Rodent Diversity and Population Dynamics

How can the blue oak woodlands tucked in the rolling hills and steep canyons of a popular California State Park provide healthy wildlife habitat and an exhilarating setting for off-highway vehicle (OHV) recreation? The California Department of Parks and Recreation seeks to answer this question as it monitors and manages Carnegie State Vehicular Recreation Area to allow for off-highway vehicle recreation alongside conservation and protection of wildlife, including small mammals.

To this end, MIG partnered with California State Parks to conduct a 3-year live trapping, mark-recapture study at Carnegie State Vehicular Recreation Area to compare rodent population abundance and community diversity between blue oak woodland sites with and without OHV areas.

During 7,800 trap nights, MIG biologists live-trapped and ear-tagged over 600 individual rodents representing eight species, including pinyon mouse (Peromyscus truei), desert woodrat (Neotoma lepida), and San Joaquin pocket mouse (Perognathus inornatus). Data analysis included the use of regression modeling and population demographics modeling using Program MARK.

Rodents are model species for understanding the ecological effects of anthropogenic activities, and they are often keystone species that significantly influence biological diversity and biochemical processes. This study is thought to be the first of its kind to examine the effects of OHV recreation on rodent communities and populations in a woodland community.

Results from the study will be integrated into long-term datasets used to further manage OHV use and small mammal populations at the recreation area.