About Me

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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.

Monday, March 31, 2008

A Jonah log

At last, I found what I've been looking for -- a Jonah log, a log for camera trapping from within. It's a fallen snag with a cavity about 12 inches wide and 6 feet long. No need for chain sawing. There's a large opening big enough for the camera trap, and a small opening to create a draft over the bait -- in this case, smoked herring. True, it's a bit far from home here in northern Virginia, but good Jonah logs are hard to find.

I hope the county park authorities don't mind some cosmetic adjustments. The cavity was a basin, a nasty microhabitat for disease vectors, and it seriously needed drainage. Plus, I don't need any surprises like finding a camera floating in punk water.

Then I juryrigged a camera mount (not many supplies here at my daughter and son-in-law's).

The walk test was impossible. I couldn't see if the sensor was detecting my hand, so I recruited the redhead. While she looked for the flash in the big opening I imitated a vet giving a rectal exam to a cow.

I am not promising anything from this Jonah log. There are just a few days left before we head home, but until then I'll be checking it daily.

Monday, March 24, 2008

Camera Trapping Workshop : schedule (draft)

Here's a draft schedule of topics and activities for enrollees and prospective takers of my camera trapping workshop at SF State University's Sierra Nevada Field Campus.

Sunday, July 20:
arrival and check-in.
After dinner:
introductions, goals, program for the week.

Monday, July 21:
Activity: camera trapping plan (what are we after and where do we look?); reconnaissance and deployment of cams.

Topics covered:
camera trap sets (ground versus arboreal)
camera attachment (trees versus posts, telescoping poles, bungies, cables, special attachments)
camera security (people and bears)
PIR sensors (strengths and weaknesses, compensations)
GPSing locations

of today's activities and topics
demonstration of GPS and topographic map downloading (aids to finding your cameras)

Tuesday, July 22:
(1) collect early morning cams; re-bait or re-set
(2) mobbing experiment (use of a raptor model to compare camera traps with hand-held cameras)
(3) predator caller demonstration

Topics covered:
(1) what camera traps can and can't do
(2) use of scent and sound lures
(3) anticipating behavior at the set and pre-visualizing pictures

(1) Collect pre-set cam B (hike); return and download photos
(2) owl calling (after discussion when it's dark)

(1) keeping records (to do it or not to do it?);
(2) camera trapping databases (inventory of set locations, spreadsheet of camera trapping results); photo index files;
(3) digital photo processing
(4) continued discussion of today's topics

Wednesday, July 23:
(1) collect early morning cams; re-bait or re-set;

Topics covered:
(1) camera trapping kits
(2) survival and safety in the wilderness

(2) collect pre-set cam C (hike); return and download photos

(1) batteries (alkalines vs. rechargeables)
(2) ecology and camera trapping (home range size and trophic relations; habitats and species).

Thursday, July 24:

(1) collect cams.

Topics covered:
(1) night-time photography (flash versus IR; supplemental external flash); fill flash

Collect pre-set cam D (hike); return and download photos.

(1) Topics of choice
(2) (activity) copy photos to CDs for participants

Friday, July 25:
(1) collect cams and pack
(2) evaluation

Saturday, March 22, 2008

Camera Trapping Workshop : mammal species list

Here's a list of some mammals for enrollees and prospective takers of my camera trapping workshop at SF State University's Sierra Nevada Field Campus. These species, from rare to common, are known to occur in the area. I didn't include the moles for obvious reasons (and gophers are almost as hard to photograph). Jim Steele, the station director says he is almost certain he saw a wolverine up there a few years ago.

We'll try to camera trap as many species as possible using two approaches. First, 3-4 weeks before the workshop I'll set 4 cams. That will give us about 100 camera-trap-days of effort, and we'll collect one cam per day during the workshop. Second, we'll use the other cameras to target specific species or groups of species. We'll make camera sets in specific habitats and microhabitats and check those daily too. I'll post a preliminary workshop schedule in a few days.

If you are interested in the topographic maps for the area the quads are: Gold Lake, Clio, Sierra City, and Haypress Valley. I have them on my laptop, but I'll also buy a set of hard copies.

Here are some references if you want to start researching any species of particular interest.

Mammalian Species" These excellent technical summaries published by the American Society of Mammalogists are downloadable as pdf files.

Verts, B.J. and L. Carraway. 1998. Land mammals of Oregon. University of California Press. Another excellent reference that also covers most of the California species.

Wilson, D.E. ad S Ruff. 1999. The Smithsonian Book of North American Mammals. Smithsonian Insititution Press, Washington DC. A comprehensive and outstanding treatment of all mammals in North America.

Ingles, L.G. 1965. Mammals of the Pacific States: California, Oregon, and Washington. Stanford University Press, Palo Alto. A bit out of date, but still a very useful reference.


Virginia opossum (Didelphis virginiana)


Coyote (Canis latrans)
Red fox (Vulpes fulva)
Bobcat (Lynx rufus)
Mountain lion (Felis concolor)
Black bear (Ursus americanus)
Marten (Martes americana)
Fisher (Martes pennanti)
Wolverine (Gulo luscus)
Badger (Taxidea taxus)
Long-tailed weasel (Mustela frenata)
Short-tailed weasel (Mustela erminea)
River otter (Lutra canadensis)
Striped skunk (Mephitus mephitus)
Spotted skunk (Spilogale gracilis)


Water shrew (Sorex palustris)
Marsh shrew (Sorex bendirei)
Vagrant shrew (Sorex vagrans)
Dusky shrew (Sorex obscurus)


Porcupine (Erethizon dorsatum)
Mountain beaver (Aplodontia rufa)
Beaver (Castor canadensis)
Douglas squirrel (Tamiasciurus douglasi)
Northern flying squirrel (Glaucomys sabrinus)
Golden-mantled ground squirrel (Spermophilus lateralus)
Yellow-bellied marmot (Marmota flaviventris)
Long-tailed meadow mouse (Microtus longicaudus)
Montane meadow mouse (Microtus montanus)
Deer mouse (Peromyscus maniculatus)
Brush mouse (Peromyscus boylei)
Pinyon mouse (Peromyscus truei)
Pacific jumping mouse (Zapus pacificus)
Red-bellied harvest mouse (Reithrodontomys raviventris)
Bushy-tailed woodrat (Neotoma cinerea)
Townsend's chipmunk (Tamias townsendi)
Long-eared chipmunk (Tamias quadrimaculatus)
Lodgepole chipmunk (Tamias speciosus)
Yellow pine chipmunk (Tamias amoenus)
Botta pocket gopher (Thomomys bottae)
Montane pocket gopher (Thomomys monticola)
Beechey ground squirrel (Spermophilus beecheyi sierrae)
Belding ground squirrel (Spermophilus beldingi)


Pika (Ochotona princeps)
Brsh rabbit (Sylvilagis bachmanni)
Snowshoe hare (Lepus americanus)


Black-tailed deer (Odocoileus hemionus columbianus)

Friday, March 21, 2008

You never know who's gonna show

Last September an Austrian camera trapper got a surprise. The gentleman, who monitors wildlife at his feeding station near the town of Rotenturm checked his camera and found images of some rather unexpected and unsavory visitors. If you read German the story is here.

The visitors were a couple of burglers who were seeking a quiet place to break open a stolen safe. In darkness they dragged the loot into a small clearing in the woods where our nature lover's infrared camera trap was waiting. The jokers were center stage and the camera recorded the crime together with images of their vehicle, including the license plate.

They were apprehended based on the camera trap evidence.

I am sure the camera trapper would have preferred publicity about images of non-human wildlife. But you never know who is going to show up in front of a camera trap.

Thanks to Wolfgang Schleidt for bringing this story to my attention.

Thursday, March 20, 2008

Fox in bright light

I reached for the unreachable star last week. I deployed the camera trap at a new set, but I also staked an external flash nearby. The inspiration to use an external flash came from Natasha Mhatre's recent flash photo of a short-nosed fruit bat. (Her blog is well worth visiting.)

Let's face it. When it comes to nocturnal flash photography side illumination looks a lot better than front-on lighting. The shadows give a better sense of contour.

It's been nearly a year since I used the external flash, but some of you may recall my previous exercises in external flash photography, like No more starry eyes and Showdown at Big Rock.

The problem is that the external flash eats up a pair of D cells in a week, and I haven't figured out a way to protect it with spikes should an irritable bear take issue with it -- which is very likely in these parts.

Reservations aside, I set the camera trap at this old snag, which snapped in the winter storms.

I set the camera's flash on minimal brightness for dim frontal lighting, but enough to trigger the brighter external flash which is on a slave unit.

As you can see, Br'er Fox made its usual appearance. At the top of the page it looks like it's witnessing an atomic test blast that just fried its eyeballs.

Here it's looking at the blast without the recommended sunglasses.

Obviously, the ASA on the flash was set too low.

Then Br'er Fox decided to get closer to the external flash by extending its neck. This is quite an achievement, but what I want you to notice in this picture is that the lighting is only from the camera. See? The stump lacks shadows.

I reset the ASA on the external flash to tone it down. Next week we'll see if it makes a difference.

Wednesday, March 19, 2008

Do you know where your dogs are?

If you don't, read this important message.

They are in a ravine, and it's wild down there. There's a lot of poison oak and things like big tawny cats.

It's not far from your house as the crow flies, but it's several hundred feet downhill and a quarter mile from the nearest road. Easy to get lost down there. Hard to find dead dogs.

But let's face it. If one of the dogs didn't come home you would hope for the best. You'd post handbills on the power poles, with your dog's description, picture, and name. And your telephone number. Then you'd wait for the call.

But the big cat in the ravine isn't picky. Dogs are fair game. If it can catch your pet, it's going to eat it.

You are right though, there's safety in numbers. Yes, two bold dogs could stave off an attack, especially if they see the big cat first and give full-throated chase.

But the big cat has the advantage down there. If only one dog comes home acting strangely, well, there's no need for the handbill.

So if I were you, good neighbor, I'd keep my dogs around the house. And I'd lock them up at night.

The big cats around here really like dog meat.

[BTW, the redhead finds preposterous irony in this post. "That's ridiculous, what are YOU doing down there?!"
Me: "I'm looking for owl pellets -- bwaaahahahaHaaaah!"]

Tuesday, March 18, 2008

Nature recharges my battery without fail

[Owling in '64]

At the instigation of Jochen at Bell Tower Birding, Owlman at Owlbox done tagged me.

Hey, what's happening?

Okay. The meme in the title of this post is a statement in six words about "my birder within". IOW, 6 words that describe me as a birder (kind of)! That was the assignment. I offer the archival photos only as supportive evidence because there is no mention of birds in my six words.

It could as easily have been "fur and feathers light my fire". (And that's about all that does these days -- LOL). Or "Raptors and Sousa stir my soul". Or "Birding is my kind of escapism". Or "I did my masters on shrikes". Yada, yada, yada . . . .

To keep this thing going I am tagging five other unsuspecting birdfriendly 'bloggas': Mr Smiley, Beverly, Terry, John, and Schmokin' Bill.

Here are the rules (copied from the original blogger who started this):

1. Write your own six word memoir
2. Post it on your blog and include a visual illustration if you’d like
3. Link to the person that tagged you in your post and to this original post if possible so we can track it as it travels across the blogosphere
4. Tag five more blogs with links
5. And don’t forget to leave a comment on the tagged blogs with an invitation to play!

If you all respond Jochen ought to be mighty pleased, and quaff a few extra beers at the corner Kneipe.

Now go do the right thang!

Sunday, March 16, 2008

Squirrel trials update #5

Last Monday we left for the bay area, but before leaving I stocked the owl box with sunflower seeds and made sure the camera trap was working.

Today I checked the camera to catch up.

After I put smooth plywood under the overhang the squirrels visited the box every day. They were stymied by these latest changes. They climbed about on the tree trunk and peered over the edge of the roof.

The deterrents didn't last long. On Tuesday, the first squirrel broke the sheet metal barrier. I regret not having a marked population of squirrels, and not recording the entry in movie mode. But somehow it reached the hole, and pulled itself in, as you can see for yourself.

The next day the same or another squirrel explored the box for 4 minutes and then made a left-handed side entry. Notice that the little bugger is gripping the upper edge of the roof with one hindfoot. The squirrel with the scratched nose did the same thing.

I am going to watch them for a few days to figure out their secret. Then it's back to the drawing board. Spring travel may force me to postpone further experiments until fall. The redhead just isn't very enthusiastic about watching squirrels and tending camera traps in my absense.

Friday, March 14, 2008

A curious cat

The four cameras we left in the Santa Cruz mountains a month ago took 244 pictures.

I expected at least a few coyote pictures, as there was plenty of scat to be found. We camouflaged only one of the cameras, so maybe wily coyote was camera shy. The rest of the cast was the usual assemblage of skunks, deer mice, woodrats, brush rabbits, and raccoons, as well as a varied thrush and a hermit thrush.

The camera hog was a young bobcat. Twenty+ pictures of it were on 3 of the 4 cameras. Most of the photos were taken at a small creek, really just a rivulet, where it seemed to be waiting to ambush thirsty birds in the morning. That was Reno's camera, and he was as happy about the photos as he was about finding some prime chantarelle mushrooms, which he generously shared with us. Good man!

I say 'young bobcat' because you can see that it still has to catch up with the growth of its ears, and obviously hasn't reached its fighting weight.

It made several skulking passes by my camera which was hidden under some coyote bush on a grassy hillside. I suspect it was the castoreum that attracted it.

The tear in its left ear told us it was the same curious cat. It had no qualms about facing the camera.

Sunday, March 9, 2008

Squirrel trials update # 4

Since the last update I extended the roof to 6 inches. I thought the wonder-rodent couldn't do the yogic stretch to reach the hole. When squirrel encountered the modification it looked over the edge, and didn't even try. It snaked around the corner from the side of the roof where the overhang is only 2.5".

Fair enough. I decided to add 5" vertical barriers to the sides.

This seemed to make it even easier. Now the squirrel could oppose the grip of its hindlegs at 90 degrees, and in one swell foop it did the yogic stretch to reach the hole.

Exiting the box is also a cinch. Though the redwood is smooth, the joints on the corners and sides offer the squirrel more than adequate purchase.

It was time to raise the bar, as they say, which in this case meant enlisting Richard's help again. We covered the box with galvanized metal flashing.

You are looking up at the one area that isn't flashed -- the underside of the overhanging roof.

By 11:00 the next morning the remote alarm inside the box had not sounded, and I was starting to think that maybe, just maybe, I had circumvented wonder-rodent.

"Guess, who hasn't gotten into the box today?" I asked the redhead rather smugly. (Her response, "Who?" was a polite admission that she wasn't really listening, a common pattern in the conversation of old couples and Seinfeld characters.)

Ten minutes later the alarm blasted in its irritating way.

A couple hours later I was gazing out the window and finishing a cup of coffee in quiet postprandial reflection, when the squirrel made a second appearance.

It climbed all around the box on the bark of the tree, mounted the roof, and looked over the edge at the hole. Then it rapidly scratched the metal roof as if trying to dig through. After a thoughtful pause, it went back to edge, leaned over the side, and crawled upside down on the exposed woodwork and entered the hole. It was just like a gecko.

This charged me with determination to do it one better. When the squirrel finished its repast 20 minutes later, I removed the roof and took it to the garage. Fifteen minutes later the undersurface of the roof was one smooth piece of plywood.

Stay tuned.

Friday, March 7, 2008

When a snag is not a home

I eyed this black oak with growing interest for two years. Those two knot holes, about 30 feet up, looked like they were made for owls.

Three weeks ago I got around to staking it out with a camera trap. I lashed the telescoping pole to a fir sapling, and raised the camera to the cavities.

Looks can be deceiving. I didn't even get a picture of a squirrel.

It looks as though the upper hole collects water which trickels into the lower cavity where it overflows. Somehow I failed to notice this.

No self respecting squirrel or owl would have anything to do with such a shabby place. Which reminds me, I have to repair the roof this summer.

Wednesday, March 5, 2008

Camera trapping grad student strikes gold

This is tremendous!

A graduate student studying carnivore ecology with the use of camera traps has photographed a wolverine in the Sierra Nevada. Read about it here.

This is about 40 miles south of where we'll be camera trapping this summer during the camera trapping workshop. (Who knows where I can get some wolverine scent?)

What a tremendous find!

Thanks to Nigel Rothfels (Wisconsin), Jim Steele (San Francisco), and Richard Lair (Thailand) for cluing the codger in.

Monday, March 3, 2008

Another mountain lion, again

This mountain lion wasn't cooperative. The fox and bobcat at least climbed up on the rock, and other mountain lions I have photographed have done the same on other rocks. But not this time.

I had 3 cameras out this last week, and two out of three had mountain lion pictures. This cat spent nearly 4 minutes at the site, but I got only 5 pictures. The camera was cabled to a crooked bay sapling and pointed up a bit too much -- not ideally aimed for a cat standing in front of the rock. (I corrected that today).

I used artificial civetone as a scent lure, and I imagine that's what the cat is licking. It came at 5:17 PM the day after I visited the set and put out the lure.

A close examination of the ears shows a notch in the right ear. That tells me that this cat is not Big Mama reported here a few weeks ago.

The other camera photographed the distant cat moving away from the camera. Three out of four lion photos on this trail show the tail-end of the cat. It seems the cat goes up the canyon by this route but returns by a different one.

As a aside, I have found two nests of band-tailed pigeons in this ravine. They are about 50' up in a black oak and a Douglas fir.

Sunday, March 2, 2008

Squirrel trials update #3

This is a progress report. We haven't yet solved the squirrel-in-the-owl-box-problem. But I believe we are getting closer.

The squirrels aren't early birds. Usually I hear the alarm between 9:00 and 10:00 AM and dash to the window to see what's going on. By then the squirrel is in the owl box. The regulars seem to be young of last year, perhaps siblings.

Since my last report they visited and fed in the open-topped box for a week. Then I put the roof back on, and they had to get past the overhang of 2.5".

As expected, there was no contest. They just hang over the front and enter.

After a week of regular morning visits I extended the length of the overhand from 2.5" to 6.75". Again, they didn't miss a beat. Their rotational ankles make it easy to cling to the front edge of the box and reach the entrance.

This afternoon I extended the roof to 9". The squirrels will have to span 11" to reach the hole from the front edge of the roof.

I expect they'll start coming in from the side, where the straight line distance to the hole is 6.75".

I just hope they don't lose their appetite for sunflower seeds, so we can finish the trials in the next two weeks.

Oh yes, something else is going on, too. Yesterday's squirrel had a bloody patch of skin on one side of its face, and this morning another squirrel showed up with a bloody snout. Has mom become a pre-partum crankinpuss, and is she kicking butt when last year's litter shows up in the nest? I wonder.