Roads versus wildlife in Karnataka’s protected areas

The Nagarahole-Bandipur-Mudumalai-Wayanad belt and its adjoining areas, in the southern state of Karnataka, is one of the best landscapes for the conservation of tigers, elephants, dholes and other large wildlife in India, according to wildlife conservationist Sanjay Gubbi. “With our vehicular density increasing by 10-12 percent annually we should keep this landscape sacrosanct from new road development and the expansion of existing roads.”

Protected Areas (PAs) constitute about 4.99 percent of India’s landscape and are categorised into National Parks, Wildlife Sanctuaries, Conservation Reserves and Community Reserves. And while the primary purpose of this network of PAs is biodiversity conservation, linear infrastructure intrusions like roads, railways and power lines happen to be one of the strongest challenges faced by such ecological landscapes.

In a developing nation like India, the impetus provided to infrastructural projects fails to take note of ecological impact which is especially troublesome in the case of PAs, where such projects could lead to disturbances, habitat fragmentation and wildlife-vehicle collisions (WVC) and ensuing mortalities.

Killer roads

According to studies conducted by Gubbi and team, during the period between 2010 and 2017, 130 chital, 26 sambar, 27 sloth bears, two elephants, two hyenas and one tiger were killed in Karnataka owing to WVC. What makes the statistics worse is that these numbers are only those that got reported; there are probably multiple cases of non-detection. Moreover, injuries are usually missed and only mortalities are reported.

A recent, as yet unpublished study by independent researcher Aparna Kolekar (now at the University of Exeter) assessed the impact of traffic density and road-widening on roadkill. The World Wildlife Fund-funded study found that mammal-vehicle collisions (MVCs) were recorded across 80 percent of the state of Karnataka. Although National Highways (NHs) constitute only 12 percent of the total road length in Karnataka, they recorded the highest number of MVCs.

At 8.3 metres, NHs have the highest mean road width; this indicates that road width plays a major role in MVCs, Kolekar said. She noted that road widening projects should not be allowed in order to reduce MVCs in PAs and other critical wildlife landscapes. She also suggests mitigation measures like road humps, diversion of roads and night closure in landscapes where the priority should be wildlife.

“Aparna’s study is unique and highlights the impacts of vehicular movement on wildlife and has clearly brought out interesting results,” Gubbi noted. “More importantly, it was carried out within a critical wildlife corridor (Doddasampige-Edayarahalli), and hence shows that even a small stretch of road passing through a corridor can have a larger impact on animal dispersal, movement and could affect an entire landscape. It also highlighted that forested corridors were critical for wildlife movement compared to agricultural fields.”

Roads alter animal behaviour

Apart from wildlife mortalities, road traffic has been observed to have an impact on the behaviour of animals. A 2010 study documents motorist-elephant interactions in the Mudumalai Wildlife Sanctuary, where Asian elephants can be seen at one of their highest densities.

The study notes that elephants became agitated or showed other extreme responses in 20 percent of the cases where motorists just drove past them. Elephant herds which were subjected to noises made by motorists, including teasing, became agitated in over 50 percent of the cases. Disturbances in elephant behaviour were also noted when elephants had to wait long periods to cross the road owing to traffic density.

In the long term, such behavioural responses might lead to animals completely avoiding routes that traverse through roads, the authors note and call for a similar study to be conducted in other habitats over longer periods so as to assess changes in animal behaviour owing to liner infrastructure intrusions like roads.

Another case in point to reflect on road ecology in India is the recent happening concerning the Bandipur National Park.

In a letter to the Karnataka Chief Secretary on July 21, 2018 the Ministry of Road Transport and Highways (MoRTH) called for the consent of the Karnataka government to lift the night-traffic restriction on NH 766 passing through the Bandipur National Park, widen the current right of way (RoW) width to a uniform 15 metres, develop elevated stretches of one kilometre each and install steel-wired eight-feet high fences on both sides of the road.

“The suggestions made by the Ministry in the letter have been discussed at various forums, expert committees, including in the high court of Karnataka and have not been found to be feasible,” Gubbi said. “Increasing road width will lead to higher WVC and it will isolate wildlife populations by acting as a barrier for their movement. Moreover, Bandipur Tiger Reserve is notified for the protection of wildlife and accordingly, wildlife should take precedence and not concrete construction projects.”

Amid strong opposition from the state’s conservationists, the government of Karnataka stated that the night-traffic ban will not be lifted and neither will flyovers be allowed to be constructed through Bandipur.

Gubbi noted that the Karnataka state’s decision is a stand in favour of wildlife and suggested, “My opinion, based on experience from this landscape and evaluating it scientifically, is that we should make the existing alternative highway – Hunsur-Gonikoppa-Kutta-Mananthavady – a high speed road. Some parts of the alternative route passes through the edge of Nagarahole Tiger Reserve and Wayanad Wildlife Sanctuary and here we should build an elevated road. This will reduce the time taken to reach Wayanad and also help wildlife.”

A committee appointed by MoRTH to submit proposals on the matter has endorsed plans to lift the night-time closure and to build elevated corridors and fences despite a report by the National Tiger Conservation Authority (one of the members of the committee) advising against such measures. Moreover, the Karnataka Forest Department – a key stakeholder – was not appointed as a member of the committee which was constituted by the MoRTH.

“Importantly, the committee is suggesting the construction of these flyovers based on a report developed by Wildlife Institute of India,” Gubbi said. “But on the contrary, the report suggested: ‘First, avoid or prevent adverse impacts as far as possible by considering  or design alternative. Where impacts are highly significant or could lead to loss of irreplaceable biodiversity or conservation assets, avoidance is the only real option if development is to be sustainable’. Hence the committee has misrepresented facts before the honourable Supreme Court.”

Need for thorough environmental assesment

The other concern is regarding the methods employed to assess the ecological impact of road development projects is India.

Another study by Gubbi, H. C. Poornesha and M. D. Madhusudan documented the impact of vehicular traffic on the usage of road edges by large mammals along the Mysore-Mananthavadi Highway which passes through a crucial wildlife corridor in the southern part of Nagarahole.

“Our study highlighted how stretches of the road without vehicular traffic was used by all wildlife species both during the day and night time,” said Gubbi. “Some wildlife species completely avoided stretches of this road when there was vehicular traffic, but used the same stretch after vehicles ceased to ply.”

The study also highlighted how highway edges created micro-habitats, partly owing to the presence of abundance of grass which attracted herbivores. This higher density of herbivore species like chitals, gaurs and sambars lead to an increase in road-kill susceptibility. The study also found vehicular speed and traffic density as important factors affecting road-kill.

Drawing from the above studies, the authors noted that a major issue concerning Environment Impact Assessments (EIAs) is the fact that it does not call for a continuous post-implementation assessment of infrastructure projects in PAs. Therefore, “unforeseen impacts” are never accounted for and consequently, appropriate mitigation measures do not get identified and implemented. The other problem with EIAs, the authors note, is that while they are a step in the right direction on paper, they are “highly prone to misuse” since such assessments are conducted largely by personnel who are hired by the project proponents themselves.

“The study also brought to light how the EIA was biased against wildlife interests, including the opinions given by some members of civil societies who claim to be saving wildlife,” said Gubbi.

And as a remedy, the authors called for a stringent peer-reviewed assessment process by wildlife biologists in the hope that ecological safeguards like EIAs ought to be in place while the nation aims towards economic growth.