Stanislaus River Report

Riparian Woodrat

Life History

This species is common in deciduous valley oak habitats and tends to be most numerous where shrub cover is dense and not found in open areas. Because its historic range is the same as that of the riparian brush rabbit, habitat restoration for one will benefit the other as well.

Houses of sticks and other litter are common where woodrats are found. The houses of riparian woodrat tend to be constructed on the ground against or straddling a log or exposed roots of a standing tree. They may also be in the crotches of trees, hollow logs, and tree cavities.

This species tends to be mostly nocturnal and feeds primarily on plant material (Ingles 1965). Food items include leaves, flowers, nuts, and berries, and forages off the forest floor (Jameson 1988).

Breeding occurs throughout most of the year except for late autumn and early winter. The gestation period is somewhere between 23 and 38 days with females usually having more than one litter per year. Litters vary in size from one to three young, with two being the most common litter size.

Predators to the riparian woodrat are owls, foxes, coyotes, large snakes, and feral cats and dogs.

Findings and Conclusions

Any project involving the Stanislaus River needs to consider potential impacts to the riparian forest occurring at, or adjacent to, Caswell Memorial State Park and consequently impacts to the riparian woodrat.