Cameras to count tigers in Wayanad sanctuary

KALPETTA: Tigers in the Wayanad Wildlife Sanctuary will find it impossible to hide their stripes now. The Forest and Wildlife Department has installed camera traps to monitor the population of the big cats in the sanctuary.

The department, the Union Ministry of Environment and Forests, and WWF have jointly launched the project.

V.K. Sreevalsan, Wildlife Warden of the 344.44 sq.km sanctuary, told The Hindu on Sunday that nearly 15 surveillance cameras had been set up in the Muthanga range of forests and more than 100 would be set up simultaneously in the other ranges of Sulthan Bathery, Tholpetty, and Kurichyad soon.

He said dividing the sanctuary into 5 sq.km grids and field identification of tiger trails had been completed in Muthanga, Sulthan Bathery, and Kurichyad. The work in Tholpetty would be completed soon. A pair of cameras would be set up in each grid, opposite each other on a selected spot or path close to the tiger trails.

Data collection

He said the camera traps would give pictures of tigers and other animals. The cameras equipped with infrared triggers collected critical and accurate data about tigers and their habitats. Similar data of other animals could also be collected.

“We can access the same pictures to study them and their habitats and also make important decisions about their conservation,” he said.

The forest personnel would be able to learn more about various species that inhabit the sanctuary. A detailed study of animals would be possible and the photographs collected could be used later for research, he said.

A camera trap is an automated camera used to capture photographs of wild animals, V.N. Mohanraj, South India Coordinator, WWF, said.

He said the traps were installed on a site where animals were expected. When a motion or infrared sensor detected the presence of an animal, its photo was automatically taken.

Electronic eye

Usually, the camera was placed at a height of 45-60 cm on a tree, and using infrared technology, the camera captured the picture of the animal that came in its range. Day and night, the electronic eye looked for heat in motion. When an animal passed in front of the trap, the camera detected its movement and body heat and quietly snapped a photograph. Taking one-minute videos was also possible.

“Camera trapping is the primary method used where individual tigers are identified from photographs based on their unique stripe patterns. Stripes of one tiger will be different from another,” Mr. Sreevalsan said.

He said the information would be subsequently analysed using a scientific framework.

Capture-recapture method

With developments in capture-recapture method and the use of remotely triggered cameras, it was possible to capture individually marked or identifiable animals and photographically recapture them for estimating population parameters.

Since individual tigers were readily identifiable using the stripes, the capture-recapture method would be used to estimate its population.

Source: The Hindu, 01-08-2011