Please do not send Rick Sweitzer any more socks. He's got all he needs, thank you. "We received so many we're donating them to homeless shelters," says the University of California, Berkeley, researcher. "We're spreading the wealth."

The deluge of hosiery came after Sweitzer exhausted his own sock drawer and turned to the public to help him document the Pacific fisher, a secretive tree-dwelling relative of the wolverine and weasel that is so tough that it regularly dines on porcupine and beaver (although not, interestingly, fish). Fishers once ranged throughout the West Coast, but trapping and logging reduced their numbers to the point where environmentalists have fought for 12 years to get them listed as an endangered species. Sweitzer is trying to keep tabs on the population of perhaps a hundred fishers that live south of the Merced River in Sierra National Forest. That's where the socks come in. Sweitzer and his team fill them with road kill and dangle them from trees, and then motion-sensitive cameras snap away while the hungry mustelids tear the socks apart.

The U.S. Fish and Wildlife Service has promised to rule on protection for the Pacific fisher in 2014.