Neotoma stephensi

Stephens's Woodrat
(*Neotoma stephensi*)
Stephens's Woodrat (Neotoma stephensi)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Myomorphi
Superfamily:	Muroidea
Family:	Cricetidae
Subfamily:	Neotominae
Tribe:	Neotomini
Genus:	Neotoma
Binomial details
	Neotoma stephensi E. A. Goldman, 1905
Other resources
	Full taxonomic details at MDD

The Stephens's Woodrat (Neotoma stephensi) is a small woodrat found most frequently in pinyon-juniper habitat where there are rocks.

Description

From Armstrong et al. (2010): “Stephen's woodrat is small and pale yellow to buff-gray in color. The belly and throat are white, the hairs of the throat gray at their bases. The tail is indistinctly bicolored, with the hairs relatively long and slightly bushy at the tip.”

From Hoffmeister (1986): “A species of Neotoma of small size but with a bushy tail, some hairs in the throat area in most populations with dark pigment in the basal part (not white-throated).” Additionally, “dusky coloration extends down the top of hind foot one-fourth to one-third the distance below the ankle, underparts are usually suffused with an ochraceous or buffy wash.”

Museum type specimens

Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902.

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
Arizona (Kearns Canyon and Jadito)	Hoffmeister (1986)	males: 281–333 (n=11); females: 274–317 (n=13)	males: 112–144 (n=11); females: 115–149 (n=13)	males: 30–33 (n=11); females: 29–33 (n=13)	males: 27–30 (n=11); females: 25–28 (n=13)
Arizona (vicinity of Kingman and Hualapai Mtns.)	Hoffmeister (1986)	males: 283–337 (n=17); females: 264–329 (n=17)	males: 120–153 (n=17); females: 106–148 (n=17)	males: 30–34 (n=17); females: 30–34 (n=17)	males: 22–29 (n=17); females: 22–30 (n=17)
Colorado	Armstrong et al. (2010)	280–333	112–144	30–33	27–30

Skull

From Jones and Hildreth (1989): "The antero-medial fold of M1 [first upper molar] is usually absent or shallow. The second loph of M3 [third upper molar] is long and narrow, extending diagonally across the tooth. The postero-labial fold of M3 terminates posterior to the lingual fold and is directed postero-medially. The lingual fold of m3 [third lower molar] is as deep as or deeper than the labial fold. The rostrum is narrow; nasals are truncate posteriorly, rarely sharply pointed. The posterior extensions of the premaxillaries rarely expand posteriorly. The supraorbital ridges remain lateral as they continue forward to the rostrum. In other species, the supraorbital ridges approach the midline terminating almost in line with the posterior extensions of the premaxillaries (Hoffmeister and de la Torre, 1960).

Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Dorsal view of the skull.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Ventral view of the skull.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Lateral view of the skull.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Dorsal view of the mandible.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Lateral view of the left mandible.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult. Upper molars.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult. Lower molars.

Habitat

Similar species

Comparison with Neotoma albigula

From Hoffmeister (1986): "N. stephensi differs from N. albigula in having a shorter baculum less flared at the base and with a shorter cartilaginous tip, usually some hairs in the throat region have the basal part darkly pigmented, rostrum narrower, and posterior tips of nasals usually truncate rather than sharply pointed."

Stephens's Woodrat (Neotoma stephensi) photographed by Rick Overson and Laura Steger in Arizona. ©Rick Overson
White-throated Woodrat (Neotoma albigula) photographed by Rick Overson and Laura Steger in Arizona. ©Rick Overson
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Dorsal view of the skull.
Holotype: USNM 186485. Neotoma albigula albigula. Adult male. Southwest corner of Grant (Hidalgo), New Mexico. Collected 12 April 1886. Dorsal view of the skull.

Comparison with Neotoma cinerea

From Hoffmeister (1986): "The bushy-tailed N. cinerea may be confused with the semi-bushy tailed N. stephensi. This is especially true in northeastern Arizona where the N. cinerea is considerably smaller. N. cinerea differs from N. stephensi in northeastern Arizona in larger size, both externally and cranially; the hind foot (if accurately measured) in adult and subadult males is 37 mm or more rather than 33 mm or less, in females, 36 mm or more rather than 33 mm or less; greatest length of animal's skull with the second lingual fold on M1 not reaching the alveolus in males is 45 mm or more rather than 42 mm or less, in females, 43.5 mm or more rather than 42 mm or less; in basilar length, in males 36 mm or more rather than 35 mm or less, in females, 36 mm or more rather than 34.5 mm or less; alveolar length of maxillary toothrow longer, 8.6 mm or more rather than less, numerous other size differences of the skull..." Additionally, the antero-medial fold of the first upper molar (M1) is usually absent or shallow in N. stephensi, whereas in N. cinerea the anteromedial flexus of the anteroloph of each M1 is deeply notched (Jones and Hildreth, 1989; Smith, 1997).

Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902.
Holotype: USNM 208968. Neotoma cinerea lucida. Adult female. Charleston Peak, Charleston Mountains, Clark County, Nevada. Collected 1 July 1915. Dorsal view of the skin.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult. Upper molars.
Holotype: USNM 208968. Neotoma cinerea lucida. Adult. Upper molars. Arrows point to the anteromedial flexus of the anteroloph of each upper molar (M1), which is deeply notched.

Comparison with Neotoma devia

A taxonomic update has been applied to the following comparison from Hoffmeister (1986): "N. devia differs from N. stephensi in having a less bushy tail, baculum much larger (and this is evident when it is everted but not even cleaned or prepared), second loph in M3 [third upper molar] is more nearly transverse, nasals more pointed posteriorly, interorbital region narrower, and dorsal surface of the hind feet in non-melanistic specimens more whitish."

Arizona Woodrat (Neotoma devia)
Holotype: USNM 226376. Neotoma devia. Adult female. Tanner Tank, Painted Desert, Coconino County, Arizona. Collected 27 July 1917. Dorsal view of the skull.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult female. Hualpai (Hualapai) Mountains, Mohave County, Arizona. Collected 1 July 1902. Dorsal view of the skull.
Holotype: USNM 226376. Neotoma devia. Adult. Upper molars. Note that the second loph in M3 [third upper molar] is more nearly transverse than in Neotoma stephensi.
Holotype: USNM 117466. Neotoma stephensi stephensi. Adult. Upper molars. The second loph in M3 [third upper molar] is more diagonal than transverse.

Comparison with Neotoma lepida

From Hoffmeister (1986): N. lepida differs from N. stephensi in having a less bushy tail, baculum much longer (and this is evident when it is everted but not when cleaned or prepared), second loph in M3 is more nearly transverse, nasals are more pointed posteriorly, interorbital region narrower, and dorsal surface of hind feet in non-melanistic specimens more whitish."

Holotype: USNM 25739. Neotoma lepida lepida. Arrows point to the second loph in each third upper molar (M3), which are nearly transverse.
Holotype: USNM 117466. Neotoma stephensi stephensi. Upper molars. The second loph of M3 (third upper molar) is long and narrow, extending diagonally across the tooth.
Holotype: USNM 25739. Neotoma lepida lepida. Arrows point to the interorbital width, which is narrower than in N. stephensi.
Holotype: USNM 117466. Neotoma stephensi stephensi. ADorsal view of the skull.

References

Armstrong DM, Fitzgerald JP, Meaney CA. 2010. Mammals of Colorado, Second Edition. Denver (CO, USA): University Press of Colorado.

Goldman EA. 1905-02-02. Twelve new wood rats of the genus Neotoma. Proceedings of the Biological Society of Washington 18:27-33.

Hoffmeister DF, De La Torre L. 1960. A revision of the wood rat Neotoma stephensi. Journal of Mammalogy 41:476-491.

Hoffmeister DF. 1986. Mammals of Arizona. Tucson (AZ, USA): University of Arizona Press.

Jones C, Hildreth NJ. 1989. Neotoma stephensi. Mammalian Species (328): 1-3.

Smith FA. 1997. Neotoma cinerea. Mammalian Species (564):1-8.