250.

San Lorenzo Deermouse

Peromyscus interparietalis

French: Péromyscus de San Lorenzo / German: San-Lorenzo-Hirschmaus / Spanish: Raton ciervo de San Lorenzo

Other common names: San Lorenzo Mouse

Taxonomy. Peromyscus guardia interparietalis Burt, 1932, “ South San Lorenzo Island (latitude 28° 36’ N., longitude 112° 51’ W.), Gulf of California, Mexico.”

Although several morphological studies support specific status of P. interparietalis, recent evidence suggests that it might be a subspecies of P. eremicus. Peromyscus interparietalis is in the eremicus species group. Three subspecies recognized.

Subspecies and Distribution.

P.i.interparietalisBurt,1932—SanLorenzoI,BajaCalifornia,Mexico.

Pi.lorenziBanks,1967—LasAnimasI,BajaCalifornia,Mexico.

P. i. ryckmani Banks, 1967 — SalsipuedesI, Baja California, Mexico.

Descriptive notes. Head-body 86-98 mm, tail 87-117 mm, ear 18 mm, hindfoot 22 mm; weight 20-22 g. The San Lorenzo Deermouse is small to medium-sized, with yellowish brown dorsal pelage and blackish brown tips, producing speckled grayish appearance. Venter is white to yellowish white. Tail is longer than head-body length and bicolored, reddish brown above and whitish below. The San Lorenzo Deermouse is similar in size and color to the La Guarda Deermouse (P. guardia), but its hindfeet and tail are shorter, interparietal bone extends to suture between parietal and squama temporalis, edge of nasal is square (not rounded), zygomatic arch widens toward squama temporalis, interpterygoid fossa is narrower, palatal bone is shorter, and incisive foramina reaches first molar.

Habitat. Xeric scrubland and other island microhabitats along rocky beaches, valleys, and low plains at elevations up to c¢.485 m. Vegetation is typically sparse and dominated by chollas and cardones cacti.

Food and Feeding. San Lorenzo Deermice eat seeds, sprouts,flowers, fruits, and insects.

Breeding. Peak reproductive activity occurs in early spring, usually during March,although it can extend into summer. Gestation averages 32 days, and females generally have four offspring in a litter.

Activity patterns. San Lorenzo Deermice are nocturnal. They construct nests made of sticks, dry leaves, and other materials and dig burrows between large rocks.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Critically Endangered on The IUCN Red List.

Bibliography. Banks (1967), Bourillon et al. (1988), Brand & Ryckman (1968), Burt (1932), Hafner et al. (2001), Hall (1981), Lawlor (1971a, 1971b), Lopez-Forment et al. (1996), Musser & Carleton (2005), Ramirez & Avila (2014a).