Thursday, April 26 , 2018, 1:16 am | Fair 51º

 
 
 
 

Island Fox Recovery Growing Where It Counts

Channel Islands biologists log a rapid rise in fox population, thanks to a captive breeding program and the removal of golden eagles from the archipelago

On a recent three-day trip to Santa Cruz Island, I encountered at least a dozen island foxes across the southeast end of the island. Three at the beach at Scorpion Anchorage foraged in the cobblestones. Three more ran amok in the upper campground in Scorpion Canyon. Two were high on Montana Ridge frolicking through a stand of blue dicks. Several more scoured the dry creekbed at Smugglers Cove. This was more than I’d seen on one trip since the early 1990s.

An island fox surveys the landscape from the sidelines at Scorpion Ranch on Santa Cruz Island.
An island fox surveys the landscape from the sidelines at Scorpion Ranch on Santa Cruz Island. (Chuck Graham photo)

Captive breeding of the endangered island fox helped stabilize their numbers across the rugged archipelago, with the last captive fox released on Santa Rosa Island. Since then their numbers have soared, more than doubling on Santa Cruz and San Miguel islands. In November, Channel Islands National Park and The Nature Conservancy felt confident enough to shut down captive breeding, but they didn’t envision this swift of a recovery.

“Their numbers are totally skyrocketing,” said Tim Coonan, a National Park Service terrestrial biologist. “Remove a primary mortality threat and you’ll have a fairly robust recovery.”

Coonan was referring to golden eagles that colonized the islands in the 1990s, decimating island fox populations across the chain. Initially lured to the national park by a healthy feral pig population on Santa Cruz, the non-native raptors soon realized the foxes were an easier kill on the three northern islands. The tiny house cat-sized predators have always been at the top of the food chain — until the golden eagles arrived.  Around 45 of the predatory raptors were trapped, fitted with a GPS and relocated to northeastern California.

Coonan said island fox numbers on Santa Cruz Island are around 740, but that doesn’t include juveniles and pups, and he believes it’s more like 1,000 animals. That’s up from around 350 foxes from last year. Populations are also high on windswept San Miguel Island, with 280 island fox adults and pups combined.

“The island fox is approaching biological recovery pretty quickly,” Coonan continued. “We’re pretty much where we want to be at an 80 to 90 percent survival rate. A little eagle removal went a long way.”

Current numbers are based on grid trappings. Grids are 1,500 feet by 4,000 feet in size. About 18 traps are inside each grid, 250 meters apart.

Coonan said there are approximately 120 island foxes on Santa Rosa Island, but it was not an entirely accurate number because biologists used transect trappings. That involves trapping in a straight line on old cattle ranching roads and trails, which is sufficient for catching and radio collaring foxes. Reproduction on Santa Rosa has been slow in island fox populations, but their numbers are rising gradually.

Taking its first tentative steps toward freedom, and island fox checks out its new home on Santa Cruz Island.e
Taking its first tentative steps toward freedom, and island fox checks out its new home on Santa Cruz Island. (Chuck Graham photo)

“Santa Rosa is still slow,” he said. “We don’t have a good idea how many island foxes are on Santa Rosa, so we’ll be trapping in grids this summer.”

I asked Coonan if there will ever come a time when the unique ecosystem on the Channel Islands won’t be able to absorb the growing number of island foxes.

“Island foxes are able to self-regulate a carrying capacity,” Coonan explained. “They’ll stop having pups and slow down.”

— Local freelance writer Chuck Graham is editor of Deep magazine.

  • Ask
  • Vote
  • Investigate
  • Answer

Noozhawk Asks: What’s Your Question?

Welcome to Noozhawk Asks, a new feature in which you ask the questions, you help decide what Noozhawk investigates, and you work with us to find the answers.

Here’s how it works: You share your questions with us in the nearby box. In some cases, we may work with you to find the answers. In others, we may ask you to vote on your top choices to help us narrow the scope. And we’ll be regularly asking you for your feedback on a specific issue or topic.

We also expect to work together with the reader who asked the winning questions to find the answer together. Noozhawk’s objective is to come at questions from a place of curiosity and openness, and we believe a transparent collaboration is the key to achieve it.

The results of our investigation will be published here in this Noozhawk Asks section. Once or twice a month, we plan to do a review of what was asked and answered.

Thanks for asking!

Click Here to Get Started >

Support Noozhawk Today

You are an important ally in our mission to deliver clear, objective, high-quality professional news reporting for Santa Barbara, Goleta and the rest of Santa Barbara County. Join the Hawks Club today to help keep Noozhawk soaring.

We offer four membership levels: $5 a month, $10 a month, $25 a month or $1 a week. Payments can be made through PayPal below, or click here for information on recurring credit-card payments.

Thank you for your vital support.


Maestro, Mastercard, Visa, American Express, Discover, Debit

Reader Comments

Noozhawk is no longer accepting reader comments on our articles. Click here for the announcement. Readers are instead invited to submit letters to the editor by emailing them to [email protected]. Please provide your full name and community, as well as contact information for verification purposes only.

Daily Noozhawk

Subscribe to Noozhawk's A.M. Report, our free e-Bulletin sent out every day at 4:15 a.m. with Noozhawk's top stories, hand-picked by the editors.

Sign Up Now >

Meet Your Realtor Sponsored by Village Properties

Photo of Gary Welterlen and Carla Reeves
Gary Welterlen and Carla Reeves
"We both love this business. We strive to make life long relationships from each real estate transaction."

Full Profile >