Fox spit helped Forest Service confirm rare find

September 3, 2010
UC Davis wildlife genetics researcher Ben Sacks holds a native Sacramento Valley red fox (Vulpes vulpes patwin). (UC Davis photo)

( -- Three weeks ago, when U.S. Forest Service biologists thought they had found a supposedly extinct fox in the mountains of central California, they turned to UC Davis for confirmation.

Photographs taken by a Forest Service trail camera in Sonora Pass seemed to show a red fox (Vulpes vulpes necator) biting a bait bag of chicken scraps. That would be an amazing discovery, since no sighting of that species has been verified south of Mount Lassen, 200 miles away, since the mid-1990s.

The biologists shipped the bait bag to wildlife genetics researchers Ben Sacks and Mark Statham at the UC Davis Veterinary Genetics Laboratory. Since 2006, they have radically altered our understanding of red foxes in California, supplying information crucial to conservation efforts.

Sacks and Statham scraped saliva from the tooth punctures on the bag and analyzed the DNA within. Before you could say spit, they had the answer: definitely a Sierra Nevada red fox.

“This is the most exciting animal discovery we have had in California since the wolverine in the Sierra two years ago -- only this time, the unexpected critter turned out to be home-grown, which is truly big news,” Sacks said. (The wolverine was an immigrant from Wyoming).

Four years ago, Sacks began analyzing California red fox DNA collected from scat, hair and saliva from live animals, and skin and bones from museum specimens. Until then, the expert consensus was that any red fox in the Central Valley and coastal regions of the state was a descendant of Eastern red foxes (V.v. fulva) brought here in the 1860's for hunting and fur farms.

Sacks and his colleagues have confirmed that red fox populations in coastal lowlands, the San Joaquin Valley and Southern California were indeed introduced from the eastern United States (and Alaska). But they have also shown that:

• There are native California red foxes still living in the Sierra Nevada.

• The native red foxes in the Sacramento Valley (V.v. patwin) are a subspecies genetically distinct from those in the Sierra.

• The two native California subspecies, along with Rocky Mountain and Cascade red foxes (V.v. macroura and V. v. cascadensis), formed a single large western population until the end of the last ice age, when the three mountain subspecies followed receding glaciers up to mountaintops, leaving the Sacramento Valley red fox isolated at low elevation.

Sacks' extensive research program focuses on canids, especially red foxes (evolution, ecology and conservation) and dogs (genetics, geographic origins and spread). He and his students also are working on other carnivores, including disease ecology and interactions among fishers, bobcats, coyotes and gray foxes, and population genetics of ringtails and coyotes.

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1 / 5 (3) Sep 03, 2010
awe... look at the sedated fox in the man's arms --- if it was awake it would have knawed off the guys face by know -- and who knows what taking a fox that WE THOUGHT WAS EXTINCT from its home will do-- will it breed now having been molested by humans??? sheash - give me a break charlie brown did no one say - hey it might be an extinct fox, lets tranqualize it get a sample and leave it the heck alone in case we further destroy them if we are right.

There is a reason people/scientists should take an ethics arguement class in college.
5 / 5 (2) Sep 03, 2010
To El_Nose:
If you'll notice, the fox in the picture is of the species V. v. patwin, not V. v. necator.
Additionally, necator was not thought to be extinct (it is listed as a threatened species though). The article is making mention of the location in which the fox was observed. The species was identified using DNA from a bite bag, not from collecting samples in person.

There is a reason people should take reading comprehension classes in college.
not rated yet Sep 04, 2010
"There is a reason people should take reading comprehension classes in college."


This is so true for too many people.
People just skim things at best; is this Twitter-style reading comprehension now?

Great to see native animals still surviving out there!!

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