Scapanus occultus

Southern Broad-footed Mole
(*Scapanus occultus*)
Southern Broad-footed Mole (Scapanus occultus)
Range
Taxonomic classification
Order:	Eulipotyphla
Suborder:	Erinaceota
Superfamily:	Talpoidea
Family:	Talpidae
Subfamily:	Talpinae
Tribe:	Scalopini
Genus:	Scapanus
Binomial details
	Scapanus occultus J. Grinnell & Swarth, 1912
Other resources
	Full taxonomic details at MDD

The Southern Broad-footed Mole (Scapanus occultus) is a dark mole restricted to southern California and northern Baja California, Mexico.

Description

From Palmer (1937) comparing occultus with subspecies of Scapanus latimanus, including Scapanus anthonyi (a species endemic to Baja California in Mexico): "Diagnosis. Size: Small. Color: Generally pale and brownish. Color. As observed in specimens from the vicinity of Los Angeles: In fresh winter pelage, near Fuscous above; slightly lighter below. In worn winter pelage, between Benzo Brown and Drab or near Saccardo's Umber above; Hair Brown below. In fresh summer pelage, Drab above; near Mouse Gray below. In worn summer pelage, between Buffy Brown and Olive Brown above; near Drab below. Specimens in worn summer pelage from Walker Basin, Kern County, are paler and more brassy, palest Buckthorn Brown to Dresden Brown above; Buffy Brown below; darkest Saccardo's Umber toward Sepia above."

Museum specimens

Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Dorsal view of the skin.
Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Ventral view of the skin.

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
California (Fresno Co.)	Verts & Carraway (2001)	females: 140–160 (n=4); males: 156–170 (n=4)	females: 26–32 (n=4); males: 32–38 (n=4)	females: 19–21 (n=4); males: 19–20 (n=4)
California (Los Angeles Co.)	Palmer (1937); in Verts & Carraway (2001)	females: 140–161 (n=6); males: 132–157 (n=7)	females: 29–34 (n=6); males: 27–34 (n=7)	females: 18–20 (n=6); males: 18–21 (n=7)

Skull

From Palmer (1937), comparing occultus with subspecies of Scapanus latimanus, including Scapanus anthonyi (a species endemic to Baja California in Mexico): "Skull: Smaller, with relatively narrow, tapering rostrum; relatively broad interorbital region; small narrow orbits; relatively broad, deep braincase."

Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Dorsal view of the skull.
Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Ventral view of the skull.
Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Lateral view of the skull.
Holotype MVZ:Mamm:2369. Scapanus occultus. Female. Santa Ana Canyon, Orange County, California. Collected 20 September 1908. Lateral view of the right mandible.

Taxonomic notes

From Álvarez-Castañeda & Cortes-Calva (2021): "Based on our phylogenetic analysis and its morphological characteristics (Allen 1893; Jackson 1915; Huey 1936; Yates and Salazar-Bravo 2005), we support that S. anthonyi is a different species from S. latimanus. Additionally, we propose that specimens known as S. latimanus occultus (including S. l. grinnelli) from southern California and northern Baja California peninsula should be considered as a distinct species (S. occultus) different from S. latimanus from central and north California and from S. anthonyi inhabiting San Pedro Mártir. Therefore, we consider that the genus Scapanus contains five species that should be recognized as S. anthonyi, S. latimanus, S. occultus, S. orarius, and S. townsendi... We did not perform a morphometric analysis of the craniodental measurements because this previously was reported by Yates and Salazar-Bravo (2005). Yates and Salazar-Bravo (2005) reported statistical differentiation in morphological characters between S. l. occultus and S. anthonyi separated by a distance > 50 km. In addition, they found significant differences between S. l. occultus and S. l. latimanus sensus (Yates and Salazar-Bravo 2005), with S. l. occultus being smaller overall. No specimens of S. l. occultus and S. l. latimanus have been collected in sympatry and in the two areas where S. l. occultus and S. l. latimanus occur, namely the southern part of Sierra Nevada and northern portion of Santa Barbara, it appears that S. l. occultus occurs in lower altitudes, and S. l. latimanus at higher altitudes."

Similar species

Key to the species of Scapanus

Once considered a subspecies of Scapanus latimanus, phylogenetic analysis by Álvarez-Castañeda & Cortes-Calva (2021) supported the recognition of Scapanus latimanus occultus as a species separate from Scapanus latimus. From Álvarez-Castañeda & Cortes-Calva (2021): "No specimens of S. l. occultus and S. l. latimanus have been collected in sympatry and in the two areas where S. l. occultus and S. l. latimanus occur, namely the southern part of Sierra Nevada and northern portion of Santa Barbara, it appears that S. l. occultus occurs in lower altitudes, and S. l. latimanus at higher altitudes... Scapanus occultus can be differentiated from S. latimanus in its smaller size and longer and wider skull (Yates and Salazar-Bravo 2005). Some specimens have fewer than seven unicuspid teeth, but only on a single side of the mandible or maxilla."

Southern Broad-footed Mole (Scapanus occultus) observed by Justin M. Wood in San Bernardino National Forest, California.
Northern Broad-footed Mole (Scapanus latimanus) observed by jabbott in Willits, California.

References

Allen JA. 1893. On a collection of mammals from San Pedro Martir region of Lower California. Bulletin American Museum Natural History 5:181-202.

Álvarez-Castañeda ST, Cortes-Calva P. 2021. Revision of moles in the genus Scapanus. Therya 12(2): 275-281. https://doi.org/10.12933/therya-21-1174 (https://www.scielo.org.mx/scielo.php?pid=S2007-33642021000200275&script=sci_arttext)

Huey LM. 1936. Notes on the moles of Lower California, México. Journal of Mammalogy 17:166-167.

Jackson HHT. 1915. A review of the American moles. North American Fauna 38:1-100.

Palmer FG. 1937. Geographic variation in the mole Scapanus latimanus. Journal of Mammalogy 18(3):280-314. https://www.jstor.org/stable/1374204

Yates TL, Salazar-Bravo J. 2005. Revision of the Scapanus latimanus, with the revalidation of a species of Mexican mole. Pp. 489-506, in Contribuciones mastozoológicas en Honor a Bernardo Villa (Sánchez-Cordero, V., and R. Medellín, eds.). Instituto de Biología, UNAM, Instituto de Ecología UNAM. Ciudad de México, México.