DUSKY-FOOTED WOODRATS (Neotoma fuscipes) at HASTINGS: A RESEARCH TRADITION

                 read an August, 2007 interview with Dr. Matocq about recent findings...

Dusky-footed woodrats have been studied extensively at the Hastings Natural History Reservation starting in the 1940's with the work of Jean Lindsdale and Lloyd Tevis who published their findings in the 1951 book "The Dusky-footed Wood Rat."

Members of the genus Neotoma are found only in North and Central America with California being home to three species, N. cinerea (the bushy-tailed woodrat), N. lepida (the desert woodrat) and our own dusky-footed woodrat, N. fuscipes. Dusky-footed woodrats range in a narrow band from the Columbia River, throughout California and into Northern Baja California (Figure 1) occupying a variety of habitats including chaparral, coastal sage-scrub, and juniper-pinon pine, oak and riparian woodlands. Dusky-footed woodrats are a medium-sized rat with an average nose to rump length of about 7 inches (Figure 2).

Figure 1: The range of dusky-footed woodrats. Numbers refer to the 11 subspecies and groups A, B, and C represent three distinct morphological groups within the species.

Woodrats are most known for the elaborate stick houses that they build and live in (Figure 3). These conical structures can be found high up in the oak trees of Hastings but most commonly they are leaned up against the base of a coast live oak or willow. These complex structures have multiple chambers within them ranging from the actual nest to latrines and even special areas where leaves are stored until the toxic chemicals they contain are leached out allowing consumption. Woodrat houses range in shape and size but it is not uncommon to find ones up to six feet tall. Each house is occupied by a single adult although moms share their houses with their young for their first two months of life. At that point the young move into adjacent houses still near their mother. Eventually, the mother will die and one of her offspring will inherit her house. This allows for a house to be maintained for decades by several generations of the same family

Woodrats are not the only occupants in their houses. They are known to share their houses with a number of other vertebrate and invertebrate species from salamanders to spiders. It has been shown that species diversity is increased with the presence of woodrat houses. The houses provide shelter from temperature and moisture extremes not only for the woodrats but for a multitude of species that may not otherwise be able to endure the local environment.

Ongoing research concerning the woodrats at Hastings is focused on their mating and social systems. Marjorie Matocq, a graduate student in the Museum of Vertebrate Zoology, is combining field work with DNA analysis to determine how local population dynamics influence the generation and maintenance of genetic diversity in this species. When you are exploring Hastings or other areas of California remember to look for woodrat houses and be reminded of the industrious and clever animals that built those structures and the many generations of a single family that have maintained that important resource.

Here, a woodrat is running down a fallen log, carrying leaves of the live oak (Quercus agrifolia). Incredibly, the woodrat can survivie on a diet of such leaves. They often move on fallen logs so they are not heard by owls; moving around on the leaves on the forest floor is noisy and allows owls and other predators to find them. Woodrats are important diet items of owls, including the rare Spotted Owl.

Further Reaading:

Linsdale, J. M. and L. P. Tevis. 1951. The Dusky-footed Wood Rat. A record of observations made on the Hastings Natural History Reservation. Univ. Calif. Press, Berkeley. 664 p.

Linsdale, J. M. and L. P. Tevis. 1956. A five-year change in an assemblage of wood rat houses. J. Mammal. 37:371-374.

Caldwell, G. S., S. E. Glickman, and E. R. Smith. 1984. Seasonal aggression independent of seasonal testosterone in wood rats. Proc. Natl. Acad. Sci. 81:5255-5257.

Marks, Judie. 1999. Woodrats Know How to Build and Pack it Away. Monterey County Herald April 2 , D-1.