The continuing quest

The biggest blue blossum (Ceanothus thyrsiflora) I've ever seen (uprooted by the storm)

The weather forecast was for sunshine on Thursday, so I drove to Arcata on Wednesday.

It drizzled on and off the next day.

Spring storms had uprooted a few trees, but spared the video camera in the fir tree.

When I reached it I saw worrisome droplets of water inside the Fresnel lens over PIR sensor, but my paranoid fears were for naught, the camera was still perched on the limb.

After unscrewing the lag bolt I took a close look at the tree vole nest, and realized something had destroyed it.    

The nest cavity had apparently been only an inch or two under the surface of the fir needles, but it was no longer a solid mass. The core of the nest had been torn apart. 

We retreated to the truck, uploaded 12 video clips to my laptop, and found only 2 contained footage of the vole.

The other clips contained other arboreal visitors.

What follows is not exactly action-packed, and the jury is still out as to the identity of the nest wrecker.

But if you want to see the voles and the suspects, have a look.

Another Arboreal Adventure and PSA Syndrome

Sonoma tree vole diorama, Photographer Gabriel Moulin,
courtesy California Academy of Sciences Archives. 

Fifty years ago the red tree mouse diorama at the California Academy of Sciences looked like this*. 

Periodically I would visit and stand there spellbound.  

Like the mossy gym sock exhibited in the same hall, the tree mouse diorama featured an intriguing nest with red-haired mice disporting themselves like sugar plum fairies.

I knew that some day I would find one of those nests. I was certain that I would know one when I saw it. 

Little did I know a half century stood between my youthful ambition and its realization, but faithful readers of this blog already know the codger encountered his first red tree vole a couple months ago.  

It was a fleeting engagement and not particularly satisfying.

The nest was a pathetic example of mouse work, a paltry accumulation of fir needles balanced over a recess in the trunk, and the resident's activities were usually out of the camera's view.  

I needed to find a brood nest like the one above -- an overstuffed cushion of fur needles, a spacious stage where a mother vole performs her nocturnal ritual and little voles play in the moonlight.

A week ago we resumed the search and wandered the logging roads with slack-jaws and craned necks looking like crazed birders.      

Nests we found, and some were even in climbable trees, but all were beyond reach unless you had a cherry picker or a very well-trained monkey.

They looked like tree vole nests, but only a fool
or a monkey would climb them to find out.

The afternoon was wearing on and I was ready to admit defeat when we wandered off the road into a young stand of Douglas fir, and there it was about 35 feet above us --  a messy tangle of sticks and fir needles right next to the trunk. 

Fresh clippings and resin ducts told us the nest was occupied.

It was an excellent climbing tree with whorls of reasonably stout limbs -- living limbs mind you, not the rotten ones so common on older trees. Terry fetched the ladder while I admired the tree and yammered about its suitability.

My first ascent convinced me that the climbing path needed a haircut. So dense were the springy wire-like twigs that I felt like a Lilliputian climbing a wire chimney brush.

That done, I drilled a hole in the limb and screwed in a lag bolt mount.

The camera was a HD video cam -- a DXG 567v with a small IR array home-brewed by the talented camera hacker "EgbertDavis" .

I dropped the camera stem into the mount, adjusted the camera angle, opened the back one last time, and powered it up.

Having tested the camera on wood rats last fall, I knew the infra-red illumination wouldn't bleach the subjects at close range.

Terry and I made 5 camera trap sets that day, but this was the set that haunted my reverie as I drove up the Trinity River Canyon on my way home.

Then the car radio lost its reception and disturbing thoughts started to seep in.

Had I tightened the wing nut enough to maintain the camera angle? Would the wind buffet the camera, cause false triggers, and fill the SD card with useless footage? And how long would the batteries last?

Two nights later a big storm blew in off the Pacific.

I emailed Terry: "We've been getting heavy winds and rain, and I'm a little worried about that cam in the Doug fir. Hopefully it is sitting tight".

"We had wind gusts up to 40 mph", he answered "and last night got a big hail storm which lasted about 10 minutes".

I envisioned the fir's limbs whipping furiously in the storm, and then I saw the distressing aftermath -- a heap of broken boughs and my DXG lying on the ground.

Manic expectation, doubt, worry, disillusion, chagrin, and finally the blues -- this is the emotional roller-coaster called camera trapping.

As for the haunting doubt and worry -- I guess you can call it Post-Set-Anxiety Syndrome.

+++++    +++++     +++++

*/ Of course, the wire mesh and support structure wasn't visible; the photo must have been taken when they demolished the exhibit.

A hard-to-get tree vole

Arborimus pomo, the Sonoma tree vole

At last the hard-to-get Sonoma tree vole, the secret of the Douglas fir forest, the mainstay of Northern spotted owls was captured in pixels.

I hope you are sitting there in wonderment as you view the seldom-seen rodent at work in its nest 35 feet above ground.

And if you want to fill in the picture conjure the feel of the damp coastal air, the woodsy scent of conifers, and the murmur of the Mad River.

The cams had been in the field for 70 days, but the batteries in this one called it quits on November 20th, only 18 days after we made the set.

But 267 images is still a good haul, so we uploaded to my laptop on the tailgate of Terry's pickup, and as we flipped through the images we found that the vole's nest had a life of its own.

Indeed it expanded and deflated like a slumbering mini poodle, and several shots showed a centipede and a millipede grubbing about in the midden of resin ducts and twigs.

The tree vole on the other hand exposed itself in only 10 pictures, and of those only two were full body shots.

She revealed her tail and slender hips,

A full frame view of the nest of Douglas fir needles with the vole hauling a Douglas fir sprig.

but most of the time she was hauling and hidden behind twigs of Douglas fir.

A cropped view of the vole from the photo above. 

Back home I retrieved my Arborimus file and found that our modest success was a far cry from that of Eric Forsman and his colleagues at Oregon State University who studied the related red tree vole (Arborimus longicaudus).

Using a commercial video camera system they captured and analyzed over 300 days of videos totaling 6700 hours, and refuted the belief that tree voles are "slow, docile and somewhat clumsy climbers".

That dubious reputation was based on observations of sleepy and confused tree voles that had been rousted from their nests during the day.

On the contrary, they found that foraging voles "were often so rapid it was hard to follow them as they scurried in and out of the nest."

That speed explained why over 95% of our pictures were blank; the rodent activated the camera trap's sensor but was usually gone when the shutter released.

As for the changing size of the nest, successive photos show resin ducts accumulating at the top of the nest and then sliding down.

It seems the vole's favorite feeding perch might have been just above the camera's view.

One of these days we'll take on the tree vole with a video camera, but I make no promises as to when.

I have two DXG 125s on the work bench, but hacking an HD video camera is far more intimidating than a point and shoot camera.



Reference

Forsman, E.D., J.K. Swingle, and N.R. Hatch. 2009. Behavior of red tree voles (Arborimus longicaudus) based on continuous video monitoring of nests. Northwest Science, 83(3):262-272.

On the road

Bigfoot statue at the Bigfoot Museum
in Willow Creek. 

The codger's spending more time on the road.

The 8 hour drive to Chimineas wasn't enough.

I extended my camera trapping range north to Humbolt County, the fog belt, California's NW coast. 

The charisma of the red tree vole made me do it.  

This corner of tree vole country is 250-road miles from home, and for half of the ride I track the winding course of the Trinity River.





This is also the heart of Bigfoot county, but the only big feet I saw were those of middle-aged men in waders.

They leave their pug marks between the road shoulder and the banks of the Trinity.

Trinity River with middle-aged men in waders.

The ride to the Chimineas Ranch on the other hand is even longer -- 400 miles from home -- and the scenery only gets interesting the last hour or so when you leave Rt 5.

I prefer the ride to Humbolt County, where I am not vulnerable to the uncanny physiological effect of wide open space on the weight of my accelerator foot.

A few months ago the codger fell victim to this phenomenon on a remote stretch of highway, which caught the attention of an officer of the California Highway Patrol.

It wasn't far from where James Dean met his ending 56 years ago.

I thanked the officer with mixed feelings and drove home in a blue funk.

I paid the fine, paid the fee to attend on-line traffic school, and read the lessons every morning over coffee.

When I passed the written exam the burden of guilt and worry disappeared.

The codger no longer races with the flock down Rt 5.

He looks like a lame old goose in the right lane, cursing the 18 wheelers.

And when he crosses into the fast lane he lives with the ire of Nascar impersonators who ride his tail, flash headlights, sneer, flip me off, and pass in a huff.

No longer does he just look like a codger.

Now he truly drives like one.

It makes for long and trying road trips.

My adventures are reserved for the woods. They begin when I arrive, not when I hit the road.

Meanwhile, the ongoing quest for tree voles continues.

If you are interested, read one of my old buddy's accounts in Rivers Wind Notes. 

How to find a tree vole's nest

I had the pleasure of meeting Lowell Diller and his staff last week at Green Diamond Resource Company.

This is California's NW coast: redwoods, Douglas fir and banana slugs, the rain forest.

Appropriately, it was raining.

Lowell gave me a lesson in finding tree vole nests.

Drive very slowly with your head out the window, one eye on the road, and one eye on the canopy.

Note: we were on a restricted dirt logging road.

Don't try it on winding roads with traffic, like the coast highway.

When you find what looks like a nest made of fir needles scope it out with binoculars to see if it is occupied.

A mass of brown Douglas fir needles means it is vacant. A spotted owl might have nailed the occupant, or the vole just moved on.

If it is littered with green sprigs of fir and green resin ducts you probably have an active nest.

Diller is a pro at it, but it didn't take long for the codger to catch on.

When I spotted the atypical nest below, I passed the final exam with flying colors.