Life in Fir

One of the many pleasures of cam trapping with the Codger around the SFSU Field Campus is that we get to do so in the incredible firs of the Tahoe and Plumas National Forests.

And sub-alpine white and red fir forests are fascinating ecosystems.

High above, a thick canopy of "leaves" only moose can eat (and there are none in CA). And if you can get up there, the flaky cones have tiny seeds that make pine nuts look hearty. Finally, on the ground below, in heavy shade - a debris field of fallen deadwood, with few understory plants.

And those understory plants - they're often parasitic - living life with few/no leaves, instead getting their energy through taps into the fungal and tree root networks beneath the detritus. A good adaptation for low light, heavy snow, and a short growing season, to be sure. But poor forage.


Red and white fir often dominate California's upper montane forests

 
Pipsissewa and Wintergreen

 
Snow Plant and Sugar Stick

 
Pine Drops and Pinesap

For pure herbaceous browsers, such as deer and rabbits, fir forests are boring places. They're restaurants with almost nothing on the menu - except them.

Instead, the food web in fir is centered around wood eaters, ala fungi, termites, ants and beetles, and seed/shroom/insect eaters, such as birds, squirrels and mice. And the eaters of those, of course, and so on, and so on.

For my set this late summer I pointed the cam at a rocky jumble, knowing from Codger-wisdom that they're the spots that draw critters - in the semi-uniform understory of fallen fir bits.


Cam trap set on rocks in dense hillside fir forest

First, let's get squirrely. A variety of Sciuridae live in fir forests, and 3 visited the rocky outcrop:


Young chipmunk - perhaps Neotamias senex, or quadrimaculatus


A fast moving Western Gray - not a common species in fir forests, preferring pine and oak


Young Douglas squirrel, aka Chickaree, Tamiasciurus douglasii

At night, a strange play occurred - Of Mice and Millipedes. Deer mice and Yosemite millipedes both roamed the rocks, with occasional encounters that didn't seem to make the mice happy. Lacking the abilities to bite or sting, many millipedes squirt cyanide-based compounds as a defense - perhaps that's the lesson the mice learned.


Deer mouse, Peromyscus maniculatus, & Yosemite millipedes, Californiulus yosemitensis

Juvenile deer mouse and millipede


Same juve deer mouse with ick-face after apparent millipede encounter

Along with the scurriers, a few birds poked their beaks around the rocks:


A not-so-early robin caught a caterpillar


A northern flicker hunted the rocks several times for ants or termites or like


And a Steller's jay paused to crest

Last, but in no way least, a golden bear passed through and schmutzed the camera:







Unfortunately, no pine martens or flying squirrels this year.

Maybe in 2013.

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References:

• SF State University Field Campus - Photographing Wildlife with Camera Traps
• The Camera Trap Codger - 2012 Workshop
• BugGuide - Yosemite millipede
• Calflora.org - Abies concolor, Abies magnifica
• Nature of a Man (this blog) - Just Another Manic Marten
• Nature of a Man (this blog) - Drinking from the Firehose

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