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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.

Tuesday, December 9, 2008

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.


Robert J Miller said...


I recently added a link to your blog in our blog's sidebar: http://blog.TwoKnobbyTires.com/

Do you think our blog is worthy of being linked to from your blog?

Also, I am a volunteer naturalist and will be following your blog to learn tidbits for my future presentations.

Keep up the good work,
Rob Miller

Camera Trap Codger said...

Gotcha, Robert. And thanks.

cliff said...

The only testing I've done is with bears. In early spring and summer I know of several good bear locations where they feed to put on weight.

I know from past experience that bears do follow me from camera to camera and not randomly. To test this I found a good trail that forked in an opening where I set up a camera and only checked this one camera twice a week for a month and getting several different bears on every checking.

By now I knew the bears would know my scent and the test was to see if I could get them to follow me farther up the trail. I took a friend with me and gave him a camera, I told him to walk about 100 yards up one fork past my camera and set the camera aimed at the trail, walk a small circle in front of the camera and come straight back. I did the same on the other fork of the trail. We then walked back the way the way we came.

On every test, using different people, the bears would follow me and get their picture taken, never had a picture of a bear on the camera placed by a stranger. But if the same person came with me for several weeks at the end of the test, both cameras would have bear pictures.

This reminds me of a dog we had when I was young, a small elkhound puppy. After we had it 4 years a friend of my dads stopped by and this dog would not let him out of his car. It snarled and seemed like it would kill him if he got out. He left and it seemed so odd for this nice dog to go wild. Later we found out that he knew the person we got the dog from and and he had teased it when it was a puppy. Now this dog remembered being teased and identified him from his scent after 4 years.


Camera Trap Codger said...

Thanks a lot for those very interesting observations, Cliff.

randomtruth said...

Great stuff again Codger. Since I'm trapping in a fixed area, I purposely don't use bait of any kind to avoid the reward-rehabituation you theorize upon (we've already got the neighbor feeding the deer and the cougar hunting the gap between our fences!). So my empirical evidence would more fit the control side of your theory. I move my trap often and find that after a few nights/exposures (at most), the animals ignore it and go about their regular patterns. The foxes and jackrabbits come by every night like clockwork, and the bears, coyotes, cougar and bobcats come by in semi-regular cycles as they hunt their larger territories. As mentioned, the cougar and bobcats are the most rare and elusive for me - it's likely they come through the property so infrequently that I miss capturing their transits. Guess I need more cameras!

On the scent side, I think I benefit from there being lots of human scent around the property and area, and the critters have habituated to it. I do hide the traps with fragrant cedar branches too though - dunno if it helps.

If you can come up with a protocol for testing your theories, I'm happy to participate on the non-bait side.

Right now the trap is on a dead doe that we think the cougar killed. Should make for some fascinating shots as the scavengers move in. Already got some pics and vids of a gray fox trying to open the carcass (and failing).

BTW - you inspired me to start writing about my experiences with our Sierras property and camera trapping. Here's my first post looking at the various bears that visit if you're interested:


Leilani Lee said...

Just stumbled onto your blog from someone else. Local camera trapper got a picture of a mountain lion, even though Conservation Dept insisted there weren't any in Missouri. Little did they know....

Camera Trap Codger said...

Thanks for the input. Pumas in Missouri? -- wow! Thanks Leilani.

RT, loved your blog. Now I have a feel for your camera trapping territory, and congratulations on the pond restoration. That's impressive.

It would be nice to do a "meta-experiment" with several camera trappers participating. That's the way to get the sample size. First we have to agree on a hypothesis and methodology. I'll be thinking on it.

Couldn't agree more about the human scent. All the evidence shows that wildlife habituates quickly to such scent-saturated landscapes.

We'll be watching for the pictures from the doe carcass. Should be exciting.

randomtruth said...

Thanks much for the kind words Codger. BTW - I'm sure the pond work has a lot to do with our acres being so popular with the local beasties. :)

Count me in on the study. We might also be able to rally some other camera trappers via this flickr group that is specific to trappers. It has 86 members. Many are focused on deer hunting, but there are generalists too. I've had good chats with some of the folks (while often passing on your wisdom).

I'm looking forward to the deer carcass pics too - unfortunately, I don't think I'll be able to get the card until mid-January, so let's hope they're worth it!

randomtruth said...

BTW Codger - I have lots of pics and vids of woodrats running around while totally ignoring the squares of tinfoil we left out if you ever need 'em. Little rascals. :)

Camera Trap Codger said...

I think the tin foil is more attractive to the rats if it is rolled up into balls. I guess I need to find and read that article again.

randomtruth said...

We left the foil big and flat like the black oak leaves they collect for rain proofing.

Could be their gathering is seasonal, or we didn't allow enough time for them to habituate to the human scent on the foil, or we chose the wrong midden (it's in an old outhouse with a roof so the rats haven't put many big leaves on the nest), or maybe they just don't like Reynolds Wrap (brand snobs).

We had a blast trying the experiment and plan to give it another go next year. I left the foil out, so we'll see if they get around to picking some up. :)