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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.

Thursday, April 26, 2007

More screech owls

After several days of adjusting camera position, I managed to get 4 more photos of the screech owl in flight (2.7% of 143 photos). I'm not finished with this yet. Now that I know the flight path, I'll try one or two more angles.

The nice thing is that the birds have habituated to the camera. Notice that now I am using the plural. A pair of consecutive photos of owls leaving the cavity proves that there is a pair, but I still can't tell them apart.

In this week's batch of photos there were still no images of owls carrying prey. I assume they are feeding away from the nest, but expect the male will deliver food when the female is incubating.

Does any reader of this humble blog know if screech owls regurgitate pellets away from the nest? Doesn't it makes sense for a nesting owl to keep the nest area free of cues to predators? There certainly is no sign of pellets in the vicinity of this nest tree.

Friday, April 20, 2007

Puma invasion

All I can say is, "this is getting crazy". Who wudda thunk you could get two photo sessions with pumas in the same month? Within 250 yards of your house?

So yes, when I viewed the pictures in the ravine this morning -- and found four images of a mountain lion -- well, the endorphins kicked in.

But let me give you the background. Last week on this day I smeared a dab of castoreum (beaver scent) into the moss, and then crushed a fresh sprig of cat mint into it. Five days passed, and the mice danced nightly for the camera (23 of 35 frames--yawn). Yesterday at 4:16PM the puma found the lure.

Her visit was brief. Twenty-six seconds later the camera snapped the last picture as she descended the leaning trunk.

When I got home (sweating like a little pig) my wife was gardening. "Four more pictures of a mountain lion." I announced casually. (That got her attention).

"What?" she said, as she stood up and turned to me.

"Just another four pictures of mountain lion", I repeated with a touch of ho-hum boredom. "Yeah, she climbed the tree to get at the cat mint."

[A little background -- earlier in the week, after I groused that we had the wrong kind of cat mint for camera trapping, my dear wife went to the nursery and bought me a pot of "catNIP mint" (Nepeta cataria). We have a couple patches of the less-effective "catmint" (Nepeta musinii) in the garden.]

"Well, I'm having second thoughts about that mint growing around here."

She explained at lunch that she didn't want mountain lions rolling around in catmint around the house. I tried reasoning with her--"I mean what's worse, a little crushed catmint? Or a bear that uses the hot tub?"

Now for photo analysis. My initial take on the photos was: "Damn, the camera was too close and too low." (I moved it away from the tree for the next episode.) At home, viewing the puma pictures on screen, I noticed that though she was a bit modest, she revealed enough to inform us of her sex. And in one shot I detect a wee bit of paunch -- indicating the wear and tear of motherhood. Then I noticed the divit missing from the left ear. I checked my photo of the statuesque puma that posed last December, but couldn't really see a notch in her ear. (If you want to see previous pictures go to the index and follow the puma thread.) Conclusion: we have here a primiparous puma (i.e., she's given birth once already) with a distinguishing mark (a notched ear).

I am not turning up my nose to pumas, but now I have more pictures of them than bobcats. Are the big cats preying on the smaller ones?

Predators are known to do that, you know. Well, when we have enough catnip mint growing around the place, I can do an intensive survey.

Wednesday, April 18, 2007

Recluse in the snag

Three days ago at 6:13 PM a squirrel climbed down the snag and aroused the resident screech owl (who looked pretty scary to me). During the next two nights the owl took 143 pictures of its own comings and goings. Or should I say owls? If there is a pair, I can’t tell them apart.

The cavity is in a black oak and looked unused. So I was prepared for disappointment this afternoon when I went to check the camera. For nearly two weeks I have been using a new toy -- a telescoping fiberglass pole -- to raise the camera up to the level of tree cavities. This tree was second choice.

I expected a bonanza of pictures from my first choice -- a much-pecked flicker-sized cavity about 25 feet up. It had all the signs of occupancy, except the presence of a bird. The edge of the cavity had been chipped away and enlarged recently.

It was a bear of a job getting the camera into position, because when it is 25 feet overhead you can’t really see exactly where the camera's sensor is in relation to the cavity. From one angle they look like they are face to face. Then you move uphill to confirm it, and the camera looks too low. So you make adjustments and check again. And again. The other problem is pole-wobble. Even when anchored with guy lines, the slightest breeze wobbles the pole, which fools the sensor, and the camera goes wild taking pictures of moving vegetation.

After failing with a cavity that had "active nest" written all over it, I settled for one that was 12 feet up.

It looked abandoned, but I got a nice surprise. There were many shots of the little guy checking out the camera and the scenery.

And then there were shots of it clinging to the entrance.

And (whoohoo!) I got three pictures of the owl in flight.

Now to improve the set-up so I can get that picture of mini-raptor with limp deer mouse in talons.

Tuesday, April 17, 2007

Red-tailed scavenger

I was surprised that the mother bear didn’t pull the squirrel carcass down when she and her cub visited this site on April 3. I had tacked the forebody to the trunk of the fir nearly 8 feet above the boulder. When I checked the camera 4 days later it was well-seasoned, but not fly blown.

Five days after the bears' visit a red-tailed hawk saw the carcass, landed on the rock, flew up to the bait, and pulled it down. This scavenging comes as a surprise. At this time of year you would think there's fresh meat around that a redtail would forego over-ripe carrion.

Friday, April 13, 2007

The thrill is gone

I was thrilled with my first pictures of a spotted skunk over a year ago. The chicken neck I had nailed to a mossy stump was intended for a grey fox, but the taker was the skunk. Its gladiatorial tango with the bait filled the camera's memory card. Six months passed before another spotted skunk encountered the cameras. I was ready for it, and baited it in with the patience of Sherlock. When I had exhausted the staging possibilities I had over two hundred pictures of one jazzed-up skunk climbing trees, disembowelling gopher carcasses, and digging holes to cache the meat.

Now I can't seem to escape the critters. The first time I saw this canyon live oak a diaphanous bobcat appeared momentarily in the crotch like a mirage. A week ago, when I finally laid my hands on squirrel a la camino I prepared the site with loving care. (Can't see the bait, can you?) Then I waited a week. Bobcat was no where to be seen, but Stinkarella was ready for action.

When she was done, her entourage of rodents was there to clean up the scraps.

Tuesday, April 10, 2007

A prowling predator

Weekly camera trap rounds begin on Monday morning. The first camera is right next to the house on a dirt road, so I don’t normally get surprises. But at 8:21 on Thursday evening a puma came a'marching up the road. As luck would have it (expletives deleted), the camera snapped the picture before the cat was at the optimal "picture perfect" distance. The uncropped photo shows the original frame.

It's not a complete disappointment. At least I can identify the animal, and it's entirely in the frame. Last year, partial pictures of animals were driving me nuts. I missed a spectacular shot of a bear, because the camera was too slow and the flash was too bright. The image would have been stunning if the bear's nose was in the frame.

I tried to rectify the situation -- changed the camera position, adjusted the PIR sensitivity for a longer detection distance, and tuned down the flash. I also put some brush cuttings on the road to guide the traffic past the camera at an optimal angle. Then I tested the set up by strolling up the road at the speed of a bear. All of that should have improved the chances of capturing the gah-gah image of bear, and maybe puma or bobcat.

But dumb luck deals its hand without prejudice. Sometimes you get a winning shot, too.

There's a new product on the market for homebrew camera hackers that should tip the balance in favor of good fortune. It's Pixcontroller's new RF wireless motion controller board, and it works in tandem with one or more wireless motion sensors set farther down and/or up the trail. The wireless motion detector acts like a scout. When it detects a critter down the trail, it signals the PixController RF receiver controller to get the camera ready for action. This will expand that fleeting window of opportunity as animals pass the camera. (Don't tell my wife, but this new item is on my research and development list.)

Back to speculation about the puma. Who is it? Well, it's a macho looking cat, wouldn't you say? I suspect it may be the offspring of the trim female puma I have photographed three times since early December (See Dec 2006 posts: "No poodles tonight" and "The owl and the pussycats").

Four months ago she had a big-footed and slightly spotty-colored sub-adult in tow. Since then I think his body has caught up with the size of his feet, and he has become more independent.

Saturday, April 7, 2007

The Big Sneeze?

Three days ago shortly after 5:00PM mother bear and cub visited this camera-trap set. They hung around for a half-hour taking pictures of themselves. What was the attraction? The Furfindr (a digital player) and a road-killed squirrel were hanging in the tree. The squirrel should have been the attraction, and the Furfindr should have gone unnoticed, because it was programmed only for playback after dark.

Well, Mama didn’t touch the road kill, but she obviously sampled the Furfindr. The camouflage tape was torn, and the end plug had been popped out. Fortunately, it didn’t taste good enough to eat. It still works.

Baby bear was also intrigued with the camera. There were bear ears in two of the 13 photos. The cub seems a bit large to be this year's youngster. If it was born last year, it was a runt that made it through the winter, probably by denning with its mother.

And what caused the big sneeze? Could it have been the camouflage tape? Maybe I should chew on the tape myself, and see if it has the same effect. Or is it a sneeze at all? The more I look at it, the more I think it is a plastic bag.

Thursday, April 5, 2007

Bean counting

Sometimes bean-counting is a necessity. In my former life as a science administrator my colleagues and I were required to count beans regularly. It started shortly after the new chief said he was going to get the scientists under control, and bean-counting became a job priority. We reported commonplace things that had been happening for years, and were reminded monthly to submit our reports to the bean-counting directorate. It was "busywork", and bean-counting became a critical factor in our annual performance evaluations.

Recently I drew upon my store of bean-counting expertise. A year and a half ago I had noticed small dusty patches near my house. I thought I had a problem -- erosion. Then I observed that each bare area had a few bunny beans mixed in the dirt. So I did what came naturally. I sorted the beans by age and counted them.

Two days later I returned and counted them again. The numbers had changed, and the fresh beans had increased in number! (The bean-counting directorate would have been pleased.)

Next, I set a camera trap. A week later I viewed the pictures and learned that the only visitors were black-tailed jackrabbits.

Each night one or more rabbits visited the bare patch, where they hung around and sniffed the ground for a few minutes at a time.

I didn’t get any pictures of the rabbits rolling around in the dust, so we can't call these places wallows. And so far I haven't found any references to jackrabbits counting beans.

As for the supreme bean counter back at the Smithsonian, a recent audit showed that he indulged in rather questionable bean-counting practices himself, and he decided to move on.

Tuesday, April 3, 2007

A short walk in Ishi country

It was an overcast Sunday, and a bit cool. Perfect hiking weather. We drove to the Deer Creek Trail in the Ishi Wilderness Area. As the crow flies Ishi's homeland isn't that far from our house, but we can’t fly across Butte Creek Canyon. The trailhead is an hour and twenty minutes away by car. We have to drive down into the Sacramento Valley, skirt the city of Chico, and head up the Pacific slope on Route 32 towards Mount Lassen.

We parked at the steel bridge, crossed the road and followed the trail into the conifers and oaks. Spring seemed a bit tardy. The white alders along the creek were just starting to leaf out, and Indian warrior had just started to bloom.

It felt good to be in the woods. Though these same trees dominate the landscape elsewhere in northern California, mossy pinnacles and volcanic ledges lend a special feeling. To me they are the witnesses to the past, like Steinbeck's silent watchers of Big Sur. The tragedy of Ishi's personal story makes the past tangible here. Perhaps he and his clan sought shelter under these very rocks.

Once he surrendered to captivity however, Ishi had no interest in visiting his old haunts. Perhaps there were too many spirits and sad memories, but Professor Kroeber finally talked him into it, and the famous anthropologist and his colleagues had the opportunity to see Ishi hunt and fish in his element. There's a picture of a smiling Ishi dog-paddling one of Deer Creek's dark pools. We passed three deep pools that could have been the place.

Ishi often made reference to Coyote, and the anthropologists decided it was time to record the Yana mythology. They prepared themselves for a couple hours of recording, but Coyote's story was an epic saga, and Ishi really got into it. He couldn’t stop after two hours. The story went on and on for several days. The anthropologists were amazed at the many threads. I find the underestimation of UC's distinguished anthropologists very amusing.

Native American's have had a legendary knack for unexpected statements of penetrating eloquence, which brings to mind a story that the late Bart O'Gara told me in Missoula, Montana in the early 1980s. A young well-intentioned man of his acquaintance, much inspired by his own daily work as a game warden, got it into his head that the Lakota could restore their pride and find employment as wildlife biologists. He conceived of a program to train the young men as game wardens. A meeting of the tribal elders was held, and he made his pitch, which played rather heavily on the theme of the Lakota's inherent skills and natural superiority as hunters and trackers. When the sermon ended the elders were asked for their views, and the senior spokesman summoned that unexpected eloquence (I paraphrase from memory): "You know, this is what they tell us, that we were great hunters and did all those things. (pause) Maybe it is true. (another pause) But maybe it is just bullshit."

Nowadays California's native people own casinos and donate generously to our communities. There's a poetic justice in their adoption of our values, but I don't have an iota of interest in casinos. Ishi's spirit world has far more to offer me. So give me Ishi's mountains and rivers. Coyote and the cast of characters are still here, the ones I want to capture with camera traps.

Monday, April 2, 2007

More aerial dogfights

The aerial dog-fights of spring are still going on, and I finally got a picture of it. Rufous hummer, the aggressor here, pilots the smaller aircraft. He is a barnstorming stunt pilot. The sight of him whizzing about has the Anna's hummers on guard.

At the feeder he just points his nose-cone and intruders back off.

For a long time the flight of hummingbirds remained a mystery, but high-speed stroboscopic photography opened the door to understanding. We have Harold Edgerton (1903-1990) to thank for that. He invented the electronic flash and stroboscope. Doc Edgerton was a small town boy from Nebraska whose interest in photography and electronics led to a distinguished career at MIT. He captured stunning images of things the human eye would never otherwise see. Why Edgerton never tackled the question of hummingbird flight will remain a mystery. He certainly wasn't opposed to applying the technology to biological problems, as he did with Jacques Cousteau. Anyway, his invention held the key to seeing the magical wings at work.

It was a contemporary of Edgerton's, the CEO of the Du Pont Company, Crawford H. Greenewalt (1902-1993) who decided to study hummingbird flight with the use of stroboscopic photography. How refreshing to learn of a CEO who was not only willing to support science, but became personally involved. With a hummingbird trapper, camera equipment, and wind tunnel in tow, he photographed 55 species of hummingbirds from the US to Brazil. The output, a coffee-table book titled simply "Hummingbirds" was published in 1960. It was a labor of love. Nowadays, original editions command as much as $225.

Greenewalt's treatment of hummingbird biology wasn't superficial, but he wanted to translate science for the lay audience. A reviewer's copy of the book landed on the desk of the late ornithologist Alden Miller at UC Berkeley. (His father, Loye Miller was among the first to suggest that the Anna hummingbird's dive-noise resulted from the braking sound produced by the outer tail feathers.)

But Greenewalt failed to include a bibliography in his book. Miller commented: "I think that neither the author nor the American Museum should feel compelled to try so hard to meet the untrained reader as to fail to provide avenue of access to source articles should his interest become aroused. He should not be so assiduously walled off from the pursuit of scholarship." (The codger couldn’t agree more.)

More recently a team of scientists led by Doug Warrick made a breakthrough in the aerodynamics of hummingbird flight. Previous researchers believed that hummingbirds fly more like insects--that is, the wings' downstrokes and upstrokes generated lift equally. Warrick and colleagues used a new method called digital particle imaging velocimetry (DPIV). Basically you put your hummer in a wind tunnel, atomize olive oil in the jetstream, and let the little guy do his thing. Then you use a pulsing laser and digital videography to measure the effects of the wing movements. They found that hummingbirds support three quarters of their airborne weight during the wings' downstroke, and only a quarter of it during the upstroke.

So, we are still learning about the flight of hummingbirds. As for the Anna's hummingbirds dive-noise, the late and great Luis Baptista and Margaret Matsui questioned the conventional wisdom after observing the behavior and recording the sounds. They submitted "that the dive noise. . . is mostly, if not entirely, vocal in origin".


Baptista, L.F. and M. Matsui. 1979. The source of the dive nosie of the Anna's hummingbird. Condor 81:87-89.

Greenewalt, C.H. 1960. Hummingbirds. American Museum of Natural History and Doubleday and Company, N.Y. 250 pp.

Miller, L.H. 1940. Sound produced in the nuptial dive of young Anna Hummingbirds. Condor 42:305-306.

Miller, A.H. 1960. Review of "Hummingbirds". Condor, 61:100. (http://elibrary.unm.edu/sora/Condor/issues/v063n01/index.php)

Warrick, D.R., B.W.Tobalske, D.R.Powers. 2005. The aerodynamics of hummingbird flight. Nature 453:1094-1096.