Slinky grim reaper of the underworld

Long-tailed weasel with prey.

There's a good reason weasels are long and skinny.

It's "essential to the profession of a burrow-hunting rodent predator...", wrote weasel expert Carolyn King.

This photo of hunter and quarry was taken in a mountain beaver burrow, and it would seem to prove the point.

But did this long-tailed weasel kill the golden-mantled ground squirrel in the burrow?  Or did it dispatch the rodent above ground and then drag it into the burrow?

Golden-mantled ground squirrels are common in the area, but you find them in dry open coniferous forests rather than the riparian woodland and thickets where mountain beavers dig their burrows.

I've camera trapped this mountain beaver burrow almost seven months in the past 4 years, and the graph shows that golden mantled ground squirrels are not among its users.

I suspect the weasel killed the ground squirrel above ground and dragged it into the burrow to feed out of harms way. That's how weasels operate.

But as the graph shows, a weasel is more likely to encounter a mountain beaver in this burrow than a golden-mantled ground squirrel, and the chickarees and voles down there certainly run the risk of meeting this slinky grim reaper as well.

One other observation: the camera failed to record the resident juvenile and adult mountain beaver during the last sampling period. At least one mountain beaver has always been present.

Has the weasel appropriated this mountain beaver's underworld?

Is its nest now lined with the soft pelts of the previous residents?

I'll update you next month.

A chickaree shells a fir cone in the underworld earlier this month.

Reference:

King, C. 1989. The natural history of weasels and stoats. Cornell University Press, Ithaca.

Animal tracking whodunnit

Two codgers walking a dog encounter the scene above at 2:15 in the afternoon.  

Obviously, something killed Chicken Little, but there is no predator to be seen.

The codger's dog sniffs the carcass briefly but otherwise ignores the scene. 

The carcass is cold, the tail has been plucked, and the head has been pulled off.

The neck has been eaten, as well as the wings where they attach to the pectoral muscles.

The head is uneaten. 

Questions:

1) What species is Chicken Little?

2) What species killed Chicken Little?

3) Why didn't the predator take Chicken Little when it left the scene?

Coyote gets BT Jack

The coyote caught BT Jack in mid-June, and strolled past the camera 45 minutes before midnight.

BT Jack is the black-tailed jackrabbit; that's how I abbreviate the species in our data tabulations for the Chimineas Ranch.

A 5 lb jack rabbit is a decent meal for a 30 lb coyote, and this coyote seems to have already devoured nearly half of it.

Another coyote happened by but was less composed.

And the bobcat was a bit spooky, though it didn't depart till it had sniffed the bait under the rock.

Bobcat catches snake

Just back from checking the cameras in Marin County, and was pleased to get some images that showed more than bobcats walking away from the camera.  

I'm getting a little tired of bobcat butt shots. 

This photo was taken on July 2 during the heat of day -- 2:34 PM -- when snakes are up and about.  

Unfortunately, the shutter speed was 1/30th of a second, so the gopher snake and the cat's head are slightly blurred. 

The snake looks limp, which means it is dead, and the cat is no doubt looking for a place to settle down and feed.   

This is the same trail where the bobcat was seen carrying the dead brush rabbit. 

It cuts through coastal scrub and mixed conifer/oak woodland -- so it is good edge habitat, and bobcats frequently pass through. 

Skinny cat nails plump bunny

The young bobcat caught the brush rabbit on the evening of June 11.

I couldn't see the rabbit when I scoped the pictures on the camera's LCD the other day, but there was no mistaking it as a rare event when I saw it on the computer screen this evening.

I think the dead rabbit is the same one the cameras photographed between May 31 and the morning of June 9. (I have three cameras on this trail.)

No bunny however was photographed after June 11 and until I checked the cameras on June 30.

The rabbit had the habit of loafing on the trail. I got multiple images of it.



This trail seems to be on the cat's regular beat.



Between June 10 and June 23 the cameras photographed the same cat on 5 occasions.

Look at the it's right foreleg and you will recognize a distinctive broken band of dark fur.



It's the same in all photos, except the one with the dangling rabbit.



My guess is that the hunter is the same skinny bobcat seen in the other pictures -- a young adult probably from last year's litter.

The tail wasn't enough

...but was the rest of the meal too much?

I wonder.

When you find half an alligator lizard on the trail, you know the old tail autotomy trick didn't work.

Did the catcher of the luckless lizard lose its appetite or did something scary interrupt its meal?

A skinned skunk

[Skin, skull, and spinal column of the striped skunk. 

Leg bones with feet attached were nearby.] 

It's not often that you find a skinned skunk on the trail, but there it was.

Fred was sniffing it intensely. 

Whatever ate it, it dined fastidiously. 

The inverted hide is what you get when a predator pulls flesh from the torso and limbs while standing on the hide. 

Its hard to say what killed this skunk, assuming that it didn't die of other causes.

In this area, gray foxes, coyotes, bobcats, mountain lions, and great horned owls are the common predators reported to eat skunk, usually when quite hungry. 

I'd rule out mountain lion, because a large cat would have eaten the backbone. The same for a coyote.

A bobcat or a gray fox, on the other hand, would nip and shear the meat away from the backbone.   

My hunch? . . . we're looking at the table scraps of a bobcat or gray fox. 

Bobcat food

This is the area where the bobcat passed a few days ago.

Turkeys are an alien (=introduced) species in California, but bobcats and other predators have accepted them without prejudice.

The cam took 0.9 pictures/day here in 12 days, but the majority of the traffic was from this flock of hen turkeys and a couple of squirrels.



When I scoped these pictures out on the trail it was a ho-hum moment.

A couple years ago I would have moved the camera to a new location.

But sooner or later something less common will make an appearance.

So I'll just wait it out a bit longer.

I am not growing more patient. It's just that I have enough cameras now to work several locations at a time.

Dinner in the tall grass

[The leftovers of a coot dinner, Llano Seco, Butte County]

This was NOT a case of "death in the tall grass". 

The remains were next to an access road along a dike next to a canal of flowing water.

I believe the coot was killed somewhere nearby. The predator plucked it and ate it here.

The predator is unknown.

It could have been a raccoon, possum, otter, or mink . . . or a coyote or bobcat.

I'm ruling out raptors, because I would expect them to drag the prey into the open or fly with it to a roost.

Llano Seco is one of the smaller components of the Sacramento National Wildlife Refuge Complex, but it's the nearest (33 miles) to our house.

A victim of Nackenbiss

Check out the skunk's neck. Yes, yes, yes -- that's a mouse in its mouth (and a trespasser from my garage where no mouse is tolerated.) But that's not the point. I want you to look at the skunk's neck. Can you see that the wounds are on both sides of the neck?



Sooner or later those who live close to nature encounter the diseased and injured, and it sinks in that "nature is red in tooth and claw".

So how did this happen? I offer four scenarios based on the observation that the wounds look traumatic, rather than the result of irritation.

Scenario 1: The skunk got its neck caught in some chicken wire, and scratched itself trying to get out.
This is possible, but I don't think it is likely. No one in the neighborhood keeps chickens or keeps chicken-wire cages, and the chicken-wire under our deck has already been breeched and offers free and safe access to critters seeking shelter.

Scenario 2: The skunk suffered from a neck bite during a sexual tryst.
If we knew this to be a female skunk, and it was earlier in the year -- like January or February -- a romantic interlude would be quite possible. The courthip of mustelids (members of the weasel family) is well known for prolonged bouts of neck biting along with all the other stuff. But the breeding season is past, and little skunks should be appearing soon; so I don't think it is very likely. I might also add that I haven't seen wounds like this in skunks photographed earlier in the year when "love is in the air".

Scenario 3: The skunk suffered from a predatory encounter with a naive bobcat or coyote.
Many mammalian predators, especially cats and weasels, dispatch their prey with a neck bite which severs the spine. Note that this skunk shows wounds not only on its neck. There are also scratches on its head.



In this case the hypothetical predator might have lost its appetite when overpowered by skunk musk. This scenario is feasible. A naive predator might try to nail a skunk once, but the skunk's chemical defense and uniquely bicolored coat are highly effective teaching tools. Smart predators learn their lesson from a single experience. (Domestic dogs seem to require several trials, and some never seem to get it.)

Scenario 4: The skunk had a brawl with another skunk.
This would be more likely in male than female skunks. Carnivores tend to fight over food and sex. Since skunks don't have to defend their food (which comes in small packets), I suspect that studly skunks fight over females. Whether male skunks fight by attacking each other's necks, I just don't know. It seems possible, but perhaps a mammalogist out there can enlighten us.

We haven't solved the problem, but my guess is that the luckless skunk was attacked by a coyote, bobcat, or fox. By discharging its scent gland, it not only saved its own damaged neck, but taught one more predator that 'ole stripey' isn't to be trifled with. In other words, his own close calls and occasional misfortune benefits other members of his species.

[By the way, German-speaking ethologists identified the Nackenbiss (=neck bite) as a fixed action pattern. It is innate (=genetically programmed), typical of the species, and is tiggered by specific sign stimuli. It is used in predatory, sexual, and maternal situations with very different effects.]

Screech Owl update

Last week, after two days of no pictures and nagging fears that a squirrel had dined on screech owl eggs, I was ready to throw in the towel. I decided to wait a few days for my luck to change before going back to pull the camera. When I checked the camera yesterday I found 368 pictures (4 days worth) on the memory stick! Hallelujah!

There were no pictures of nestlings, but all signs indicate that there are young in the nest. Up till now, I never got a photo of two owls, and rarely got pictures of either owl going into the nest cavity. That's no longer the case.



And up till now, I only occasionally found pictures of the owls in the cavity. Now, 40% of the pictures were of the commotion in the nest cavity. There's a lot of flapping and excitement when the food is delivered.



Oddly, there were only three photos of prey: a Jerusalem cricket (or potato bug), and an insect larva.




Where are the mice? The woods are crawling with them. Or do dismembered mice invite blowflies and predators? I plan on keeping a camera on this nest until they fledge. Maybe I'll get a few pictures of the "fluffies".

Macavity Cat

My first glimpse of Macavity was back in February. I was puttering around outside when I surprised a large tabby cat slipping under the deck. My best falsetto "Here kitty kitty kitty kitty kitty. . ." had no effect. Joy. A new stray was here to prey on birds at the feeder.

Two days later the same cat dashed out of the garage when I surprised it gulping chicken parts consigned to the garbage. I had left the door open for only a few minutes, but Macavity had been watching and made his move. This cat clearly knew far more about us than we knew about him. When I didn't see the cat for a couple of months I concluded it had moved on.

Then one day about three weeks ago I was putzing about the garden, and I kept smelling cat piss. Wherever I went I would suddenly catch a whiff. I was on hands and knees sniffing for a scent post when the redhead casually observed that a cat had urinated on the polar fleece I was wearing.
"Isn't that the polar fleece you left hanging outside for the past few days?" she asked.
(How come women are so perceptive?)
She was correct, of course, and offered to wash it right then and there.
My woodsy codger musk had offended the cat, and my wife advised me not to leave it hanging outside anymore.

A couple weeks passed before our next encounter with Macavity. My wife needed help in the garden. An unknown mammalian herbivore had started to nip buds off the plants. I assured her that the codger could solve the problem, first by identifying the offender, and then by prescribing appropriate measures in behavioral modification. I set a camera trap in the patio.

The only mammal photographed (above) was Macavity on his nightly beat, strolling down the garden path to the back gate, looking confident and in fine fettle. The herbivory ceased and the plants started to recover.

Finally, yesterday I went to the potting shed and noticed a trail of blood and rabbit hair on the ground. I followed the drag mark through the leaves to the water tank. In the narrow space beneath the platform was a dead fully-grown black-tailed jackrabbit.

I put a camera trap under the platform, and this morning found 6 photos. Macavity returned to his prey at 8:12 PM, and apparently fed for 25 minutes. In the last photo at 1:18 AM he had moved the carcass closer to the camera. In the morning there was no trace of it.

The felid body plan is a design for killing warm-blooded vertebrates, and even a house cat has the equipment to take down prey as large as itself.

Who killed scrub jay?

The feathers told a story. Last night scrub jay met her demise. On the trail to the camera trap, I found a circle of feathers—blue flight feathers, and a few downy breast feathers. Unmarked, expertly plucked. There was a splash of white—the victim had been killed on the spot. No blood or body parts. Everything had been eaten there, or perhaps carried away.

One thing is certain. The killer was a professional plucker. Cats fastidiously pluck their prey, and I suspect that ringtails do too. Yes, it could have been an owl. Owls may swallow mice whole, but they pluck their feathered prey, though less painstakingly than cats. In their regurgitated pellets bird plumes are twisted among the bones. But I suspect an owl would have carried a dead jay to a perch, and the feathers would have scattered.

This looked to be the handiwork of a bobcat.

As I was hunkered over the evidence, I remembered hearing the jays rallying yesterday. They made a ruckus as I climbed the trail home in the long shadows of late afternoon. It was that irritating cawing of little crows. "Screeep screeep" ad infinitum. Scrub jays indeed have an annoying alarm call. I stopped to catch my breath and locate the noisemakers. I couldn't see them, but they were somewhere in the chaparral on the sunny south slope, perhaps 40 yards away. Was I the cause of their discomfort? Was my presence in the shadows so alarming? Come on, birds, give me a break.

But now, looking at the feathers in disarray, I connected the parts of the puzzle. A resting bobcat saw a man walking through the woods. The man was too close, the cat moved away. A scrub jay saw the cat, and sounded its alarm. Its family mobbed the cat, until it disappeared. The cat returned in the dark, and snatched a jay. It fed on it nearby. The man returned the next morning, and found the jay’s feathers in disarray.

The feathers told a story, and I think, perhaps, I played a bit part in the tale.

COMMENT: Protein starved killer squirrels

Within hours of posting "California’s gourmet squirrel", an esteemed colleague, Dr Robert Horwich sent this comment to my personal e-mail.

SUBJECT: SQUIRRELS KILL DOG

"You ain't seen nothing yet - check this one’r else. And be careful when you are in the woods. A good-sized pack of squirrels will pull you down by your ankles."

Dr Horwich included a forwarded link from the respected BBC. Read it--it reports on a pack of killer squirrels in the Russian Far East alleged to have slain a luckless hound.

Dr Horwich, who could be considered a "squirrel whisperer" was dubious that the squirrels actually attacked and killed the hound "…unless it was near death." He added, "They probably were just gnawing on the body like some of your observations."

Though squirrel bites can be painful, a dog dying of squirrel bites is as likely as a person dying from duck bites. While conceding that truth is sometimes stranger than fiction, my theory is that the three locals reporting the incident had impaired cognitive processes due to vodka.