Virtual Program: How Microbes Influence Island Fox Health and Understanding Island Spotted Skunks

 Join Friends of the Island Fox for a virtual

"Date with a Fox"

Tuesday, January 31 at 6:30–7:30 pm (Pacific Time)

on Zoom

Hear directly from researchers investigating island fox health and biologists working in the field on the Channel Islands.

Jasmine Lu became acquainted with Channel Island foxes while working on her senior thesis at Princeton under the guidance of Alexandra DeCandia, Ph.D. Their work investigated how mite infection can destabilize the microbial community structure in the ear canals of Santa Catalina Island foxes. Their findings have recently been published in the journal Molecular Ecology. Lu will explain their discoveries; she says "It's exciting to be able to contribute to the growing body of knowledge on this fox population!"

 

 

Lara Brenner is a FIF Board Member, island biologist for the Nature Conservancy, and member of the Island Spotted Skunk Conservation Working Group. Island spotted skunks co-exist with island foxes on Santa Cruz and Santa Rosa Islands, but little is known about these tiny predators. As island foxes have recovered, how have island spotted skunks been affected? What are we learning about the relationship between these two endemic predators and what more needs to be investigated? Brenner will provide an update on island spotted skunks.

It should be a fascinating evening. We hope you will join us for this free virtual event. Reservations are required.

Watch The Recorded Program

More on FIF and island spotted skunks

Videos of past "Date with a Fox" programs are available here.

FIF Research Grant Will Investigate Island Spotted Skunk Genome

Meet Julia Owen, a researcher at the University of California, Davis Mammalian Ecology and Conservation Unit. 

FIF's 2022 Research Grant will help process samples in Owen's effort to decode the genome of island spotted skunks and determine their genetic history. When did this island endemic diverge from a mainland ancestor and which mainland spotted skunk is their closest ancestor?

 

Little is known of the island spotted skunk that shares habitat with island foxes on two islands–Santa Rosa and Santa Cruz. Because island spotted skunks are nocturnal and reclusive, basic knowledge like diet, social behavior, and even when these tiny predators reproduce remains unclear. Yet, island foxes and island spotted skunks have an impact on each other. More on foxes and skunks sharing habitat

 

Currently island spotted skunks (Spilogale gracilis amphiala) are considered a subspecies of western spotted skunks. Physically they all appear similar to human eyes and, until recently, the relationship between spotted skunks across North America has been regarded as primarily a division of western and eastern species. New genetic research, however, is revealing that there are substantial genetic differences and even reproductive variation between the two groups–western spotted skunks have delayed implantation of embryos and eastern spotted skunks do not. "Delayed implantation" means that spotted skunks in difficult desert, mountain, or isolated environments can breed at a time that is easier to find a mate, but the embryo within the female will stop development for a period of time and then resume development so that birth will occur at a more optimal time for success.

"Through the use of genetic and genomic tools, " Owen explains, "it is now becoming clear that island foxes and island spotted skunks have been coinhabitants of Santa Cruz and Santa Rosa Islands for thousands of years. Investigating the evolutionary history of island spotted skunks will also provide information on the evolutionary ecology of island foxes on the northern Channel Islands."

This work could also help us understand if island spotted skunks should be considered a unique island species, like island foxes. Julia Owen adds, "shedding light on the distinctness of each population of island spotted skunks may help inform and increase conservation efforts on each island."

Friends of the Island Fox participates in the Island Spotted Skunk Conservation Working Group. For more about island spotted skunks check out their website: www.islandspottedskunk.com

See Ellie Bolas talk on preliminary research on island fox and island spotted skunk interactions

Island Foxes and Island Spotted Skunks

On two of the Channel Islands, island foxes share their ecosystem with island spotted skunks.

The island spotted skunk is smaller than the island fox, and even more elusive. Because the skunk is primarily nocturnal, few people encounter them and, until recently, little was known about them.

When the island fox faced near-extinction on Santa Rosa and Santa Cruz Islands in 2000, people took note of the island spotted skunk for the first time. The first counting of island spotted skunks occurred when they were captured during island fox counting.

When the island fox population was low, the population of island spotted skunks soared. This gathering of spotted-skunk and island-fox cake pops, illustrates the overwhelming number of spotted skunks to island foxes. 

By 2014, however, the foxes were overtaking the skunks in reproduction and survival; island fox numbers almost equaled the estimated number of spotted skunks. As island foxes continued to increase across Santa Rosa and Santa Cruz Islands, the island spotted skunk population continued to decline dramatically. (Or at least, the number of island spotted skunks captured during island fox counting has declined.)

The gathering of cake pops–compiled by researchers Juliann Schamel and Angela Guglielmino–demonstrates how drastic the population shift has become.

What we don't know is: Why? Why have island spotted skunk numbers declined so much? What is the normal population relationship between these two species? Are island foxes out-competing island spotted skunks or is something else at play?

In the past few years, researchers have begun looking into the life and behavior of the island spotted skunk. FIF contributed support to researcher Ellie Boas to supply batteries for the first trap cameras that were put out to capture images of island spotted skunks. Researchers continue to try to capture images of island foxes and spotted skunks interacting, but it has been a challenge.

2020 opened with an important meeting of biologists, wildlife veterinarians, researchers, and invested organizations and institutions to pursue inquiry into the island spotted skunk. Following the example of the Island Fox Conservation Working Group and the successful conservation efforts for the island fox, the group will work to solve questions and develop action plans.

Friends of the Island Fox sends a resounding "Yip, Yip" to the newly formed Island Spotted Skunk Conservation Working Group. 

May we all work together to understand the important relationship between these two unique island species.

Fox Foto Friday - Foxes and Spotted Skunks

How can we enter the world of the island fox and the other animals that live on the Channel Islands without disturbing their natural behavior? One way is with strategically placed movement-activated cameras.

Researchers found an area with evidence of island fox activity. Evidence like tracks and scat. They positioned the special camera and left it to document the animals that walked past. Not only was an island fox using this area of Santa Rosa Island, so were the two spotted skunks, pictured below. Both were using the area at night.

Notice that the dates on the two images are months apart. Still, images like these are helping to provide information to better understand the interactions between species and the species themselves. Island spotted skunks are considered solitary creatures, yet the image captured two together. The biologists titled this image a "rumble." What brought these two skunks together? Territorial dispute? Mating season? There is so much to learn about the lives of island foxes and their neighbors.