Assessing genomic consequences of invasive black rat colonization and eradication on an endemic insular rodent

Cody Edwards, Associate Professor, Biology; Associate Provost,received funding for the study: "Assessing genomic consequences of invasive black rat colonization and eradication on an endemic insular rodent." 

Edwards has four objectives for this research. 

First, he aims to quantify functional and neutral genetic diversity of Channel Island deer mice (Peromyscus maniculatus subspp.) on Anacapa Island, San Miguel Island, and Santa Rosa Island at time points from 1892 to 2004. 

Second, he intends to evaluate whether the 2004 Anacapa Island P. maniculatus population, collected after the Channel Islands National Park Services eradicated the black rat (Rattus rattus) on the island, is less genetically diverse compared to historic levels pre-eradication (1940, 1978). 

Third, he aims to evaluate whether the 1939 San Miguel Island P. maniculatus population, collected after the 1900s introduction of the black rat, is less genetically diverse compared with pre-introduction levels (1892). 

Finally, he hopes to determine whether rat eradication with a native rodent present is a viable conservation strategy by comparing genomic consequences of eradication on Anacapa Island, colonization on San Miguel Island, and baseline P. maniculatus diversity levels on Santa Rosa Island, which has no historical or current black rat presence, as a control group. 

 Edwards received $2,450 from the American Wildlife Conservation Foundation for this project. Funding began in March 2022 and will end in late July 2023.