New Delhi: Projecting a bright picture of tiger conservation, the number of big cats in the Terai region has grown significantly with at least 71 new adults roaring, say reports from the latest Phase-IV of monitoring.

The highest rise so far has been recorded in Uttarakhand’s Western Circle — a huge part of the vast Terai region of the state located outside the tiger and forest reserves — where the figures went up from 79 in 2014 (last census) to at least 119 adults till last year, officials said.

Meanwhile, at Kishanpur Wildlife Sanctuary and Dudhwa National Park of Dudhwa Tiger Reserve, situated in the Terai region of Uttar Pradesh bordering Nepal, the number of tigers has increased from 53 in 2014 to at least 79 adults.

Experts believe the reason for such a boom is the “heterogeneous and complex landscape” of the western circle that supports the species better because of automatic “niche construction”.

Niche construction or ecosystem engineering is a process in which organisms modify their environment for survival.

“In such complex landscapes, unlike homogeneous landscape of a typical forest, prey density for animals is good because a niche for different animals is automatically created,” said Dhakate.

The numbers in Assam’s Manas National Park, also part of the Terai landscape, have also risen though the final results are awaited, officials said.

The Phase-IV monitoring was conducted in a few forest divisions including the West Circle of Uttarakhand and parts of the Dudhwa Tiger reserve in 2016. The monitoring is under way in some reserve forests including Corbett and Manas, and yet to be conducted in several other parts of the country.

“The number of tigers has increased significantly. Over 50 adults have been identified for the first time,” Dr Parag Madhukar Dhakate, Conservator of Forests, Western Circle, told IANS.

A good number of cubs were also counted but officials requested that the numbers be not disclosed.

“All tigers and cubs were healthy. It projects a good prey-predator ratio,” Dhakate said.

The western circle spreads over 2,573.6 sq km (from Haldwani to Ramnagar) comprising 60 per cent natural forests and 40 per cent plantations.

The figure projects distribution of a breeding population of tigers living outside reserve forests in a complex landscape which also include agricultural fields and human encroachments.

The Phase IV monitoring of the western circle is an independent census (self-initiated) and one of the firsts in the country conducted over a large area. It started in January 2016, officials said.

“The monitoring was carried out for 214 days using 250 camera traps used at 393 locations. A total of 16,457 images were obtained,” Dhakate told IANS, adding that the mission included 500 people.