- Posted By: Susie Kocher
- Written by: Lauren Sommer, KQED News December 14, 2011
Pacific fishers aren't well-known in California. "They're very elusive," says Rick Sweitzer, a fisher researcher at UC Berkeley. "Most people have never seen a fisher because they spend most of their time in the trees." The dark-brown mammals are closely related to weasels.
Fishers once ranged throughout the Sierra Nevada, but their numbers have declined dramatically. Trappers caught them for their fur until it was outlawed in 1946. Clear-cutting drastically reduced the old-growth forests they favor. Now, fishers exist in two isolated populations in the northern and southern Sierras. Sweitzer studies the population south of Yosemite.
Since fishers aren't easy to find, Sweitzer documents them with 500 motion-activated cameras. He attracts them by hanging a meat-filled sock from a tree. "It takes them a little bit of time to chew the sock apart to get at the meat, so we get a lot of photographs."
Sweitzer goes through 2,000 socks a year, so he decided to get the public involved. He's asking for donations of gently-used socks.
"My real motivation for this sock drive is so that I don't have to stand in line at Walmart with two or three cartloads full of all the socks I can find. I get a lot of stares and a lot of interesting questions."
The US Fish and Wildlife Service is currently considering whether the Pacific fisher will be listed under the Endangered Species Act, in response to a lawsuit filed by environmental groups. A group of fishers was released earlier this year near Chico in the hope that the animal will return to its historic range.
If you have socks to spare, you can mail them to the Sierra Nevada Adaptive Management Project at this address:
40799 Elliott Drive
Oakhurst, CA 93644
- Author: Anne Lombardo
Here is a link to recent paper by W. Zielinski and others exploring valuable fisher habit with the use of detailed forest plot inventory data in the northwestern California.
http://www.sciencedirect.com/science/article/pii/S0378112712001417
- Author: Anne Lombardo
- Posted By: Anne Lombardo
- Written by: Rick Sweitzer and Anne Lombardo
Mowgli and Orphan Annie as young kits
Great News!! The Fisher Science Team of the Sierra Nevada Adaptive Management Project have managed to recapture little “Orphan Annie” (aka F39) for the first time since her release nearly a year and a half ago. This young fisher kit is looking good and has grown into a beautiful wild female fisher!
Her mother F31 was killed less than 2 years ago while she was nurturing the kits in a tree den during the denning season. The Fisher Science Team had been tracking F31 so they were able to locate and rescue the kits. After the kits were rescued from their mother's den tree, they were raised as part of a joint effort by the California Department of Fisher and Game, the Fresno Chaffee Zoo, and a local wildlife rehabilitation group (Fresno Wildlife Rescue and Rehabilitation), along with two kits rescued from a separate mortality incident.
Annie had been tracked until recently by way of a surgically implanted radiotransmitter, but that device ceased transmitting about 45 days ago and she was temporarily lost to the study. So, when we recaptured Annie last week it was great news!! She was very healthy and has established her own territory inside of her mother’s former home range. We are particularly excited that we should be able to track her during her potential first denning attempt this spring. We look forward to tracking her movements during her second year of life.
We are also fortunate to be tracking Mowgli, the male sibling fisher kit released with Orphan Annie. Mowgli is now a strapping young male fisher surviving on his own and we call him M27. Mowgli had been missing since spring of 2011 when his radio collar fell off, so it was very exciting to relocate him as well. Like Annie, Mowgli appears to be very healthy and should be ready to engage in mating this spring based on his large size.
The second mortality incident involved F25, another female fisher our team had been tracking when she died after being struck by a car on a local highway. When F25 died she left behind two other orphan fisher kits in a nearby den tree; F40 (Zosi) and F41 (Paya). F40 was killed in Jan 2011 shortly after her release and F41 has been missing since April 2011. The team is now strategizing on ways to access the area F41 had been using on the south side of the San Joaquin River near Mammoth Pool dam for a trapping attempt. The area where F41 had established a home range is very difficult to access from the north side of the San Joaquin River, so trapping there will be a major logistical challenge.
Ophan Annie January 2012
Mowgli in January 2012