July 30, 2012

More Photographic Oddness at Camera Trap Spring

As previously mentioned, I switched scout cameras on June 15th at Camera Trap Spring, replacing the previous bear-damaged (but productive) camera with one that was (a) heavier-built and (b) of less value.

Bottom opening lacks cover.
Today, after five and a half weeks, M. and I went to check it. It is an 80 or 90-minute round-trip hike from the house, pretty aerobic, and when the temperatures were in the mid-90s F., we just did not feel like going up there.

Tapping like a blind man with my walking stick to alert the "guardian of the spring" — the rattlesnake that was there in May and June — I approached the site.

The spring was dry — no surprise. We saw no snake.

The camera was all right  . . . no, something was missing.  The grey plastic cover of the infra-red detector was gone. I found it lying in the pine duff with an indentation that looked like a claw mark. There were faint scratches on the camera body.

Obviously a bear had given it a light tap.

I brought it home. There were something like 689 images, all recorded between June 19th and July 3rd.

Bull elk in velvet checking the spring, June 29, 2012.

There was one clear animal picture — this elk — but none of the bear.

The camera had been making a picture every one to four minutes from early afternoon until early evening, every day. Made for an interesting time-lapse slide show.

I suspect that the bear knocked the IR sensor cover off early. The cover, made of flexible plastic, has mini-fresnel lenses molded into its inner side, which would, I assume, focus infra-red radiation onto the sensor.

The camera started responding simply to heat reflecting off the forest floor on the hot afternoons and shot photo after photo until its 512 MB memory card was full. That's my hypothesis.

1 comment:

Anonymous said...

Interesting...I have a camera that does that same thing occassionally. A Cuddeback Attack FLASH though, not IR. It spotaneously will take pictures at 1 minute intervals for an hour or so, then stop. And also NOT respond to critters (or me) in front of it. I think I have a lemon.