I ran this post by Cliff Wheeler, a seasoned woodsman and one of the best camera trappers around, and I am happy to say that he shares my views. If you haven't been checking his blog, well, you've been missing a lot of great wildlife images and tips on camera trapping.
So getting back to the lecture, here’s how we see it.
Point 1) Despite our best efforts to hide them, our cameras don't go unnoticed.
- Birds and mammals detect trail cameras by sight and scent.
- Hiding a camera delays discovery and increases the chance of getting a candid picture. Cliff says, " disguising the camera with vegetation is much more effective than the camo on the camera case”. When he places a camera on a tree he covers it with moss, "but only for deer or coyotes, since most other animals seem to care less".
- The sound of the extending lens seems less noticeable than the sight of it, at least in daylight. Digital cameras don't make shutter noise, and camera trappers usually deactivate the cute electronic noises that come with the camera.
- Most people can't hear the lens murmur inside the case, and it's doubtful many animals can hear it when there is wind, rain or nearby streams. However, some of the latest commercial trail cameras have a tone designed to alert the passing deer, so it pauses for its photo looking like a taxidermic mount.
- Most mammals can probably detect the camera by scent, at least when downwind.
- Most mammals and birds seem indifferent to the flash. Like people they sometimes anticipate it and blink, or avert the eyes.
- Looking at the flash at close range temporarily affects vision by causing image bleaching. That's how it affects people, and it's probably the same for many mammals. The effect is minimal in daylight, but intense in darkness when the pupils are open. The undesirable photographic result is red-eye and disturbance of the subject.
- You can reduce the effect by using an external flash. If the subject looks at the camera, it won't get a head-on blast of light. If you set the camera for automatic exposure, flash intensity adjusts to the proximity of the subject. If you also set the camera for red-eye reduction a volley of low intensity flashes precedes the flash. This stimulates pupil closure and reduces reflection from the retina.
- There is no behavioral evidence that the flash affects vision of animals more than it does humans.
Point 2) The response to the flash differs among species, but not all individuals react in the same way.
- Rodents rarely show any reaction to the camera or flash. They feed, gather seeds, and return to a feeding site despite the flash. Occasionally a wood rat or squirrel will climb on the camera.
- Birds have wide angle vision, so it is difficult to tell if they are looking at the camera or are viewing a much larger area. They often carry on despite the flash.
- Deer occasionally show curiosity to a camera, but elk often sniff, lick, or rub antlers on the camera.
- Coyotes are usually camera shy. You are lucky to get more than one exposure. Yet they may be bold in areas where there are a lot of people who don't harm them, or when scavenging at a carcass in winter. Cliff notes that sound is an important consideration when setting cameras for close-ups. "By setting the camera low to the ground, say under 12 inches and next to some brush, I have been able to get multiple pics of coyotes easily at night or during the day."
- Bears differ in their response to cameras. In some regions they are indifferent, but in all areas there are curious and destructive bears. We believe the flash stimulates their curiosity. A bear can't play with a mouse without killing it, and can't examine your camera without making permanent adjustments to its workings.
The evidence tells us that camera traps do not hurt wildlife or disrupt the lives of wild animals in any harmful way.