Sunday, June 7, 2009
Improvising with camera traps
One of the recent advancements in the field of wildlife monitoring is the improvement and increased usage of “camera traps”. A camera trap is basically a camera with a remote trigger connected to infrared sensors, mot ion detectors and heat detectors replacing the conventional shutter release button. This contraption when set up on trails, ponds and other places where there is evidence of wildlife movement, will take a picture of the animal passing in front of the camera. Camera traps have been used extensively to monitor wildlife populations since the time of its coming into existence. Lately, it is being used to estimate the number of tigers in a given area besides capturing rare behavior and the existence of other lesser seen fauna, monitoring the populations of critically endangered species like the Snow leopard in the Himalayas and so on. These easily available camera trap units have also been used in many other conventional and not so conventional situations like near the nest of an owl by TNA Perumal, who got scratched by the owl in the process, but was rewarded by fantastic flight images of owls and many interesting feeding habits which was never seen or documented before. Some of us at ATREE have been successful in using these camera traps to capture the first ever tiger picture from KMTR , obtaining rare images of the Pigmy Hog and the leopard cat from Manas tiger reserve, to capturing the lives of arboreal mammals in forest canopies. Quite recently, we implemented the camera trap in more unique situations. This was during the annual Sorimuthian festival, to document the movement of wildlife during the festival season and in another case during the pre harvest paddy season, in the plains of Singampatti, to capture the occurrence of rodent feeding owls. Though both were by and large failures, they taught us great lessons which will enable better deployment next time. In the former case, the camera traps were discovered by the forest patrol staff and enthusiastic children, who then proceeded to pose in front of the camera triggering the entire film roll. All we got were a few laughing faces of homosapiens. The latter case was a trial run and un-loaded cameras were deployed to see if it would work. In order to make the owl trigger itself, we setup rodent feeding trays in a paddy field getting ready for harvest. The camera traps were fitted on to improvised posts made of discarded plastic water pipes and entrenched in the field. A perch was created for the owl in the field, overlooking the entire field. Though nothing much happened in this experiment, for the owls or the rats turned up, we were all delighted and relieved to find the camera traps in the place just as we had left it! We also learnt that the traps and the rodent feeding trays had to be left in the field for a few days for the rodents to acclimatize to it. Of course, the big lesson of all was that there weren’t any rodents in that field for the owls to come and feed. The only way to get owls to come would have been to release a couple of rodents into the field!