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Native Californian, biologist, wildlife conservation consultant, retired Smithsonian scientist, father of two daughters, grandfather of 4 small primates. INTJ. Believes nature is infinitely more interesting than shopping malls. Born 100 years too late.

Wednesday, September 2, 2015

A saga of the meat bees

The remains of the hornets nest after the skunk's first visit.

"What's wrong, Silly Boy?"

A bewildered Fred had just slinked into the garage and crawled between the table saw and work bench.  

Yellow jackets were crawling in his coat like raging ninjas, probing for dog hide with their stings.

I dragged him out from his hiding place, slapped the spiteful insects, and stomped them on the floor.

We had coexisted all summer with a nest of "meat bees" next to the house, and I had a hunch that Fred had roused them by scratching a dirt bed near their nest.

Sure enough, they were swarming, and I was their next victim.

Only by peeking around the corner of the house could I survey the ninjas safely.

There was no sign that Fred had been scraping a dirt bed.

Then the ground heaved ominously near the nest entrance.

Was a squadron of killer wasps about to erupt?

The ground lifted several more times, tracing a path away from the nest, and suddenly it dawned on me: 

I had just witnessed a rare event -- subterranean predation!

A mole had torn into the meat bee's underground fortress.

Maybe it had the sweet taste of meat bee larvae on its lips, but this mole was beating a hasty retreat from the yellow warriors.

To prove my supposition, I really should have grabbed a shovel, flipped that mole to the surface, caught it, and taken a picture while fending off the meat bees.

I might have tried it in my youth, but the codger was satisfied to marvel at the image of the mole breast-stroking through dirt with mean-assed meat bees stinging his velvet keister. 

Yes, moles are known to feed on the larvae of underground hornets. The paper mache nest is no defense to a hungry mole that scents a comb of tender wasp larvae.

Anyway, the meat bees had to go, because I wanted to see what the mole had done to the nest.

Neighbor Larry delivered some wasp spray, and the next day I donned my running shoes and zapped the nest entrance.

A few dead wasps littered the ground the morning after, but the ninjas were still coming and going. 

I gamely sprayed again, expecting to excavate the next day.

I was ready to start digging until I heard the menacing hum of meat bees underground. 

I sprayed several more days.

Finally the hive was silent, and I began to scratch away the overlying dirt. 

I found the mole's tunnel, and carefully uncovered the domed gray paper roof of the meat bees' inner sanctum. 

The caress of the rake brought them back to life again! 

It took a full week to annihilate the colony, but the coups d'grace was apparently delivered by a skunk. 

The scene looked like someone had taken a small rototiller to the nest.

I buried the remains of the nest and smoothed the surface, but the skunk dug it up again that night and the next. 

Ah, what a saga . . . Hungry mole attacks nest of meat bees, meat bees mount courageous defense, homeowner and dog become co-lateral damage.

Homeowner vainly wages chemical warfare, and a skunk finishes the job, proving that Old Stinky eradicates meat bees better than moles or the petrochemical industry. 

Wednesday, July 8, 2015

Bagging a little impersonator and other surprises

The shrew-mole, Neurotrichus gibbsii, with its flexible nose-probe in action.

"I'm goin' for shrews", I told my friend Terry who lives in California's Humbolt County.

The fog-bathed redwoods of California's north coast is the land of banana slugs, giant salamanders, red-tree voles, and shrew-moles, among other zoological wonders.

A Sonoma Shrew matches the color 
of redwood duff. 
My assertion that I was going to camera-trap shrews was a bluff.

I was hedging my bets.

I knew Terry's cat, "Muir" periodically catches shrews in the garden, and the cinnamon-colored shrew on the left is proof.

I also knew that kneading sunflower seeds into leaf litter and humus attracts shrews as well as mice and rats, and I submit the photos below as proof.

Sunflower seeds lured these Canadian and Alaskan shrews to my camera traps last summer.  

That afternoon we set camera traps (Sony s600s and Pentax Optio E60) in the redwoods, and the next morning found that the plan had paid off.

The pictures were short on resolution but good enough to identify two of the three "Soricomorphs", or "insectivores" as they were once called.

The Sonoma shrews were easy to identify by color and size.

A Sonoma shrew (Sorex sonomae) face-to-face with a baby millipede
(the pale elongate object in front of it).

The other shrews were either Wandering shrews (S. vagrans) or Trowbridge shrews (S. trowbridgii), which look identical unless you give them dental examinations.

My big thrill however was "bagging" a shrew-mole.

This is the world's smallest species of mole, but it's an excellent impersonator of shrews.

There's no question it's a mole; the quintessential mole-features are there in the teeth, skull, and the absence of external ears.

Its scaly tail with black bristles and constricted base is also decidedly un-shrewlike.

At some point in its evolutionary passage the ancestral shrew-mole struck out on an independent path.

It either lost or never acquired the other features of its family -- the over-sized "man-hands", the velvety pelt, and the predilection for subterranean foraging.

The transformation gave us a mole that can't "swim" the soil with the talpid breaststroke, doesn't makes mole-hills, and lacks the napless and velvety mole pelt that once adorned Yankee waistcoats.

Shrew-moles walk on the soles of their forefeet, which is impossible for moles to do, and sometimes they walk on their knuckles, like anteaters, armadillos, and gorillas.

What's more, they can stand bi-pedally like a squirrel and climb into low vegetation, which moles can't do.

And then there's the mole-snout.

Shrew-moles perfected it as a somewhat flattened and flexible walking stick with lateralized nostrils.

The foraging shrew-mole taps its nose center, right, and left with each step.

Dalquest and Orcutt, who studied the species nearly 80 years ago reported that the snout "may be thrown high in the air, twisted to one side or the other, rapped on the ground, or hooked under the body."

When it sniffs out a sowbug or earthworm, the shrew-mole thrusts its nose, and hooks and pulls out the prize like little Jack Horner.

The photo below seems to show it nose-plucking sunflower seeds the same way.

A shrew-mole roots for sun-flower seeds in redwood duff.

Most of the photos were false-triggers probably caused by something scurrying through the frame before the shutter fired.

I was hurriedly clicking through these "blank" images when the time-lapse effect revealed a Brownian swarm of pale larval millipedes.

These I assumed were instars of the yellow-spotted millipedes (Harpaphe haydeniana) so common in the area.

An immature miilipede or instar, presumably
the yellow-spotted millipede. 

In one frame a shrew rooted sunflower seeds in a flock of 12 baby millipedes.

In another frame two dozen baby millipedes grazed together peacefully.

It was like a miniature Serengeti with hunters and hunted drifting on and off the stage of life.

Wow, I had made a discovery!

"No wonder there are shrews here, there's an endless supply of tender nourishing millipedes."  

Or so I thought.

Yes, they looked like "easy pickins", but were they shrew fodder?

It was time to search the literature.

I found that Robert Stebbins, the late and great herpetologist once dropped a couple of millipedes (Tylobolus stebbinsi) into a jar containing a western skink, and despite the lizard's predatory restraint it was dead in 3 hours.  

Millipedes look meek, but their "repugnatorial glands" are highly effective weapons of chemical warfare.

Their many-segmented-bodies are equipped with stink glands, which can be selectively activated to release any number of noxious gases depending on the species.

The gas has a distracting effect on predators such as mice and birds, which immediately lose interest in their meal, blink their eyes, plow their faces in the soil, and go into fits of self grooming.

Yellow-spotted millipedes produce hydrogen cyanide which in low concentrations has a pleasant almondy-smell  (and gives me an appetite for Danish pastry).

According to Bug World the species is toxic to shrews.

Are immature stages also toxic, or as toxic as adults?

Millipede specialist Bill Shear informed me that baby millipedes can produce toxins as early as the 3rd instar.

At this stage of development they are probably too small to interest shrews or shrew-moles as food.

This probably explains why the myriad baby millipedes safely grazed while the shrews ate sunflower seeds nearby.

"When frightened, Neurotrichus makes an unbelievably swift, scuttling dash for cover."
(Dalquest and Orcutt, 1944, p. 391)


Dalquest, W. AND D.R. Orcutt. 1942. The biology of the least shrew mole, Neurotrichus gibbsii minor.   American Midland Naturalist, 27:387-401.

Eisner, T. and J. Meinwald. 1966. Defensive Secretions of Arthropods. Science, 153, No. Shear, W. 3742:1341-1350

Shear, W. A. 2015. The chemical defenses of millipedes (diplopoda): Biochemistry, physiology and ecology. Biochemical Systematics and Ecology, 61:78-117.

Stebbins, R.C. 1944. Lizards killed by a millipede. American Midland Naturalist. 32 (3):777-778.


Many thanks for Dave Rentz, Petra Sierwald, and Bob Mesibov for leading me to Bill Shear, who kindly shared with me his excellent and fascinating review of millipede chemical defenses.  

Thursday, June 25, 2015

A white-breasted nuthatchery

I hope the incubating nuthatch in this box was satisfied with its mates' choices of carry-out.  

During incubation he served his lady a lot of legless carpenter ants, and she accepted them eagerly. 

Occasionally he served her a red ant, but . . .

the mainstay was caterpillars (which Mr Smiley identified as those of noctuid moths).  He also delivered shelled sunflower seeds from our bird feeder.  

He was a bit of a show-off. His acrobatics were eyecatching, . . . 

  but he didn't hang around after deliveries. 

I was puzzled by the occasional delivery of squirrel fur, a feather, and perhaps paper mache from wasps' nests. 

At these times he was also photographed peering into a gap in the box. 

The old nest box was coming loose at the backboard, and I gather the materials were intended for nest maintenance -- an attempt to chink the gap with fuzzy bird oakum.  

Finally the hen appeared with a fecal sac, and I knew the eggs had hatched. 

Apparently she made hasty exits, because the camera trap never caught this action again. 

When the chicks hatched, spiders and small beetles were added to the mainstay of caterpillars . . . 

and then moths replaced caterpillars.

The camera snapped one youngster the day before the family suddenly disappeared.

Except for yellow rubber-band lips and short tail, junior looked just like its parents.

The little imp also looked vulnerable, especially clinging to the box.

The next morning . . . (insert a heart-rending "oh no" here) . . . my camera caught several images of a Steller jay on top of the nest box.

I immediately checked it out with a flashlight.

The box was empty. There were no nuthatches at the feeder either.

I started to think the worse. Did the jay eat the fledglings? (Of course it did, you damn fool. Wasn't it just there, looking for more?)

It would have been so easy to nail the little buggers, and that's probably what happened. (Hey, you're a biologist. This is how it works.)

Two weeks later four nuthatches showed up at the feeder.

If the jay dined on tender nuthatch, it didn't get all of them.

Thursday, June 18, 2015

Scree in Winter

Deadman Lake and its scree, on the north facing slope of Rt 49 (Google earth image)

You are looking at Deadman Lake at 6675 feet, and its ancient field of scree that spills downhill nearly 700 feet.

A camera set in deep boulder-scree
We set camera traps on Deadman's scree slope last November.

It's a strange place.

In summer you can slow-fry eggs on the sun-baked boulders, while cool drafts and the babble of moving water rise from the depths. 

In winter it's a wasteland of ice and snow,  

We've camera trapped Deadman in summer and fall, when little chief hares or pikas raise their squeaky alarm.

Scree isn't plant friendly, and you wouldn't expect many small mammals other than pika to live there.

But we've photographed wood rats, deer mice, chickarees, chipmunks, and golden-mantled ground squirrels far from the more vegetated edges.

The presence of those critters convinced me that talus must be a winter paradise for weasels.

It offers ever-present protection from the elements, thousands of recesses to escape from hungry raptors, and a steady supply of food.

Normally Deadman starts to look glacial in mid October, but winter was late last year.

We managed to get our act together in early November, and set our camera traps in shirt sleeves on a fine Indian summer day.

Six months later we were casting about and scratching our heads looking for our cameras.

I was the one who couldn't find his cameras, and even with the GPS telling me I was there I still had to peer into deep recesses to find two of them.

The camera batteries had died months earlier in most, but two of my cameras set a new record of 6 months -- they were still running on external D-cells.

We didn't have much to show for our patience, and we didn't get a single picture of a white weasel.

But a bobcat made several appearances at the first cam I set at the foot of the scree.

Full frame of scree visitor

The space was too small for a full body shot, but the cat showed us both working ends. 

Another revealing view.

Sunday, April 26, 2015

Blond Pole Dancer

Neighbor Larry built a GoPro camera trap for me, and I finally set it in the woods.

My goal?  Color videos at the water hole at night.

The undertaking has been a challenge.

First, you need sufficient power to charge the power-hungry GoPro Hero2 and external LED arrays. 

Wireless lights would be ideal, but we're not there yet. So, after driving two t-posts into cracks in the bedrock, which happens to be volcanic capstone, I slipped on the pipe extenders, and wired the two arrays at a height of 6+ feet to the camera.

The rig looks like hell, and I knew it would be a standing invitation even to the dumbest bear in the woods.

Of course the inevitable happened.

A blond pole dancer showed up, and her provocative performance disabled the lights.

You've seen her before, if you've visited Camera Trap Codger in the past.

This 2-year female is almost certainly one of the two tiny cubs in the YouTube videos I posted in the spring and summer of 2013.

I think you'll agree, she's a foxy pole dancer. 

Tuesday, January 27, 2015

Squirrel Creek Campground

The view from the developer's lodge

Squirrel Creek Campground, Alaska -- August 19, 2014

We arrived in late afternoon, took campsite 16, and made the trailer ready for habitation.

While the redhead fed the dog, I made a recce to a large beaver lodge across the lake.

The trail soon petered out, but beaver skids and felled cottonwoods told me I was in a development zone.

It was the kind of development I like to see; so I turned back to fetch 3 cameras.

Again I beelined to the lodge, and found it gloriously covered with mud pies and giving off a strange gamey smell.

If that was the smell of castoreum it wasn't the beaver scent I use.

I set the infra-red video camera at the lodge, and staked the two still cameras at the beaver skids.

And I did a little experiment. I dabbed castoreum on the trail of the less active one.

A sudden splash caught me off guard!  Tail slapping. An insolent beaver was keeping tabs on me.  Three of them were cruising offshore.

Dinner was on the stove when I got back, and I was in my bunk when my wife reported that some men were coming through camp.

Two young guys with backpacks, fishing rods, and a big yellow lab on a length of logging chain traipsed past the trailer with the determination of Lewis and Clark.

They were heading right to my beaver sets.

I poked my head out the door.

"Hey guys!"

The first fellow just kept going.

"I've got several camera traps staked near the shore line."

The guy with the dog turned his head.

"Just want you to know the scent lure may attract the dog, okay?"

He looked at me with a slack-jawed expression, nodded, and was gone.

This was bothersome.

Suspicion and revenge scenarios flooded my thoughts. They passed through camp an hour later.

My suspicion was undeserved. I found my cams the next morning.

The video cam had failed -- a shame, because it looked like
they had a mud fight at the lodge last night.

Disappointment -- moisture on the lens
and wrong camera placement. 

And damn! The skid by the felled cottonwood was another failure; it had 9 blurry pictures of beavers hauling limbs toward the pond.

But the castoreum set came through with 130 photos triggered in 3.5 hours.

Okay, there were no prize winners, but at least the beaver was recognizable as a beaver.

Checking out the scene soon after I left.

Wading through the dew-drenched brush to check those cams was a delight, and the experience visited me with an afterglow during the long drive home.

Responding to the castoreum on the skid late later that evening.

We passed hundreds of beaver works along the Alcan and Cassiar Highways, and almost all of them called -- 'get in your canoe and check me out'.

I decided to spend some time appreciating beaver lodges in the Sierra Nevada when I got home.

Tuesday, January 13, 2015

Return of the Fisher

The football game wasn't going my way; so I decided to get physical and pull 3 cameras that had been soaking in the rain.

I headed up Skyway, parked the truck, mountain-biked a couple miles, surmounted a blow-down across the trail, and fell on my butt on the way down the ravine.

The first camera was dry, but three bears had bumped it off target during a  bumble-fest of scent-rubbing.

The news from the second camera was good and bad.

The bad news was the water in the case; it shorted a circuit and shuttered pictures like a machine gun.

The good news was a photo of a radio-collared fisher.

And the camera in the next ravine had more pictures of the same critter.

Discovering the scent lure
A good thing has happened.

California Department of Fish and Wildlife, the US Fish and Wildlife Service, and Sierra Pacific Industries (SPI) have joined forces to restore the fisher to the northern Sierra Nevada.

This radio-collared animal might be one of 40 fishers that were translocated from the northwest corner of the state to SPI land near Stirling City.

But it could also be one of the 48 offspring born to the colonizers over the past three years.

The historical occurrence of fisher in California has been a puzzle.

California's great academic naturalist, Joseph Grinnell, assumed fishers ranged throughout the Sierra Nevada.

Since Grinnell's time however, fishers were found to be missing from a 420 km section of the northern Sierra Nevada.

This "dead zone" is an enigma, because the habitat seems to have everything a fisher needs . . . a fisher-friendly climate, lots of trees, water, cover, squirrels, and maybe even a few porcupine.

Biologists have assumed that logging and trapping divided the population, leaving one in the southern Sierra Nevada and the other in the Trinity Alps and coastal mountains of NW California.

A recent study based on DNA from museum specimens and living animals tells a different story.

California's fishers became divided populations about 1000 years ago.

In other words, we can't blame the fisher gap on the Spanish colonization of California and the gold-lust-mayhem of the 49ers.

Fur trapping and intensive logging in the early 1900s, however, caused the continued decline of fishers across North America, and in 1946 California was the last fisher range state to enact protective legislation.

The two populations are now genetically different, which raises questions about their conservation.

Like, should we connect the northern and southern populations, and risk genetic pollution of their gene pools?

Or should we colonize the gap with fishers and brace the population against future environmental unknowns?

I rather like the idea of filling the fisher gap. California's just an experiment, isn't it?

Having a few more fishers around makes the place more interesting.


Grinnell, J. 1913. A distributional list of the mammals of California. Proceedings of the California Academy of Sciences, 3:265-390

Grinnell J, Dixon JS, Linsdale JM (1937) Fur-bearing mammals of California: their natural history, systematic status, and relations to man. University of California Press, Berkeley. 375 p.

Powell, RA. 1993. The Fisher, life history, ecology and behavior. University of Minnesota Press, Minneapolis. 237 pp.

Powell, RA,  RC Swiers, AN Facka, S Matthews, and D Clifford. 2013.  Reintroduction of Fishers into the Northern Sierra Nevada of California,  Annual Report for 2013 For the period of October 2009 to December 2013, 35 pp. 

Tucker, JM, MK Schwartz, RL Truex, KL Pilgrim, and FW Allendorf. 2014. Historical and Contemporary DNA Indicate Fisher Decline and Isolation Occurred Prior to the European Settlement of California. PLOS One 7(12):1-13


Gabriel, MW,  et al. 2014.  Anticoagulant Rodenticides on our Public and Community Lands: Spatial Distribution of Exposure and Poisoning of a Rare Forest Carnivore. PLOS One 7(7): e40163. doi:10.1371/journal.pone.0040163

Zielinski WJ, Kucera TE, Barrett RH (1995) Current distribution of the fisher,

Martes pennanti, in California. Calif Fish Game 81: 104–112.