Showing posts with label Urocyon littoralis. Show all posts

Tuesday, March 22, 2016

Channel Island foxes may need genetic rescue

IMG_2874 Santa Cruz Island Fox, Channel Islands National Park

Date:: March 21, 2016
Source:: Colorado State University
Summary:: The island fox has made a remarkable comeback from the brink of extinction, with three of six populations on their way to becoming the fastest mammal recovered under the Endangered Species Act. But new research uncovers a hidden danger to the future viability of some island fox populations.

The island fox has made a remarkable comeback from the brink of extinction, with three of six populations on their way to becoming the fastest mammal recovered under the Endangered Species Act. But new research published online March 17 in Molecular Ecology uncovers a hidden danger to the future viability of some island fox populations.

Chris Funk, associate professor in the College of Natural Sciences' Department of Biology, led the research team that conducted the largest and most in-depth genetic study to date of California Channel Island foxes. Funk is also director of the SoGES (School of Global Environmental Sustainability) Global Biodiversity Center at CSU. The study confirmed that each island's fox population likely warrants designation as a unique subspecies. But it also found that one subspecies, on San Nicolas Island, may require genetic rescue to reduce its risk of extinction.

The San Nicolas Island fox has the lowest genetic variation ever found in a mammal species, making them especially vulnerable. "Low genetic diversity may lead to lower survival and reproductive success, and may reduce the ability of a population to adapt to climate change or new, introduced diseases," Funk said. "With a dwindling population of fewer than 300 adults, actions need to be taken quickly to preserve this important member of the Channel Islands ecosystem."

The scientists say that if this subspecies' genetic health is poor, it may be necessary to use "genetic rescue," bringing island fox individuals from other islands to boost the San Nicolas gene pool. This approach has been successfully implemented in the past to save populations from extinction, including the resuscitation of the Florida panther back in 1995.

The island fox is the smallest fox species in the U.S and found on six of the eight California Channel Islands. Four of the six fox subspecies (not including the San Nicolas population) were listed as endangered under the U.S. Endangered Species Act in 2004 due to precipitous population declines caused by predation by golden eagles and an epidemic of canine distemper virus. Since then, concerted efforts by various island managers enabled island fox numbers to recover sufficiently that the U.S. Fish & Wildlife Service plans to remove or move them down the list.

"The recent island fox recovery was the result of an impressive collaboration of scientists and land managers. It may now be time to examine whether unconventional methods like genetic rescue are needed for the San Nicolas Island fox," said Scott Morrison, The Nature Conservancy's director of science and a coauthor of the study.

If managers decide that genetic rescue is necessary to maintain robust populations of island foxes, this study can be used to inform which island fox subspecies would be the best source population.
Robert Lovich, a U.S. Navy biologist in California and a coauthor of the study, said: "Long-term monitoring of the island fox and new genomic technologies now give us the capacity for proactive management with far greater precision and a better expected outcome for island foxes in general."

Story Source:
The above post is reprinted from materials provided by Colorado State University. Note: Materials may be edited for content and length.

Journal Reference:

W. Chris Funk, Robert E. Lovich, Paul A. Hohenlohe, Courtney A. Hofman, Scott A. Morrison, T. Scott Sillett, Cameron K. Ghalambor, Jesus E. Maldonado, Torben C. Rick, Mitch D. Day, Nicholas R. Polato, Sarah W. Fitzpatrick, Timothy J. Coonan, Kevin R. Crooks, Adam Dillon, David K. Garcelon, Julie L. King, Christina L. Boser, Nicholas Gould, William F. Andelt. Adaptive divergence despite strong genetic drift: genomic analysis of the evolutionary mechanisms causing genetic differentiation in the island fox (Urocyon littoralis). Molecular Ecology, 2016; DOI: 10.1111/mec.13605

Colorado State University. "Island foxes may need genetic rescue." ScienceDaily. ScienceDaily, 21 March 2016. <www.sciencedaily.com/releases/2016/03/160321110458.htm>.

Santa Cruz Island Fox, Channel Islands National Park by I-Ting Chiang

Thursday, March 5, 2015

Want to keep these adorable foxes around? Lock up your garbage

By Jason Goldman March 04 2015

Image:Catalina Island Conservancy

Here's something kind of twisted: you know a conservation effort has been successful when the animals you've worked so hard to conserve are numerous enough to be run over by cars. That's what happening now for the island fox, Urocyon littoralis.

The smallest fox in North America, this adorable critter is native to six of the eight Channel Islands, a small archipelago lying just off the coast of California. Back in 1999, the sub-species found on Catalina, the only island with any significant, permanent human presence, plummeted from around 1,300 individuals to just 100 following an outbreak of canine distemper virus (CDV). It's thought that the virus made its way to the island not via domestic dogs, the obvious culprits, but thanks to a stowaway raccoon. For several years, researchers working with the Catalina Island Conservancy instituted a captive breeding program to rescue the island's foxes from the brink of extinction. Thanks to that effort, along with CDV vaccines and an intensive monitoring program, the island is once again home to some 1,700 foxes.

But more foxes means more chances for negative encounters with humans. In 2014, at least 25 foxes died from human-related causes: 21 of them died because of vehicle collisions (though biologists think that number may be higher), two drowned in uncovered water containers, one was killed by an unleashed domestic dog and the last one died because it ingested rat poison.

A significant number of the dead foxes were found near trash cans – and that's no surprise since food waste is an attractive source of nutrition for wildlife. That's why the Catalina Island Conservancy has announced a new effort to distribute fox-proof trash cans throughout the 88 percent of the island it manages. The conservancy is planning on installing 150 new trash cans throughout its land as well as in key spots in Avalon, the main town on the island, at a price tag of $2,000 apiece.

Image: Catalina Island Conservancy

"While we cannot document all fox deaths, we can see that the inadequate handling or containment of trash has become a serious threat to foxes and other wildlife," said Julie King, the conservancy’s director of conservation and wildlife management in an official statement. "Installing animal-proof trash and recycling receptacles will prevent the foxes and other wildlife from entering the containers and help eliminate trash spills that attract the foxes and other wildlife into inhabited areas and roadsides, where they may be struck by a vehicle."

The team isn't attempting to protect the foxes just because they're darn adorable, but that helps. Because they are cute and charismatic, people may be more motivated to help protect their habitat. In doing so, all of the other island species wlll indirectly benefit. More importantly, their conservation is vital because the fox is thought to be a keystone species. Small as they may be, the foxes are actually the islands' largest native land predator, rivalled only by raptors like bald and golden eagles. And because they're willing to eat just about anything, they play an important role in maintaining a sort of 'balance' in the island's plant and animal communities. Without these tiny predators, smaller mammals like mice could overpopulate the island, and many of the native trees and plants could have trouble spreading their seeds, which remain in the foxes' droppings after they've eaten their fruit. The foxes' ability to thrive allows the rest of the island's inhabitants to thrive as well.