Walking the plank

When we set the cams in Marin County it was raining and I was wet. I would have preferred a more natural crossing over the creek, but the animals didn't mind.

Five species crossed the creek here, but not all of them walked the plank.

The first animal to do so was an immature-looking bobcat. It might have crouched when the red-eye flashes starting to blink. That was at 5:47 AM.

Thirteen days later a larger bobcat crossed shortly after midnight, and shut its eyes when the camera flashed.



I believe this was the same animal sitting on the plank at 3AM three days later. It was probably waiting for something edible to come trundling down the creek bed, which was dry.



We got 6 pictures of bobcats on the bridge or the trail leading to it.

Newtsville, CA

Rich and I collected memory sticks and changed batteries on Sunday at our Marin County site.

It was threatening to rain.

The newts were out and about, and you really have to watch your step.

Not only is it cruel to step on a newt, it is very unpopular to do so in Marin County.

Some were moving across the trails, others were poised like bird dogs.

They were all looking for action, even when there was no need to look any further.

This is, like, very Californian.

Animal psychology for camera trappers – Part 3

The late Stanley Young (1889-1969) trapped predators for the Bureau of Biological Survey and documented the demise of Colorado’s loner wolves.

The loners were habitual cattle killers, often trap-maimed and sometimes idiosyncratic animals with monikers like Old Two Toes and Club Foot.

The Custer wolf kept company with coyotes. Killer was coyotecidal, and Whitey had a penchant for bobbing the tails of cattle.

They were notorious at eluding federal trappers and postponing the fateful grip of the Newhouse No. 4 ½ -- a forged steel double long-spring, smooth-jaw trap with drag chain and grapple.

But eventually they erred, and the traps got them.

The longevity and killing rate of individual loners has recently been called into question.

The estimated ages of those loners whose skulls reside in museum collections are too young to account for the lifetime kills attributed to them. It’s more likely that several animals including dogs and wolf-dog hybrids contributed to the record.

But no one can deny the loners’ uncanny ability to detect the trappers’ painstaking efforts at disguise and deception. They could scent danger from minute traces and sidestepped hidden traps.

But if a trapped wolf twisted off part of its foot and escaped it wasn’t an experience it forgot. It was a powerfully painful learning experience, and relevant to discussions about the hurtful effects of camera traps.

So first let's talk about learning associated with pain.

It seems likely that, unlike children, loner wolves got the message after a single close call with fate. This is called single-trial learning

No matter how attractive the bait or lure, trap-wise loners fled trapping sites as soon as human scent was detected.

This type of operant conditioning is known simply as punishment.

Surviving a strychnine-laced bait had the same effect. We have all experienced conditioned food aversion – that long lasting food-specific loathing from food poisoning.

Conditioning can be specific to a given context. A trap-shy wolf might respond to human scent with conditioned avoidance when encountering a hidden trap, but not when encountering a flock of corralled sheep.

If the animal encounters the stimulus in a different context and doesn’t give the conditioned response, it is said to discriminate between situations.

The loners seemed to recognize the danger-laden stimulus of human scent in different contexts, and thus showed stimulus generalization. You can call this survival instinct.

Let’s compare these forms of punishment with the alleged “hurt” caused by camera traps.

Encountering a camera trap for the first time can be a surprising or unexpected experience for an animal. It may also be an alarming experience, but most of the time cameras do not evoke strong fearful responses, and initial vigilance quickly wanes.

Animals habituate to trail cameras because fear is not reinforced with painful stimuli. A repeating electronic flash may be ignored or investigated, but isn’t shunned.

All circumstantial evidence indicates that habituation is the prevailing response of wildlife to cameras left in the woods.

References
Gipson, P. S., W. B. Ballard, and R. M. Nowak. 1998. Famous North American wolves and the credibility of early wildlife literature. Widllife Society Bulletin, 26(4):808-816.

Young, S.P. 1970. The last of the loners. The MacMillan Company, New York.

Animal psychology for camera trappers – Part 2

Mammals and birds quickly learn to associate related stimuli or events.  Associative learning includes classical (or Pavlovian) conditioning and operant conditioning, as well as simpler forms of learning, such as habituation.

Camera-trap an area over time and there is a good chance your subjects will make an association between the camera and the olfactory and visual stimuli you leave behind.  

If you thought your camera trapping shenanigans in the woods were unnoticed, guess again. Chances are local wildlife knows the camera is there, and they are not afraid of it.

You will fool them more often if you set your cams in new areas where the residents have never encountered you and your equipment.  

The regulars who appear in your pictures may not know who or what you are, but in their universe or Umwelt you are a distinct blend of stimuli.

Why? Because you smell, and so does your camera, which also flashes and makes sounds.  

Whenever you venture into the field, you inadvertently scent mark your path and equipment.  

Unless you take extreme measures. Then you can reduce your scent by washing with unscented soap, wearing clean clothes, and masking your scent.

The best way to mask scent is to thrash your body like a Finlander in the sauna. No need to strip down or surround yourself with svelte blonds, just beat yourself with aromatic plants like bay or sage until you smell like trampled plants.  

The new carbon-impregnated clothes on the market may help to absorb some of your smells before they give you away.

Or you can spray yourself with Stumpy’s root juice.

But generally speaking, odor prophylaxis can be rather tedious, and scent-cleansing rituals will not render you smell-anonymous.

If you use scent lures or bait, like road kill, you reward the animal to tolerate the proximity of the camera.

Everything about the scent lure reaction -- from intensive sniffing, to slobbering, rubbing  and rolling in the scent, as well as evacuating the bladder and bowel -- indicates they find it highly compelling and meaningful.

The camera becomes an accessory to pleasure. 

I have a hunch – let’s call it a hypothesis -- that when resident animals cross your scent trail they may search for your camera, because food and scent have repeatedly reinforced tracking your scent trail.

Your scent is a cue to seek the reward of “good smells and eats”.

I believe this is more likely in species have relatively small home ranges, because the probability of camera encounters is relatively high.  We’re talking here about wood rats, gray foxes, skunks, opossums, and racooons.

On the other hand, baits and scents may be less habit forming in far-ranging species like mountain lions, wolverines, fishers, bobcats, and coyotes.

It takes more time for them to make their rounds in their larger home ranges. Positive reinforcement will not occur until the animals have been repeatedly rewarded. 

In support of this idea I would point to the tigers in Nepal’s Chitawan National Park. 

Though they killed tethered buffaloes at a bait site near Tiger Tops Jungle Lodge, radio-tracking showed that they ranged as far and wide as other tigers in adjacent home ranges. In other words, they maintained their usual beat in search of prey. Some cats however became habitual bait visitors.

Okay, I've slipped from animal psychology to arm chair theorizing. Now someone needs to collect the data.

Citizen camera trappers make the news

Citizen wildlife monitors in Washington state were busy this summer camera trapping in Washington’s Central and North Cascades.

Conservation Northwest, the I-90 Wildlife Bridges Coalition, and the Wilderness Awareness School sponsor the Cascades Citizen Wildlife Monitoring Project.

The project’s goal is “to engage and educate citizens” as wildlife investigators along a 15-mile-segment of the I-90 Snoqualmie Pass highway.

They set their 43 camera traps in the woods, and were rewarded with thousands of images, including some rarities like gray wolf and Canada lynx.

Lynx were previously more widespread in Washington, but it seems that breeding wolves were completely unexpected.

Neat.

Read about it here, and be sure to check out the links.

Among the commenters are farsighted individuals who don't want taxpayer money wasted on wildlife corridors because elk-wildlife collisions don't affect them. (Aren't they the ones who holler the loudest when an elk totals their car?)

Thanks to Professor Tenaza for the link. (Hey, Rich when are we gonna check the cams in Marin?)

Animal Psychology for Camera Trappers-Part 1

[A raised forefoot while immobile and staring often indicates uncertainty. This full-frame photo shows an alert young squirrel fixating the camera with hesitation. In the next frame it resumed eating sunflower seeds.]

Many animals are cautious or fearful of unfamiliar objects or situations. This healthy response to the unknown is called neophobia or “fear of the new”.  

I believe that neophobia was the reason my first camera trap pictures of gray fox were in the distance or half out of the frame. After a few weeks the animal(s) approached more closely, and finally became bold enough to examine the camera at close range. 

 

[A jackrabbit assumes a startled stance in reaction to the camera trap. The widely spaced rear feet indicates it is prepared to bolt.]

If there is bait near the camera you might read ambivalence in a neophobic animal’s body language. 

The attraction to the food is strong, but so is the hesitation to approach the strange object near by. The animal may stare at the camera, or stretch its body and creep forward as though it wants to approach and back off at the same time.

 

Or it may approach and sniff toward the camera, then circle and test the air from a different direction. These are manifestations of approach-avoidance conflict.

Caution wanes quickly when repeated exposure to a strange object proves harmless. Since there are neither positive nor negative consequences, the animal habituates to the stimulus.  

Habituation is why we don’t often see neophobic or avoidance–conflict reactions in camera trap photos. 

Also, habituation usually defeats the clever tinkerer who cooks up various repellents for garbage-can bears and bird-feeder squirrels. Fearful reactions wane, unless the repellent is painful or extremely disturbing . The animals habituate. 

[A jackrabbit in a normal resting stance in its form (nest).  The animal habituated to the camera which was staked closer to the nest on three successive nights while the animal was absent. The camera recorded its daily cycle of rest, grooming, and defecation for a week without apparent disturbance.]

Denning bears revisited (in more detail)

[red momma pulling grass toward den entrance]

Brian sent me a CD of all 213 photos taken of Red Momma and the two cubs (black and pale cinnamon), and I just compiled the data.

The three bears were active at the den for three days (Nov 4 – 6), and then retired inside (Nov 7), where I presume they are napping now.

November 4th and 6th were workdays.

On the 4th they first appeared at 2:54 in the afternoon. They went in and out of the den several times until 3:06. Then the black cub and mother pulled bundles of grass into the den for 6 minutes, and disappeared.

They were back 5 hours later. Black cub went into the den, and mother resumed dragging grass to the den. After getting it down the hole she rested in the entrance for an hour.

Shortly after midnight, the pale cub -- who had contributed nothing to building the nest -- left the den.

[the slacker, after its nap]

Mom periodically lounged in the entrance looking out into the starlit night until 5:00AM.

[starry eyes and bear thoughts]

She wasn’t photographed again until 11 o’clock the next night. There was no action during the day.

The next night was the same – mom lounged on and off in the entrance, and all three were absent most of the day.

They started nest building again on the 6th around 3:15PM, and work ended just before 6 o’clock.

[the pale slacker tries to back down into the den with mother in the way -- she didn't yield]

The camera recorded an ear or a paw moving in the den entrance 12 times during the next 24 hours.

[one leg up in the den]

Then Brian pulled the memory stick, and replaced it with a new one. We're not expecting much activity at the site for a few months.

In summary, the bears started nest building shortly after they arrived at the den, worked late in the afternoon, and were not seen in daylight before that. At night the mother seems to have alternated between dozing and star-gazed in the den entrance.

The pale cub seems to be a slacker. Not a single frame showed it pulling grass.

Any opinions as to what sex it might be?