Ecology of muskrats (Ondatra zibethicus) on the Fall River

Predation of songbird nests in California riparian areas

Poor nesting success of songbirds in the Cosumnes River Preserve prompted this study to determine if nest predation was a factor.  Preliminary results from an analysis of predation on artificial nests has indicated that roof rats (Rattus rattus) are significant predators of songbird eggs.  We have now expanded this research to other riparian areas in California including Bobelaine Sanctuary (north of Sacramento on the Feather River) and Kern River Preserve, Southern California.  Although roof rats are well-known for their negative impacts on natural systems, there have been few attempts to document the impacts of these animals on natural systems in the continental USA.

Click here to see predators and visitors to artificial nests as photographed by remote cameras.

Results, 2001

Principal Investigator: Desley Whisson Project Duration: June 1995 - December 1996 Funding source(s): Renewable Resources Extension Act and California Department of Food and Agriculture

This project was undertaken to determine if bait stations containing rodenticides for ground squirrels could be modified to exclude endangered kangaroo rats. Several modifications to existing bait station designs were tested for accessibility by ground squirrels and kangaroo rats. Laboratory and field studies identified two designs that excluded kangaroo rats, while allowing access by California ground squirrels. The modifications are simple to make and inexpensive, thereby providing an easy solution for farmers and ranchers to control ground squirrels while conserving endangered kangaroo rats. See "control of ground squirrels in agriculture" for specifications.