King cobras may be riding trains, away from habitats

When a king cobra turns up at places it should not be in, the explanation may not always be habitat loss or climate change. Sometimes, it could be the morning train.

Research by herpetologist Dikansh Parmar and team, titled ‘Snakes on Trains: Railways May Sway Goa’s King Cobra Distribution’, published recently in the journal ‘Biotropica’, suggests India’s vast railway network may be unintentionally ferrying the apex predator far beyond its usual habitats.

Using over two decades of rescue records in Goa, of the Western Ghats king cobra, a species endemic to the state, Parmar found that of the 47 locations from where the snake was rescued, five were completely unsuitable habitats, all within a few hundred metres of railway tracks and stations. One snake was found in the port city of Vasco, 120km away by train and far from the rainy forests it normally prefers. (See map) Parmar, affiliated with the Leibniz Institute for the Analysis of Biodiversity Change (LIB) in Bonn, said he believes the snakes may be entering train compartments for shelter or prey. Rat-infested goods wagons make for particularly good hideouts, he added, because of prey availability.

This accidental transport of snakes via a rail network may sound unusual, but such incidents are likely underreported, Parmar said. “One indication of this is the increased reporting in recent years of snakes on trains on social media,” he said.

The consequences of accidental relocation are not trivial. “Many snakes are highly adaptable, but king cobras have very specific habitat, prey and microclimatic needs, and being moved into unsuitable environments may significantly reduce chances of survival,” said Parmar.

Snake rescuers in Goa told TOI a variety of snakes — not just king cobras — have been rescued from locations near railway tracks.
“We found a pit viper once, inside a scooter that was parked near a railway station,” said Amrut Singh, from Animal Rescue Squad, in Bicholim.

Benhail Antao, honorary wildlife warden of Goa forest department and host of ‘Snakes SOS: Goa’s Wildest’ on NatGeo India, said unintentional movement of wildlife has been happening since the dawn of transport, “via trains, ships and trucks”.

“We see it with reptiles, birds, frogs and lizards,” Antaon said, while recalling an incident in which a bamboo pit viper, which prefers the cool conditions of hilly forests, was found in humid Mapusa, most likely transported there by fruit trucks.

“This is also not unique to India. Blind snakes and worm snakes that live in soil and feed on termites have been found transported with potted plants to the UK,” Antao said, adding that such relocation puts species and ecological balance at risk. “A king cobra in Vasco cannot survive for long,” he said.

P Dennis Röder, professor at LIB and co-author of the research with Parmar, said: “Artificial dispersal corridors created by human infrastructure may profoundly influence how species are reorganised across landscapes.”