endemic to a single state or province

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (250-20,000 square km (about 100-8000 square miles)) Lower San Joaquin Valley, California (Williams and Kilburn 1984); known historical distribution included areas along the San Joaquin, Stanislaus, and Tuolumne rivers, and Corral Hollow, in San Joaquin, Stanislaus, and Merced counties; presently known to be extant only at Caswell Memorial State Park (Williams 1993). Status of a population that existed in the early 1970s near the type locality at Vernalis is unknown (USFWS 2000).

Historic Range:
U.S.A. (CA)

Comments: Wooded riparian areas.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 1 - 5

Comments: One known occurrence.

1 - 1000 individuals

Comments: Williams (1993) estimated the population of the single known occurrence at 437 individuals. At least a small population survived flooding in January 1997 (15 individuals were live-trapped between April 1997 and March 1998, USFWS 2000).

United States

Rounded National Status Rank: N1 - Critically Imperiled

Rounded Global Status Rank: T1 - Critically Imperiled

Reasons: Occurs in one location in riparian habitat in the San Joaquin Valley, California; total population in the early 1990s was estimated at about 450; habitat has shrunk greatly and is now very limited; vulnerable to factors affecting small populations.

Current Listing Status Summary

Status: Endangered
Date Listed: 02/23/2000
Lead Region:   California/Nevada Region (Region 8) 
Where Listed:


Population detail:

Population location: entire
Listing status: E

For most current information and documents related to the conservation status and management of Neotoma fuscipes riparia , see its USFWS Species Profile

Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species

Comments: Highly vulnerable to habitat alterations such as those resulting from fire, drought, and livestock grazing. Most of historic habitat and flood refugia have been converted to cultivated fields, orchards, and vineyards (Williams and Basey 1986); clearing of vegetation for levee maintenance also has diminished habitat. Severe flooding could eliminate the population at Caswell Memorial State Park; no suitable refugia exist outside the park; a small population survived extensive flooding in January 1997. Vulnerable to all factors that affect small populations. Could be detrimentally affect by rodent control that occurs within and outside the park.

Management Requirements: See "Draft recovery plan for upland species of the San Joaquin Valley, California," available in September 1997 (U.S. Fish and Wildlife Service, Sacramento, California; 916-979-2725).

Needs: Protect the population in Caswell Memorial State Park. Promote riparian habitat restoration in the San Joaquin Valley.