Island foxes may need genetic rescue

Date:March 21, 2016

Source:Colorado State University

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 inMolecular 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.

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