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Native Californian, biologist, wildlife conservation consultant, retired Smithsonian scientist, father of two daughters, grandfather of four. INTJ. Believes nature is infinitely more interesting than shopping malls. Born 100 years too late.

Saturday, February 8, 2014

A White Winter Weasel

The short-tailed weasel or ermine, Dec 19, 2013, 1840 h

I just scratched the white winter weasel from my camera trapping bucket list. 

At least the white short-tailed weasel (Mustela erminea). 

The white long-tailed weasel (Mustela frenata) remains to be camera-bagged.

White weasels of course are just brown weasels camouflaged in white winter coats. 

You find them where you can rely on long snowy winters, which is north of the 40th parallel.  On the mild west coast, the white-weasel-line jogs north into British Columbia.   

I bagged my white weasel near Yuba Pass on a steep north slope, in a jumble of broken granite shaded by red fir.

Some time in the past a large mass of granite cleaved and released a large flake of stone that slid several feet and settled against its mother.

The result was a narrow slot, a shelter, the kind of place small boys and codgers in their second childhood love to explore.

I was ready to camtrap "the granite flake" two summers ago, but a yellow jacket nest changed my mind. 

It was only the size of a grapefruit, but big enough to scare me off.  

The nest was gone last fall, so I set the camera on October 8th using civetone and castoreum as elevated scent lures.  

View from north opening.
View from south.

Bill and I checked it last Wednesday. The Lithium AA batteries lasted 94 days, and in addition to the white weasel -- here's what we got: 

Montane vole (Microtus montanus): 6 visits/8 photos

Bushy-tailed wood rat (Neotoma cinerea): 8 visits/13 photos. Last visit:Oct 18. Here it gathers lichen as nest material and/or food.

Brush mouse (Peromyscus boylii): 58 visits/146 photos. Many photos recorded one or more of these characters gathering papier mache from the wasp nest.

Trowbridge shrew (Sorex trowbridgii): 1 visit/1 photo (Nov 14)

Long-eared chipmunk (Tamias quadrimaculatus): 11 visits/14 photos (Last visit: Nov 21)

Chickaree (Tamiasciurus douglasii): 11 visits/14 photos 

You all know, of course, that we're in a bad bad drought.

There was little snow on route 49 until we reached 6000 ft. Normally it would be down to 4000 ft.

Below the current snow line those white winter weasels are an advertisement to predators, mainly carnivores and birds of prey.

Not to worry my friends, the furry and feathered agents of natural selection have already started to fix the problem.

[thanks to "Bill W, MJC" for the good company and watchful eyes]


King, C. 1990. The natural history of weasels and stoats. Cornell University Press, Ithaca

Hall, E.R. 1951. American weasels. University of Kansas Publications, Museum of Natural History 4:1-466.


Woody Meristem said...

Those are great catches from a good camera trap set. Congratulations on getting your white weasel!

JK said...

Great set Codge. Those small mammals really framed themselves nice for you. Next time we are up there you'll have to point out this spot. You picked up the camera just in time huh? Finally a decent storm coming through. Time for Salamander hunts in the Santa Cruz Mts.

Camera Trap Codger said...

Thanks, guys. I'll show you the place Jake. This is the 3rd weasel I've gotten there -- all using castoreum. Hope you find some adult Dicamptodon -- they're good luck in my book.

randomtruth said...

Another home run. Getting weasels is heard enough, but also getting a great pose and the winter whites? Grand slam.

That area is such a treasure. Looking forward to haunting it again this year.

Anonymous said...

Great pics in your latest post!!!


Anonymous said...

Lots of nice photos. Good work.


christian said...

Awesome set.

Trailblazer said...

Wow! Nice catch on that weasel!

Henry said...

It's nice seeing a weasel in white. Is it the flash causing the blue eyes? It looks cool :)

You really are the king of the shrews!

Camera Trap Codger said...

Not sure, Henry, but I think they may have a bluish white eye shine in darkness. The are neat little critters, and no matter how bad the picture, I always get a thrill when I camera trap a weasel.

randomtruth said...

Their eyes shine blue-green in spotlight surveying too. A random thought for ya from the physicist, Codge - since color is the reflection of that wavelength back to our eyes, and thus also the absorption of the other "missing" visible wavelengths/colors, perhaps the blue-green shine is showing you a clue to their ability to see into the infrared spectrum. Evolution has shifted their vision, and the blue-green end of the visible spectrum (nearer ultraviolet) has been dropped in favor of more coverage on the infrared end. And thus their eyes now reflect back blue-green, an "un-needed" color for their vision.

Camera Trap Codger said...

Wish I knew, Ken; I do know that eyeshine can change depending on angle of incident light -- I have a coyote photo that shows different colors in each eye, and in a second photo the color is the same. The tapetum lucidum is the reflective layer behind the retina, an adaptation for night vision, but I don't know how the reflected wave length affects color perception in the rods and cones. Nocturnal carnivores are supposed to have rod and dichromatic vision -- not sure of the latest finds in this field. I think bears have some color vision, and recall that house cats are similar.

Owlman said...

Great photo and also a perfect spot. Congratulations Codger!