Animal underpasses on Maharashtra highway a life-saver, tigers turning out to be regular users

Last week, travellers on the newly four-laned NH-44 in Maharashtra recorded a startling video. It showed T1, a tiger from the Pench reserve, crossing the highway in daylight.

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Wildlife activists have cited these incidents to underscore the inadequacy of the nine underpasses built by the National Highways Authority of India (NHAI), on the directions of the Bombay High Court, for animals to avoid the highway.

However, a report by Wildlife Institute of India (WWI) scientist Bilal Habib and his team shows that over March, April and May, 17 different species of animals started using these underpasses along the 16-km patch of forest on the Maharashtra side of the highway — including T1.

Tigers have been among the most frequent users of at least one of these underpasses, says the report that is part of a study titled ‘Ecological impact assessment of existing and proposed road infrastructure in important wildlife corridors in India’.

The study found animals displaying “peculiar behavioural patterns” that could help in devising mitigation measures required to be undertaken in other similar projects. For instance, between March and May, the study undertaken with the help of 74 trap cameras showed that T1 used Animal Under Pass (AUP) 9 at least twice. In another case, the study showed, a sloth bear took two months to decide that it would use the underpass.

The study found that while some animals passed through the underpasses, some used them for playing or resting. Most animals used the underpasses during night, it showed. The study showed 27 events involving 11 individual tigers using AUPs 3, 4, 7, 8 and 9 — they used AUP 8 the most, frequenting it on 20 occasions.

“These are the first-ever wildlife mitigation measures in the country and the world’s biggest. Our study has found that 17 species have started using them… Tigers have been preferring the AUPs, which is very reassuring,” says Habib.

Other animals found using the AUPs were: leopard (1), chital (237), gaur (20), hare (30), jungle cat (50), mongoose (16), bluebull (15), palm civet (15), porcupine (1), sambhar (6), small Indian civet (2), sloth bear (1), wild dog (five) and wild pig (41). Langurs (6,255) and rhesus macaques (2,315) were found to have used the AUPs.

However, 10,493 people and 264 livestock also used the AUPs during the same period. “We need to restrict non-wildlife movement to exploit the full potential of these structures,” says Habib.

According to Habib, two specific developments have been encouraging:

-11 individual tigers have started using these underpasses. “This could well be the entire tiger population residing in the vicinity of NH 44 that needs to cross the road,” says Habib.

-Around 10 am last Sunday, AUP 8 witnessed a first-of-its-kind event: a pack of 5-6 wild dogs killing a chital (spotted deer). “This is very exciting since it means the dogs have started treating the AUPs as part of their habitat and are feeling at home there,” says Habib.

The underpasses, which are essentially the space beneath elevated portions of the highway, are 50-750m wide — AUPs 7 and 8 are the largest at 750m. They were constructed about a year ago, at sites most frequently used as crossing points by animals in a survey conducted by Habib in 2015, and were ready for use early this year.

In their long legal battle demanding adequate mitigation measures, in the Nagpur bench of the Bombay High Court, activists accused the WII of succumbing to pressure from the NHAI and allowing smaller underpasses than originally suggested.

After the recent video of T1, the High Court directed the litigants and their lawyers to visit the underpasses along with officials from the Forest Department and NHAI to assess the situation. The team visited the spot Saturday.

On T1 using the underpass and the road above, Habib says: “That’s a question of behaviour. Maybe, he found crossing the road on that occasion possible due to no traffic in sight. Every animal has its own calculation and response to a situation.”

Habib says the WII team has “suggested raising fencing on the road in stretches between AUPs” to deter animals from crossing. “Over the next few years, traffic will be much higher, increasing animal mortality on the road,” he says.

Udayan Patil, a member of Srushti Paryavaran Mandal, which first opposed the four-laning in court and pressed for mitigation measures, says: “There are some issues, like stacking of construction material and accumulation of water inside the AUPs. The guiding walls, too, have to be of appropriate height. As for the validity of the WII’s claims on the utility of the structures, we need to have other independent agencies cross-check with their own data.”

Pench Tiger Reserve (PTR) Field Director Ravikiran Govekar says that “overall, the mitigation measures have started bearing fruit”. But he is quick to add that it’s too early to arrive at a conclusion. “The Wildlife Conservation Trust (WCT) has also been asked to do their own assessment. We will have to do a study for about a year to be able to fully understand the pluses and minuses of the mitigation measures,” he says.