The incredible rightness of stinking

Three nights before the puma heeded the call of the canned rabbit, a gray fox visited the mossy rock. The initial temptation was probably the distressed voice in the tree, but fox found something on the rock far more alluring -- a brown smudge of goo -- commercial beaver scent. It's made from the beaver's castor glands and their contents. Four weeks earlier I had dabbed the moss with a half-teaspoon of the stuff.

Beavers scent-mark their mud mounds with castoreum. It's strange sweet smell is due to large amounts of phenolic compounds. Like other animal musks, it is also used as a fixative for perfumes. A manufacturer of tincture of castoreum advises men to use it when they want "to regain sexual vitality" or "to face the social context with the wild energy of the trapper". Sounds versatile.

Back to the fox…it arrived at 8:32 PM , and its tryst with the goo lasted five minutes. The camera photographed the episode about every 18 seconds.



When fox wasn't sliding its neck over the scent it sniffed with the rapt concentration dogs devote to stinky things ("Don’t bug me right now. Can't you see I'm busy?").



But something out there in the dark was distracting fox from the intimate ritual.



Fox's parting act was to leave a deposit…a fecal deposit. "I've been here. I 've absorbed the smell. Now I leave my smell." He had been eating manzanita berries (rather dry and mealy at this time of year).



I don’t believe the critical experiment has yet been performed on what advantage members of the dog family gain from anointing themselves with smelly things. One theory is that the foreign scent makes the animal smell interesting to its peers.

Whatever the function, when fox left it probably felt the incredible rightness of stinking.

Wet cat on a rainy night

I've had a camera trained on this mossy rock since December 6. Though I've used scent and sound lures to attract game, it’s not a very active place. I was going to pull it today, but I got a surprise when I checked the pictures.

This photo was taken 4 days ago (Feb 9) during the long overdue winter showers. Unfortunately, the wetting agent I used on the camera lens window didn’t prevent water drops, and I guess it's time to get serious about placing a couple of external flashes for better lighting. I mean, this could happen again. If the mossy rock is on the cat's beat, I can expect the next visit in 7 weeks (see "The owl and the pussy cats", December 2006).

What is it looking for? It's looking for the "canned rabbit". That’s a digital player that sounds like a distressed rabbit in a tin can. I hung it on an overhead limb on January 27. It plays for 5 seconds about every half-minute all-night-long.

My wife was with me the last time I checked the canned rabbit's batteries. When I switched it on for the test run she asked, "What in the world are you doing?".

"I gotta test it, don't I."

"Well, you don’t have to test it when I'm here." She insisted that we depart immediately before the place was crawling with mountain lions or bears.

That was February 3rd. Six days later big kitty heard the canned rabbit up in a live oak and posed on the mossy rock.

Woodrat tricks codger (continued)

Wood rat couldn’t cut the mustard when it came to climbing down a vertical quarter-inch cord. But could he walk across the same cord if it were horizontal? I pulled a quarter-inch cord taut like a tight rope, and repaired the vertical cord that he had almost chewed through. The next morning the vertical cord was dangling and the bait cup was gone. The pictures tell the rest of the story.



He had fed intermittently for a half hour, and cut the bait free in less than a half minute. I revised my thinking. Making the first cut beneath the food wasn’t so dumb after all. If he cut the rope above the bait it could drop into a thicket below, and that would mean a lot more work. Better to cut it free and haul it home in one set of actions.

There was no sign of the cap that held the peanut butter. He must have cached it in his nest for bedtime snacking. I repaired the set up, and the next night was a repeat performance.

Now that wood rat was a habitual visitor, I expected he would go to any length to reach the reward. So I replaced the 1/4" cord with a 1/8th" nylon cord. I figured a really good climber would hang-crawl along the string to reach the feeding station.



Wood rat would have no part of it. On the next two nights he visited the access route as many as 8 times a night, but would stop where the 1/4" line was knotted to the 1/8" line. There he would look longingly in the direction of the bait. It seemed that wood rat wouldn't walk the line if it was less than a quarter-inch thick.

So far, so good. But now I wondered . . . was wood rat capable of "chimney stemming", — that’s what rock climbers do when they brace themselves and "inchworm" between two parallel walls. I wired a 26" length of 2" PVC pipe, the chimney, between an overhead branch and the platform. The only way he could reach peanut-butter-land, I thought, was to go down the tube. I set one camera trap to monitor the tube entrance, and another to monitor the bait station below.

He visited the bait station for two nights, and I assumed that he was chimney stemming.



But a little knowledge can be dangerous. The picture of the hind-foot hooked over the twig showed that he can't rotate his ankles and cling like a squirrel. Therefore, I thought he was testing it in this picture. He couldn't possibly go down the outside of the tube head-first. He had to be going down inside the tube.

A simple test could prove it. I stuffed an old sock--yes it was clean--into the entrance of the tube, predicting that he would either pull it out and proceed down the tube as usual, or have to forego dining at the bait station.

When I looked at the pictures the next morning, I realized the rodent had tricked me.




He didn't remove the sock, but there he was on the platform eating the peanut butter. Damn! My design was flawed. I had allowed him two options--go up the post or come down the tube. Not good experimental design. My early assumption that he couldn't climb the 3/4" aluminum post had been wrong. Now I was wondering if he ever came down the tube at all--inside or outside.

So I removed the tube to see if he could climb the post.

Surprise! The next morning's pictures showed the rat on the platform.



He could have gotten there only by jumping, levitating, or shimmying up the post. There were no climbing action shots, but there was this picture of him on the verge of descending with a mouthful of peanut butter. I had the feeling I was finally getting closer to the truth.

If you think you can bear any more of this, stay tuned for the final episode.

Wood rat accepts the challenge

Okay class, today we're going to see how the scientific method can be used to explore an important and unanswered question: how well do dusky-footed wood rats climb?

The irrepressible mammalogist Jack Cranford reported that radio-collared wood rats spent 40% of their time above ground foraging in shrubs and trees, and the late E. H. Vestal described a worried wood rat leaping three and a half feet—a rather squirrel-like achievement. So, it's fair to ask: is Neotoma fuscipes a confident and acrobatic climber? Or a cautious climber? It was time to subject wood rat to some climbing trials and put the camera traps to good use.

Where to begin? Go to the literature! Linsdale and Tevis, in their book "The dusky-footed wood rat" reported a rat climbing a poison oak vine. Poison oak vines come in various thicknesses, but cutting them for experiments can have uncomfortable consequences. So my first question was: can wood rat climb a 3/4" manila rope?

I tied the rope to an overhead branch of oak, and moored the other end to a log on the ground. Only by climbing down or shimmying up could woodrat reach the peanut butter feeding station in the middle of the rope. I hoped for a picture of him clinging to the line like a mountaineer.



Wood rat accepted the rope-climbing challenge, and cleaned up the peanut butter the first night. In fact, he made several visits. I assumed that he descended the rope from the overhead branch. It seemed easier than surmounting the feeding platform. Whatever he did, he did it quickly, because there wasn't a single picture of him coming or going.

Time to "raise the bar". The next night I replaced the vertical rope with a 1/4" cotton clothesline. I also replaced the plywood platform with a bait cup strung on the cord.

No longer could he sit and dine.
He would have to feed while on the line.
Ahah! Two nights passed with nary an image.
Was the 1/4" line beyond his limits?

Or was woodrat digesting in the stomach of a fox or bobcat? It was too easy to discover his limitations, and I wondered whether I had somehow exposed him to danger. I mean, like...gee whiz...maybe he attracted a predator while scurrying about trying to reach the peanut butter.

Okay, let's make it easier for the guy. On night 4, I used the 3/4" rope to make a bridge. All he had to do was walk across the rope to the clothesline where the peanut butter was waiting.





And that's exactly what he did. The next morning's photos showed woodrat alive and well, and eating peanut butter like there was no tomorrow. I could only conclude that he was no match for his crazy ninja Malaysian relatives (see the previous blog, mates). Climbing the vertical clothesline (1/4") was beyond his ability. He seemed a little resentful tugging at the cap and chewing the line, but he wasn't clever enough to cut the cord above the bait. The unfinished meal was still there. I felt a little disappointed and smug at the same time. But all that was to change. Wood rat had some tricks up his sleeve. (Stay tuned for the next episode).



REFERENCES

Cranford, J.A. 1977. Home range and habitat utilization by Neotoma fuscipes as determined by radiotelemetry. Journal of Mammalogy 58(2):165-172.

Linsdale, J.M. and L.P.Tevis. 1951. The dusky-footed wood rat. University of California Press, Berkeley.

Vestal, E.H. 1938. Biotic relations of the wood rat in the Berkeley Hills. Journal of Mammalogy 19:1-36.

Ninja rats of the Bumbun

A studly wood rat with an addiction to peanut butter lives about 50 yards from the house. For the past week I’ve put him through a series of climbing trials. But before I post that blog I want to share a deep secret—my fascination with the climbing ability of rats. It started the night of October 21, 1991 in peninsular Malaysia’s national park—Taman Negara.

We had decided to sleep 30 feet above the jungle in the "Bumbun" ("Boomboom" is close enough)—a wildlife observation blind. The elevated cabin was big enough to sleep 12 people, and rested solidly on massive posts. It looked like a titan gazing over a clearing in the jungle, where the park staff had created a salt lick to attract wildlife.

That morning at park headquarters we bought fried chicken and cheese sandwiches for the overnight outing. As the young lady of the kitchen staff handed us the bags she advised us to hang them from the strings on the Bumbun’s rafters.
"Huh?" I responded.
"Sometimes a rat will eat your lunch", she explained.
"Rat like fried chicken very much. Hang bag on string, they can’t get it. No problem", she giggled, "okay?".

When we climbed into the bumbun that afternoon we didn’t need a shower. A torrential downpour had taken care of that, so we changed into dry clothes, and prepared for a night of wildlife observation. The park had provided engaging reading material—a log for tourists to record their natural history observations.

Most of the entries were tales of red-eyed wayfarers defending their food bags against a determined army of rats. The rodents came in various sizes, but we learned they all had uncanny abilities to invade the bags of food. There was enough material there for a Ph. D. thesis and a Stephen King novel. I knew that peninsular Malaysia boasted of having at least 20 species of rats, and the log’s colorful descriptions assured us we would see at least a few of them up close and personal.

We ate our modest meal, carefully wrapped the remains for tomorrow’s breakfast, and hung our bags from the rafters. Then it was dark. I tape recorded night sounds, and periodically we saw movement at the salt lick, but the beam of our flashlights proved we were imagining things. When my wife and I climbed into our bunks, we promised to wake each other up should the rats make an appearance.

At 2:00 AM, asleep and enfolded in the moist warmth of the tropical night, I felt something on my foot. With one tremendous power-kick I tried to launch the little bugger into outer space.
"Do you know what you just did?" came my wife’s voice in the darkness.
"I got him, didn’t I?"
"No, you almost kicked me in the face. The rats are here, but I couldn’t wake you up."

And there they were in the beam of the flashlight—not the scrofulous imposters described in the log, but nimble fellows, gliding along the rafters with their russet coats, white bellies, and blueberry eyes. There were two species. One had a tail as long as the head and body. The other had a noticeably longer tail. But they were no ordinary rats. These rafter-runners were pumped up like ninjas. The smell of the cheese sandwiches and fried chicken was driving them crazy. Their speedy peregrinations seemed to be a race to see who would be first to triangulate the food by scent.

What we failed to notice was that one of them had already gotten into the food bag, which was vibrating with its frenzied feeding. I climbed down from the bunk and gave the bag a flat-handed smack. Waaaaah! Such reflexes and coordination! The nibbler literally shot up the string like a yo-yo. That's not something many rats can do. These guys were built for climbing.

The ninja rats were rash and reckless, and though we defended our lunch bag, it was impossible to fend off "Yo-yo" and his kin. It was their turf, and we were outnumbered. By 5:00 AM we were tired of the game, and the rats were full of chicken, cheese, and bread. It was time for bed, they had earned their keep, and I knew something I didn't know before--some rats are damn good climbers.

Hunting pumas with kindness

Dr. Rob Horwich of Gays Mills WI just responded to the previous mountain lion blog:

"I recently heard about that lion attack and another where a mother defended her 7-year-old against a cougar for an hour. I think California should institute the old cougar hunts with dogs (but in this case the "hunts" should be non-lethal). I think that would probably give the mountain lions some fear of humans. In Belize the mountain lions are described as "upstart", but they are smaller in Belize, and I am unaware of any attacks there. By the way, I recently heard about a huge pack of 53 squirrels bringing down a cougar, so once again nature establishes a balance."

Horwich’s "benign hunting" idea has merit. Use aversive conditioning to change the puma’s minds from ‘people are prey’ to ‘people are scary’. If the idea conjures images from Stanley Kubrick’s screenplay of Anthony Burgess’s "A Clock Work Orange", allow me to reassure you. We’re suggesting a kinder and gentler aversion therapy than that.

Here’s my take on it. First, consider an area where wildlife biologists deem people to be at high risk of attack by pumas. The hypothetical area has a known population of pumas, a low population of deer, and is frequently used by hikers, mountain bikers, and joggers, who occasionally report sightings of prowling pumas. Maybe harmless puma-human encounters have already taken place. In other words, the clock is ticking.

Responsible wildlife authorities would be scientifically prepared for the undertaking. They would have baseline information on puma-human encounters, and an index of puma abundance based on indirect census methods, such as counts of sign and camera trap records. Next, the wildlife biologists would stage mock hunts. Winter might be the best time. That’s when puma mothers teach their cubs to hunt. The hunters themselves would be professional wildlife biologists, and they would track the lions with hounds until treed. Have you ever seen a picture of a treed puma? Their body language tells it all. If you will excuse my anthropomorphism, they wear a look of terrible humiliation. After a few unpleasant encounters the sight and sound of people and dogs will give pumas what we Californians call "bad vibrations".

If the method works, pumas would avoid rather than stalk people. In any event, the field surveys would give quantitative measures of success or failure. In other words, if the cats avoid the area and puma sightings decline, we could consider the method successful.

Having worked for the government for many years, I know that bureaucrats usually do not cotton to really good hare-brained ideas. So I would anticipate two kinds of responses. The "argument of personal responsibility" would maintain that the hiker who is informed and cautious about pumas is a safer hiker.

Good bureaucrats also use more than one excuse. The coup de grace to the well-intentioned but misguided suggestion is the "argument of fiscal limitation". "Your suggestions, while interesting and of possible utility under specific circumstances, are not feasible for economic reasons." This is usually followed by a litany of statistics about the department’s enormous scope of responsibility, low staffing levels, and equally important competing needs. Your hair-brained idea is dead meat.

So, let "benign puma hunts" increase departmental revenues. It could be tastefully done. There would be no shortage of well-heeled Silicon Valley naturalists who would pay big-time to tree a puma and shoot it (with a camera). Hey, aren’t Apple’s latest operating systems named after the big cats? What are we waiting for? Thar's gold in them thar hills!

When a mountain lion attacks

My heartfelt sympathies to the Hamms, who fought off a mountain lion attack last week. The couple’s chilling description of the ordeal and their determined defense has inspired a great deal of interest and compassion, not to mention lame rhetoric and political commentary. Fortunately, Mr. Hamm is on the mend, after a turn for the worse due to infection. The Hamms have always enjoyed hiking in wild places, and I hope they won’t give it up after this experience. But if they do, so be it. You can’t really blame them.

California’s wildlife advocates invoke changing demography to explain the increased frequency of mountain lion attacks. It stands to reason. The state’s landscape looked a lot different in 1849 when a very sick wagon train captain named J. Goldsborough Bruff (1804 - 1889) decided to call it quits. He dropped out somewhere in Lassen County, wintered in a shanty, and kept a diary. His account gives perspective on what it was like when wildlife outnumbered people. Bruff ran out of food, but the native Yahi offered no succor. Nasty encounters with a steady stream of unsavory fortune seekers had already taught them to keep a low profile. He resorted to scavenging the carcasses of abandoned oxen and big game killed by wolves, grizzly bears, and mountain lions. The predators didn’t leave much meat, but he lavished praise on the choice broth he concocted from the boiled bones. No doubt wild game outnumbered people one hundred and fifty years ago. There was even enough carrion around to support a population of condors. Bruff knew—he shot one.

Long gone are the wolves and ‘grizz’, but the California Department of Fish & Game estimates we share our state now with as many as 6000 mountain lions. And the census takers tell us the golden state has 35 million people. (It’s easier to count people.) The place is changing in other ways. Most of the quaint towns of the coast range, foothills, and Sierra Nevada have given way to burgeoning suburban communities. San Francisco’s bay area baby boomers have migrated to the foothills and beyond into the Sierra Nevada, so a lot of people now live much closer to nature. Mountain lions and other predators must see or encounter a lot more people than in the past.

There’s a clear and present danger when large predators encounter people more often than their normal prey, and this might have been the case with the lion that mauled Mr. Hamm. Cal Fish & Game officials killed a pair of mountain lions near the site of the mauling, and identified the female as Hamm’s attacker. Mountain lions are solitary, which means the female was with her offspring or was having a fling. Either way, two cats get half as much to eat when they make a kill. To eat normally they have to kill more often.

When something like this happens, I get a lot of free advice from family and friends. Normally they view my camera-trapping sorties into the woods as harmless eccentricity. In the wake of near tragedy they behave like officials of the Occupational Health and Safety Administration (OSHA). I can’t defend my outings with the old arguments about probability—"I’m telling you the odds are better of getting hit by lightening than killed by a puma."

But I don’t really want to tempt fate, so I have to consider the expert advice. Don’t go into the woods alone. Carry a big stick. Don’t run when you see a puma. Make your self look big. Etc. Neighbor Richard advises me to take a sidearm, preferably a double action .38 caliber. Professor Wolfgang Schleidt, my grad school mentor in ethology tells me to carry a black umbrella. (Indeed a 19th century German explorer crossed Africa unscathed by flashing open his umbrella at all threatening beasts). And why not don a crash helmet and neck brace? Pumas invariably attack the head and neck.

I am trying to heed the advice of family and friends. My daughter bought me an air horn, and my cautious wife advised me to take the walkie-talkie on my outings—not that anyone could ever find me should I send an SOS.

So a few days ago it was again time to check the trap line.

"Sweetie, how about a hike down in the canyon this afternoon? Two is safer than one, right?"

"You walk too fast. And with my luck the puma would attack me, the slow weak one. Take the walkie-talkie and the air horn Lauren gave you".

I arm myself with a big stick, the walkie-talkie and the air horn. I leave the other walkie talkie in the kitchen. With my knapsack on my back, I head down into the barranca—"valderee, valderah, valderee, valderah ha ha ha ha ha….",

Safely at destination, I drop my knapsack, and pull out the walkie-talkie to report to home base.

"Okay sweetie (puff puff), I’m here at set 21. . . the mossy rock--where I got the puma pictures. . . Do you read me?"

The walkie-talkie goes "Blurp", and there is silence.

"Okay sweetie", I repeat, "I’m here. . . are you there?"

Another blurp, another silence.

Back at the house, I query my beloved whether she heard me calling, and she answers, "No, I was in the computer room.

"Well, what if a puma had attacked me."

"If the puma attacks call when I’m in the kitchen."

My wife is a practical woman.