damaged. Skulls from other specimens are shown below.
-
NEON01I9Z. Dorsal view of the skull of Peromyscus sonoriensis. -
NEON01I9Z. Lateral view of the skull of Peromyscus sonoriensis. -
NEON01I9Z. Ventral view of the skull of Peromyscus sonoriensis. -
NEON01I9Z. Dorsal view of the lower jaw of Peromyscus sonoriensis.
Taxonomic notes
In 2019, based on mitochondrial DNA, Bradley et al. (2019) and Greenbaum et al. (2019) proposed elevating some of the monophyletic (descended from a common evolutionary ancestor or ancestral group) lineages within the P. maniculatus species group to distinct species, in addition to those species already recognized, resulting in at least 9 species within the P. maniculatus species complex. In 2023, Boria & Blois published their analyses using 28,000 genome wide SNPs, showing P. m. sonoriensis and P. m. gambelii are either very recently diverged or in the process of diversification and should not yet be elevated to distinct species.
Similar species
Comparison with Peromyscus attwateri
-
Western Deermouse (Peromyscus sonoriensis) -
Texas Deermouse (Peromyscus attwateri)
Comparison with Peromyscus boylii
-
Western Deermouse (Peromyscus sonoriensis) -
Brush Deermouse (Peromyscus boylii)
Comparison with Peromyscus crinitus
-
Western Deermouse (Peromyscus sonoriensis) -
Canyon Deermouse (Peromyscus crinitus)
Comparison with Peromyscus eremicus
The Cactus Deermouse (Peromyscus eremicus) differs from Peromyscus sonoriensis in actually and relatively longer tail, less heavily haired and less biocolored tail, body shorter rather than longer than tail, ears not fringed with white, and upper molars 1-2 without mesolophs (Hoffmeister, 1986).
-
Western Deermouse (Peromyscus sonoriensis) -
Cactus Deermouse (Peromyscus eremicus)
Comparison with Peromyscus fraterculus
-
Western Deermouse (Peromyscus sonoriensis) -
Northern Baja Deermouse (Peromyscus fraterculus)
Comparison with Peromyscus gossypinus
Comparison needed in eastern Texas, eastern Oklahoma, and Arkansas, where these two species are sympatric. Sympatric P. sonoriensis have smaller body sizes and, unlike P. gossypinus, they normally have sharply bicolored tails (Wolfe and Linzey, 1977).
-
Western Deermouse (Peromyscus sonoriensis) -
Cotton Deermouse (Peromyscus gossypinus)
Comparison with Peromyscus gratus
Comparison with Peromyscus keeni
From Naughton (2012): "While chromosomally distinct from Deer Mice [Peromyscus maniculatus (sensu lato)], there are, unfortunately, no completely reliable physical traits that will distinguish all Keen's Mice from Deer Mice in the field... The following formula using diastema length (the gap between the back of the incisors and front edge of the molars) and tail length separates the two species in the southern part of their range, including Washington State and Vancouver Island and the surrounding islands: 4.4 x length of tail (in mm) + length of mandibular diastema (in mm). Animals with a score of ≥ 436 are Keen's Mice, while those with scores of < 436 are Deer Mice. The efficacy of this formula, when applied to inland and more northerly populations has not yet been assessed, and the formula is ineffective in identifying living animals."
The following is from Zheng et al. 2003. Their analysis included northwestern populations of Peromyscus maniculatus sensu lato, which are now recognized as Peromyscus sonoriensis: "The only widely used criteria for distinguishing P. keeni and P. maniculatus in the field are tail length and the ratio of tail to head + body (Sheppe 1961; Allard et al. 1987). Allard et al. (1987) used the criterion of tail length > 96 mm to distinguish adult P. keeni (designated as P. oreas in their paper) from P. maniculatus. Our data confirmed the general validity of this criterion. In our samples, all the maniculatus individuals with tail length > 95 mm were found either in northwestern Oregon or on Vancouver Island, indicating an uneven distribution of long-tailed maniculatus individuals.... Individuals belonging to the P. keeni clade typically have longer tails and a higher tail to head + body ratio than those of the P. maniculatus clade. The absolute tail length distinguishes the keeni clade more strongly than the ratio of tail to head + body. Among individuals of the P. keeni clade, 94% had tail length ≥ 95 mm; among P. maniculatus 91% had tail length < 95 mm (Fig. 5a). Among individuals of the P. keeni clade, 88% had a tail to head + body ratio ≥ 1.10; among P. maniculatus, 81% had a tail to head + body ratio < 1.10." See the figure from Zheng et al. (2003).
-
Western Deermouse (Peromyscus sonoriensis), long-tailed population in Washington -
Northwestern Deermouse (Peromyscus keeni)
Comparison with Peromyscus labecula
From Bradley et al. (2019) describing P. labecula: "A member of the P. maniculatus species group. Phenotypically resembles other species in terms of size, coloration, and bicolored tail. Averaging smaller than P. sonoriensis and tail shorter (< 75 mm).
Comparison with Peromyscus laceianus
Comparison with Peromyscus leucopus
Peromyscus sonoriensis and Peromyscus leucopus are a pair of often co-occurring species that is notoriously difficult to differentiate in the field in certain regions of North America. Generally, Peromyscus sonoriensis has a strongly/sharply bicolored tail and a duller appearance (although it is quite variable), whereas Peromyscus leucopus has a less distinctly bicolored tail and a rich amber-brown appearance. However, these characters should be used with caution. Confidently differentiating these two species may require genetic testing. Peromyscus sonoriensis and P. leucopus can be differentiated in the lab using an AFLP-PCR (genetic) method developed by Tessier et al. (2004). A modified version that is fairly quick and inexpensive is available in the Genetic resources section.
From Armstrong et al. (2010); "The species is sometimes difficult to tell from the white-footed [Peromyscus leucopus] but usually the deer mouse has a shorter skull (greater length less than 27 mmm) and a shorter hindfoot (less than 21 mm), and the tail is more distinctly bicolored."
-
Western Deermouse (Peromyscus sonoriensis) -
White-footed Deermouse (Peromyscus leucopus)
Comparison with Peromyscus maniculatus
Comparison with Peromyscus melanotis
From Álvarez-Castañeda (2005): "Peromyscus melanotis and P. maniculatus [sensu lato, including P. sonoriensis] are extremely similar morphologically, causing considerable taxonomic confusion (Avise et al. 1979). No measurement or characteristic can be used consistently to distinguish P. maniculatus [sensu lato, including P. sonoriensis] from P. melanotis (Ramírez-Pulido 1969)."
-
Western Deermouse (Peromyscus sonoriensis) -
Black-eared Deermouse (Peromyscus melanotis)
Comparison with Peromyscus nasutus
-
Western Deermouse (Peromyscus sonoriensis) -
Northern Rock Deermouse (Peromyscus nasutus)
Comparison with Peromyscus truei
-
Western Deermouse (Peromyscus sonoriensis) -
Pinyon Deermouse (Peromyscus truei)
References
Álvarez-Castañeda, S.T., 2005. Peromyscus melanotis. Mammalian Species, (764), pp.1-4.
Armstrong DM, Fitzgerald JP, Meaney CA. 2010. Mammals of Colorado, Second Edition. Denver (CO, USA): University Press of Colorado.
Boria RA, Blois JL. 2023. Phylogeography within the Peromyscus maniculatus species group: Understanding past distribution of genetic diversity and areas of refugia in western North America. Molecular Phylogenetics and Evolution, 180, p.107701.
Boria RA, Wooldridge B, Kautt AF, Ashing-Giwa K, McFadden S, Kirby C, Edwards S, Hoekstra HE. 2026. Pleistocene climatic oscillations impact the diversification of deer mice (Peromyscus maniculatus) and the independent evolution of ecotypes. bioRxiv preprint doi: https://doi.org/10.64898/2026.01.26.699144
Bradley R, Francis JQ, Platt II RN, Soniat TJ, Alvarez D, Lindsey L. 2019. Mitochondrial DNA sequence data indicate evidence for multiple species within Peromyscus maniculatus. Special Publications, Museum of Texas Tech University.
Greenbaum IF, Honeycutt RL, Chirhart SE. 2019. Taxonomy and phylogenetics of the Peromyscus maniculatus species group. From field to laboratory: a memorial volume in honor to Robert J. Baker, 71, pp.559-575.
Johnsgard PA. 2020. Wildlife of Nebraska: a natural history. Lincoln (NE, USA): University of Nebraska Press.
Naughton D. 2012. The natural history of Canadian mammals. Toronto (ON, CA): University of Toronto Press.
Schmidly DJ, Bradley RD. 2016. The mammals of Texas. Austin (TX, USA): University of Texas Press.
Seabloom R, Hoganson JW, Jensen WF. 2020. The mammals of North Dakota. Fargo (ND, USA): North Dakota State University Press.