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Posts Tagged: fox

Take action to help improve red fox conservation efforts

Sacramento Valley red fox. (Photo: Ben Sacks)
The red fox (Vulpes vulpes) is one of the most widely distributed terrestrial mammals in the world. California is home to red foxes of both native and non-native ancestry. Red foxes in the Sacramento Valley were long thought to be non-native. However, in 2005 genetic analyses performed in the UC Davis School of Veterinary Medicine’s, Veterinary Genetics Laboratory revealed these foxes to be native to the region and potentially in decline.

The estimated population size of Sacramento Valley (SV) red foxes is very small, indicating possible conservation concerns. In addition, SV red foxes occur in a highly modified landscape used for intensive agriculture. In particular, while preliminary analyses indicate that the current distribution of SV red foxes in the northern part of the Central Valley overlaps a floodplain once characterized by native grasslands and riparian forests, these habitats have been heavily modified to meet agricultural needs. The continuous modification of habitats for agriculture in the SV may be impeding on the limited habitats available to foxes, particularly since these foxes only live at low elevations.

Based on their unique natural history and their close proximity and dependency on human modified landscapes, SV red foxes face multiple threats. Direct threats include deaths attributed to a variety of causes: residents protecting their poultry, vehicle collisions, exposure to pathogens from domestic animals, and ingestion of poison bait meant for rodent control or eating rodents killed by poison. Additional threats for the viability of SV red foxes are the species’ limited range and distribution. Species isolated in a single region with a small population, like the SV red fox, experience minimal genetic variation in their gene flow, and could potentially face genetic introgression from adjacent non-native populations. These threats, which are likely increasing over time, may warrant placing the SV red fox on the threatened species list in the near future.

In 2007, an online reporting system was launched by the University of California, Davis, with goals of involving the public in documenting any potential fox sightings. The goal of this website was to involve the local community with locating SV red foxes so that samples could be obtained for genetic testing and surveillance could be set up for behavior monitoring.

Now, master's student Amy Brasch of Victoria University of Wellington is assessing how effective public input was on locating the foxes and how the website can be improved for future conservation efforts.

You are invited to share your opinions regarding red foxes and the fox sighting website in a 5-minute survey located on the fox sighting website:

The results of this survey will enhance the website as well as develop a better understanding of how effective public input is on locating Sacramento Valley red foxes.

Sacramento Valley fox pup. (Photo: Mark Statham)
Sacramento Valley fox pup. (Photo: Mark Statham)

Posted on Friday, October 19, 2012 at 8:27 AM

Vertebrate Visitor

I enjoy watching the wildlife in our suburban garden, so when a squirrel appeared at our bird feeder, I was very excited. We have lived in our house for more than fifteen years and this is only the second time we have seen squirrels in our garden. The first sighting was not long after we moved in, so I think the current visits may be due to our recent addition of the bird feeder.

The bird feeder is an easy reach from the fence for this hungry tree squirrel. (Photo by Sharon Leos)

I checked the UC Integrated Pest Management website and found the squirrel in my photo is probably an eastern fox squirrel (Sciurus niger), a type of tree squirrel. Tree squirrels are active during the day all year-round (they do not hibernate) and enjoy eating a variety of items, several of which are found in the garden. So far, the squirrels in our yard have only eaten bird seeds, so I don’t mind them visiting - emphasis on visiting. I do not want a squirrel population explosion, like we seemed to have had with rats this summer, but that is a story for another day.

Keeping squirrels out of a garden or away from bird feeders can be challenging because they are very smart creatures. I will move to the birdfeeder farther from the fence, hopefully out of squirrels’ reach. The squirrels in our backyard do not like the presence of dogs, so our dogs will be outdoors more in the coming days where I know they will enjoy more time under the Solano sun.

For more information on managing tree squirrels in the garden visit the UC IPM website:

Posted on Thursday, September 8, 2011 at 8:02 AM

Sierra Nevada red fox spotted on Sonora Pass

UC Davis researchers' recent confirmation that Sierra Nevada red fox is still roaming the forest 200 miles further south than thought could ignite a political battle about endangered species, according to an article by Michael Doyle of McClatchy News Service.

The story appeared in the Sunday Fresno Bee, but online was only available on the Miami Herald website.

California law currently protects the fox, but the federal Endangered Species Act does not. According to the McClatchy story, it is a long, politically charged process to add an animal to the federal list, and the local congressman, George Radanovich, is unlikely to support such a move.

"Our state water supply has been hijacked by the radically irresponsible Endangered Species Act," Radanovich said in a House speech last year, according to the story.

A Sept. 2 UC Davis news release about the red fox find has captivated the media. The release, picked up by dozens of news outlets and blogs, said DNA analysis of saliva from the tooth punctures on a bait bag allowed UC Davis wildlife genetics researchers Ben Sacks and Mark Statham to determine for certain that the animal is a Sierra Nevada red fox.

"It's got a genetic signature that we haven't seen outside of the skulls and skins of museum specimens collected before 1926," Sacks was quoted in the Los Angeles Times. "So we now have two small, isolated populations, and we don't know how big the second group is. That's about as endangered as you can get."

Federal biologists, UC Davis genetics researchers and university students began setting up additional monitoring stations and cameras to try to determine the size and health of the Sonora Pass population.

"It is very unusual to discover a new large animal species," a Forest Service spokeswoman told the Times. "In this case, it was like finding a rare jewel in a totally unexpected place."

UC Davis wildlife genetics researcher Ben Sacks holds a native Sacramento Valley red fox.
UC Davis wildlife genetics researcher Ben Sacks holds a native Sacramento Valley red fox.

Posted on Monday, September 13, 2010 at 6:29 AM

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