CONSERVATION - WILDLIFE PROGRAMS
Catalina Island Shrew
Background
The Santa Catalina Island Ornate shrew (Sorex ornatus willetti) is the rarest, endemic mammal on Catalina Island. Despite extensive trapping efforts, only 40 shrews have been documented since their discovery in 1941. Due to their secretive nature, much of our knowledge of this shrew is gleaned from mainland subspecies which are easier to detect.
Jack Baldelli
Catalina Island Shrew
Why Do We Care?
Since the shrew’s discovery, Catalina Island has been through extensive droughts (2012-2016) and drastic habitat change following the removal of feral pigs and goats. The effects of these environmental changes on shrew distribution and survival are still unknown. The short lifespan of 12 to 16 months (Owen and Hoffmann 1983) means that prolonged drought could have a large effect on their population size. Due to the scarcity of these individuals, and the lack of information about their natural history, the Catalina Island shrew was listed as a Species of Special Concern in 1996 by the California Department of Fish and Wildlife.
Jack Baldelli
What Do We Do?
Since 2018, Conservancy biologists have been monitoring the shrew population with remote camera traps. This method has proved effective for the mainland Buena Vista Lake Shrew; however, the cameras only detected 2 Catalina Island Shrews from 2018 to 2022. Historically, pit-fall trapping proved an effective method for finding and monitoring shrews on Catalina; therefore, Conservancy biologists are implementing a new pit-fall trapping study in 2023. In addition, Conservancy biologists are considering other detection and management methods such as eDNA, genetic sequencing and habitat restoration.