Monday, November 06, 2023

FIF 2023 Research Grant to Help Count Island Spotted Skunks

Friends of the Island Fox received a record number of grant applications this year. Funds were awarded to two projects. Today we highlight:

Desirae Thomaier a masters student in Biological Sciences at Cal Poly San Luis Obispo. 


Island foxes share their habitat with island spotted skunks on Santa Cruz and Santa Rosa Islands. When island fox numbers declined due to golden eagles, island spotted skunk numbers increased dramatically. As island fox populations recovered, skunk numbers appeared to decline. 

While some researchers have attempted to follow island spotted skunks with radio-tracking collars, the spotted skunks small size and seasonal weight fluctuations make it difficult to effectively use radio collars. Prior studies recommended wildlife field cameras as a way to potentially quantify the number of island spotted skunks on each island.

Thomaier's project–Occupancy modeling of Island Spotted Skunks on Santa Rosa and Santa Cruz Islands–will deploy 60 field cameras across each island for a full year.

Hopefully, this effort will provide a better accounting of island spotted skunks numbers and how they are "responding to very high fox abundance."

Island spotted skunks are nocturnal. Interactions between island foxes and island spotted skunks under the cover of darkness. Thomaier's cameras may also uncover additional information about the interactions between these two island carnivores.

The series of three photos below were taken over the course of 8 minutes.

One spotted skunk followed less than a minute later by an island fox.

Followed 7 minutes later by two island spotted skunks.

One skunk is in the upper left corner with the second skunk right on its heels. (photos courtesy of Channel Islands National Park)

What is the story here? We really don't know. Hopefully, Thomaier's research project will help provide a more accurate count of island spotted skunk populations and shine a light on the complicated relationship between these two island predators.

Island spotted skunks may deserve separate species status. FIF Research Grant 2022 recipient Julia Owen will be presenting at the California Island Symposium this week in Ventura.