Video vision in the tunnel - Part 2

Our first attempt at subterranean video this year was disappointing.

Had the camera been placed differently the footage could have been better, but there was also the problem of the curious bear cub that dismantled the set.

The subterranean action however was more than enough to call us back.

Our second attempt in August was in a different segment of the same mountain beaver (=showtl) tunnel.

This time I came prepared with a customized mount that could be spiked into the hardpan on the floor of the tunnel and nailed into the log embedded in the silt bench above the tunnel.

Set 519.3 after being disguised
with a large flake of red fir.

The camera post was spiked and wired
to the embedded log. 

We covered the vertical hole with a large flitch of wood.

As you have seen in Part 2, the bear didn't show, and if any subterranean critters bumped into the camera they didn't move it.

















But I still didn't get the angle of the camera quite right. It should have been aimed up into the tunnel. The focus was also off, and the microphone made hideous sounds (which I'll try to remove -- sorry about that).

The camera in situ as we uncovered it
33 days later.

I just replaced the lens of the DXG 567v with a 4mm wide-angle CCTV lens, which will take in a much wider view.

We'll try again next spring.

Aplodon's watery subway

Aplodon's watery subway in a small lush grassy area 

with an abundance of lupine, Sierra County, CA.

As far as I can tell, mountain beavers don't mind watery tunnels.

Most of their burrows are in relatively moist soil, and on slopes where soil drainage is good.

A relatively dry Aplodon burrow 

between roots of white alder. Sierra County, CA

But in some burrows water trickles freely.

The green vegetation inside indicates an active burrow.

A new acquaintance in Sierra County showed me this tunnel system, where at least some sections of the burrow rest right on the water table and just a few inches below the surface.

These little charmers do some serious root grazing to clear a passage right under the sod, and I imagine the remaining root mass gives them a good coat brushing every time they scoot down the tube.
 
My friend discovered this colony in an unusual way. 

He was driving up the highway when he saw a bush making its way across the asphalt.

It wasn't on fire, but it was a strange vision all the same and it led him to a small Aplodon colony just above the road shoulder.

The rodent was removing bush lupines across the road and hauling them to its burrow on the other side.

This bush hauling business isn't unusual. You commonly find alder branches curing near their burrows.

Earlier this month I asked a Plumas County resident if he had ever seen mountain beaver. 

He paused a moment and said, "Yeah, and I shot it".

OhmyGodHowCouldYouAndWhy?!

It was cutting his bean plants and hauling them away. 

Since then the colony on his property hasn't gotten into trouble. 

But back to watery subways. 

When I was camera trapping for these fellows in Point Reyes National Seashore (check here) I got the impression that the most active burrows were near wet lush places. 

In early summer the active burrows were widespread at the bottom of the ravine.

They riddled moist soil and boggy areas beside springs, and above ground the vegetation was green and rank.

When the vegetation had dried up and much of the ground was drier in August and September there were fewer active burrows to be found.

Curing haystacks (in this case lupine) 

are a sure sign that Aplodon is working the area.