The Goose Pen

A goose pen with a circumference of 38 feet
can hold a lot of geese or sleep several loggers.

If you have seen one redwood you have NOT seen them all.

This old veteran was hidden in the brush and almost escaped our notice.

Standing 20 feet high, with a dbh (diameter at breast height) of 12 feet, it was one impressive stump and deserved thorough exploration.

I climbed down through a rent into the cavity 4 feet below the ground.

Several passages of differing size led to the outside through the charred walls, and internal recesses reached deeply into the roots.

This was one helluva place for a camera trap; so we climbed through the slash back to the truck and returned with the gear.

Then it started to rain.

The stump was not much of an umbrella; the camera case was soon wet, and the camera lens fogged immediately.

I tried drying it, but it was too dark to see what I was doing. I gave up and hoped for the best.

Before continuing our rounds, we interred some pieces of road killed squirrel into and under the old stump's walls.

Later that afternoon I told Lowell about the magnificent stump.

"You know what they call them up here?", he asked.

"Goose pens. The old timers used to pen up their geese in those stumps." 

The goose pen rewarded us with 107 photos of 9 species, and a success rate of 95%, which means there were few false triggers.

The deer mouse and wood rat of course were the first to show, but a hermit thrush appeared shortly after the alders dropped their leaves into the stump.

A Trowbridge shrew almost escaped my notice, but there it was, the voracious and fearsome midget mammal.

The brush rabbit's venture is a mystery. What was the attraction? It seemed a risky place considering the other visitors.

Of all the visitors, however, Fang the opossum spent the most time there (7 visits, 37 photos).

A bobcat paid three visits and left 11 images,

while a curious gray fox and a wet bear paused to examine the camera.

Though I like other images better, the shrew and the bear gave me the biggest thrill.

When I got home I realized I was missing my side cutting pliers.

You can see their blue handles under the bobcat's foot.

The blue plastic grips were all but missing when I recovered them.

There were rat nibble marks on the remaining traces of plastic, but the pliers still work.

30-year-old possum (picture)

It was 1978 in Front Royal, Virginia, when this fine possum took the bait and its own picture.

At the time, we were experimenting with a camera trap to take to Indonesia.

The Nikon FE had a motor drive, and the external electronic shutter release on the front of the camera body could be wired to a trigger.

We tried two kinds of triggers.

A waterproof pressure pad had to be buried and covered with dirt.

It was sensitive only to animals heavy enough to press together the internal contacts. This excluded dickey birds and mammals smaller than rats. Another disadvantage is that cold and icy weather made the plastic stiff and less responsive to heavier animals. All the same, often I have wished I could rig a Sony s600 to a pressure pad.

The other trigger was the Sti 2090 photoelectric cell. It was powered by a 9v battery and worked in tandem with a reflector. It triggered the camera whenever the beam was broken. Its disadvantage was that it was totally indiscriminate as to what broke the beam. On a windy day in November you could get 36 slides of autumn leaves in an hour. And oh yes, the trigger could be deactivated if a deer or cow bumped the reflector or the photoelectric cell.

But I have also longed for a simple photoelectric alternative to the PIR sensor on controller boards used with current trail cameras.

So here's a toast to an earlier era of camera trap technology.

Wire barbecued ribs to a stake at the edge of an alfalfa field. Tastefully place photoelectric cell and reflector over the ribs, but outside the camera's view.

When Br'er possum grabs the ribs -- camera takes picture.

You can see the edge of the reflector in the upper left margin. The photoelectric cell is out of sight.

Below you can see the pork ribs wired to a stake.

One last thing. The flash on this setup was a power-hungry battery eater.

Kids and camera traps

Question: How do you make it fun for kids to learn about ecology and  modern technology, and develop respect for nature?

Answer: Give them lessons in camera trapping.

That's what’s happening at Afton-Lakeland Elementary School near Minnesota's twin cities.

Dawn Tanner is developing a trail camera curriculum there for school kids.

Dawn is a University of Minnesota PhD candidate. Her baptism in wildlife research was in the Galapagos Islands and Malaysian Borneo.

She loved fieldwork, but decided that she wanted to get elementary school kids turned on to science, biodiversity, and conservation.

And how did that happen?

Well, she got an NSF fellowship that sent graduate students in ecology and conservation biology to Minnesota's metropolitan schools. Their mission there was to work with the teachers to improve science lessons and incorporate science more broadly into the school curriculum.

[Coyote at Cedar Creek Ecosystem Science Reserve]

Many Minnesota kids have formed positive attitudes about the environment by the time they reach the fifth grade.

"The kids' attitudes and their receptivity to environmentally responsible behavior is right on track. They score very high with respect to their attitudes about the environment, but they don't know what to do with it yet.”

"The problem is that city kids in particular are short on environmental experiences. The temptation to play with high tech toys in front of a TV screen is powerful. Enter trail cameras!"

Unlike many computer games that cultivate couch potatoes, trail cameras are an alternative "techie gadget" that is fun to use outdoors.

Trail cams can lure kids into the field, teach them how to monitor wildlife, and give them an exhilarating outdoor learning experience. They can even imbue them with a love of nature.

[Fisher at Cedar Creek Ecosystem Science Reserve]

At the moment, Dawn is testing the curriculum.

She and the kids have been using 8 trail cams at Afton State Park and Cedar Creek Ecosystem Science Reserve.

The word is out and teachers are interested.

“Quite a number of teachers have contacted me already because they've heard about the testing we're doing at Afton-Lakeland Elementary. They want to get involved right now." 

"I wish I could have the curriculum ready sooner. There’s a strong desire to teach with remote cameras and get kids out there doing biodiversity science.”

To date Dawn and the kids have photographed 12 species of mammals and birds.

"I'll monitor these two sites again this spring and add 2-3 new sites over the summer. We are aiming for about 140 trapnights per site".

"The folks at Cedar Creek Ecosystem Science Reserve have been so supportive to have me doing cameras there that they have volunteered to host a teacher training workshop in May, 2009."

"By summer we hope to have a web presence through the MN Project WILD website, so teachers can access data collected in protected areas around the state. This way they can compare monitoring results from their schoolyard with other areas."

The project has support from MN Project WILD, Gander Mountain, Stillwater Area School District, the Conservation Biology Program and the Bell Museum of Natural History (University of MN), MN DNR, and the MN Trappers Association.

If you are interested in the curriculum you can email Dawn at tann0042@umn.edu.

[Opossum at Afton-Lakeland Elementary School] 

Bulked-out bear digs for treasure

Rich just sent me the latest pics from the mountain, where the bulked-out individual seen above or one of his kin, dug a sizable hole in the woods searching for Emperor Norton's Treasure.

(To appreciate Emperor Norton it helps to be a San Franciscan or perhaps a Brit. The city was riddled with fox holes in the '50s when one of the newspapers sponsored a contest called . . . you got it! "Emperor Norton's treasure." )

This might have been Bruin's last aerobic exercise. He looks rather hangdog, obviously ready to retire for his winter's nap.

Other treasure seekers stopped to muse over his handiwork.





But the flicker couldn't care less about the bear's hole.



(Hey, remember the one about how to catch a polar bear? My daughters won't let me tell it to the g'kids. Unfortunately, by the time they're old enough to hear it, I'll be too damn old to remember it. )

California's possum diaspora

The Virginia opossum was one of my last camera trap visitors at Point Reyes National Seashore. As reported in my last possum post, this curious possum was also attracted to the electronic flash and gazed inscrutably at modern technology.

The Virginia opossum is one of California's recent mammalian immigrants, but the history of its colonization raises many questions.

What we know is that California's ancestral possums came from MacDonald County, Missouri and Jackson County, Tennessee, and probably other places as well, though no one knows for sure.

Those pioneer possums were tough. It would have been a grueling cage-rattling trip on the transcontinental railroad, but they could have toughed it out during the warm months. Sea travel would have taken more time, and seems less likely, but their sprawling "sea-legs" would have served them well.

At the turn of the last century the Golden State had much to offer its citizens in the way of wildlife, including grizzly bears, but her settlers from the South missed their possums. Possums may not be challenging quarry for the hunter, but memories of baked possum and sweet taters summoned mouthwatering cravings.

Early Californians kept penned possums for food, but they didn't keep them for long. I suspect the possum farmers soon grew tired of their chores, and decided it would be a lot easier to harvest wild possums. Maybe that's why one W.D. Watkins set five Missouri animals free about 3 miles south of San Jose. That was back in 1900. We don't know if they survived, but if they did, rest assured they went forth and procreated. In 1910 several more possums are said to have escaped from a San Jose jeweler and possum fancier. His seven possums came from Tennesee. Apparently possum owners in Los Angeles also had a hard time keeping their stock penned.

By 1913 one hundred opossums had been captured in the greater San Jose area (Santa Clara County), and by 1915 they had apparently made their way over the coast range into the San Lorenzo Valley in Santa Cruz county. This route would have led venturesome possums to the coast, and to easy routes north and south.

An attempt to introduce possums to mountainous Shasta county failed around 1932, but possums from San Jose spread into the San Joaquin Valley, circumnavigated San Francisco Bay, and thence colonized the northern coast range, the Sacramento Valley, and the northern foothills of the Sierra Nevada.

You are looking at a descendent of those hardy pioneer possums. The foggy windswept coastal scrub of Point Reyes is a far cry from the bottomlands of the south, but like the rest of us here, Br'er possum is quite at home.




References

Gardner, A.L. and M.E. Sunquist. 2003. Opossum, Didelphis virginiana. Pp 3-29 in Wild mammals of North America (G.A. Feldhamer, B.C. Thompson, and J.A. Chapman, eds.). The Johns Hopkins University Press, Baltimore.

Grinnell, J., J. Dixon, and J. Linsdale. 1937. Fur-bearing Mammals of California. University of California Press, Berkeley.

Ingles, L.G. 1954. mammals of California and its coastal waters. Stanford University Press, Stanford, California.

Lidicker, W.Z., Jr. 1991. Introduced mammals in California. Pp 263-271 in Biogeography of Mediterranean Invasions. (R.F. Groves and F. di Castri, eds.) Cambridge University Press, Cambridge, UK

http://www.geocities.com/royvandehoek/virginiaopossumanthology.htm

Memorable possums

You can say what you want about possums, but any animal that still resembles its Cretaceous ancestors is okay in my book.

Several possums have passed the cameras at Point Reyes National Seashore, and I finally got an acceptable picture (above). Most pictures have been partial views, and one possum actually reached up to examine the camera.



You expect curiosity from mammals with higher encephalization quotients, like bears and raccoons. But possums? Normally they show interest only food and other possums, and sometimes they get them confused. As possums go, this might have been a savant.

Since I am in a hurry, I'll devote this post to a few firsthand experiences, and save the wonders of possum biology for another time.

My first possum (many years ago) was a possum-in-the-headlights victim. It escaped the Firestone press with a severed spine, and looked intact on the outside, so a well-meaning zoology student delivered her to my lab at the University of Maryland (where I kept a large research collection of viverrids on the third floor of Sylvester Hall -- then the Zoology Building). I thought she might recover the use of her hindlegs, and welcomed the chance to learn about possums.

I learned that she had an insatiable appetite for dry dogfood, had an anal gland that produced a vile smelling green paste, and took occasional prolonged saliva baths with anything that didn't smell like food (which for a possum leaves a rather narrow spectrum of chemical stimuli). After licking an object into a lather, she shampooed her sides with the mixture. It was gross but fascinating.

The adaptive value of her other trick clearly had something to do with surplus killing. When offered several mice in succession she would dispatch them instantly, and stuff them into the back of her jaws with her delicate possum paws. Then she would take a long break, as if waiting for the next command. No doubt in nature she would trundle off and eat her prey. (I've never heard of possums caching food.)

A few years later when I was gainfully employed as a curator at the Brookfield Zoo in Chicago, the switchboard operator regularly transferred queries from the curious public. One of the more common queries was about possum reproduction. I remember one call in particular that went something like this:

Me: "Hello?"

Caller: "Yeah, me and dis guy are having an argument about how possums do it, and I stand to make some money on it."

Me: "Okay, tell me about it." (they were obviously in a bar.)

Caller: "He says that possums mate through the female's nose, and I says they do it the other way, like all animals. I say he's full of BLEEP."

Me: "Aha! Your friend is referring to the opossum's two-pronged penis and southern folklore . . .

So I told him that they "do it the other way", and explained that the female opossum has a duplex reproductive tract with two vaginas.

Caller: "Okay, now I want you to tell him exactly what you told me."

Several years later when we lived in rural Virginia, a rat sized possum ambled down the driveway in the headlights. I jumped out of the car and caught it by the tail. It had a certain charm, and our daughters were highly gruntled at the prospect of keeping it for a pet. But the redhead wasn't. I appealed to her sensitivity and promised that we'd let it go as soon as it got big enough to escape the big possums that are known to eat little possums.

Depending on the company, "Possie" was either a great conversation piece or the quickest way to send the neighbors home. With biologists, its appearance was an occasion for another drink, and reflective to bawdy commentary on the evolutionary success of such a homely creature. "You gotta love 'em, man!"

"Possie's" effect on nonbiologists was equally amusing. Furtive glances were followed by a brief period of polite indulgence, with perhaps a question about fleas and disease, and then the neighbors would thank you for the lovely evening.

A possum in the living room was a little trying for the redhead, who believed that her friends in town shouldn't know that we kept a possum in the house.

"Hey babe, this is VIRGINIA --the state animal is the VIRGINIA Opossum!" (Actually, the Commonwealth of Virginia has never owned up to this, though it has a state bat, a state dog, and a state fish! Disgraceful!)

More recently, a large male possum met his demise on the highway not far from our present house. It was just before Christmas and we were on our way home after eating out. I wanted to pull over to get it, but the family protested. I returned secretly in the night to rescue it from highway desecration.

The next day I placed it in a small opening in the chaparral. For three weeks it lay in peaceful repose before the camera trap. Skunks, gray foxes, and a bear visited, but no one touched it.



Apparently he didn't smell good enough for a mammal to eat. Finally the vultures came and finished him off.