Snakes on a train? King cobras may be riding the rails in India

Snakes on a train? King cobras could ride on rails in India

By Richard Kemeny edited by Andrea Thompson

King cobras, the world’s longest venomous snakes, are showing up in parts of India where they have no business — and it turns out they might be inadvertently boarding trains to get there. As well as alarming passengers in a sort of real-life version of the 2006 film Snakes on a planeReptiles can find themselves in places where they cannot survive and, if upset, can pose a potentially fatal threat to humans.

Reports of king cobras and other snakes found at railway stations, or coiled around and even inside trains, are increasing in India. In 2017, Dikansh Parmar of the Leibniz Institute for the Analysis of Biodiversity Changes in Germany rescued an Indian cobra (Naja Naja) wrapped around the window bars of a whistling train and, of course, frightening the passengers. “He was very afraid of people. He would inflate his hood and try to show that I’m bigger than you to scare everyone,” says Parmar. “I just gently pulled it down and then grabbed it.”

In a study published on January 26 in BiotropicaParmar and his colleagues aimed to see how the snakes ended up so far from home. They used climate models to map suitable habitat for the Western Ghats king cobra (Ophiophagus kaalinga), a snake newly recognized as a full species in 2024 and found in the state of Goa. Of the 47 locations where Western Ghats king cobras were rescued across the state between 2002 and 2024, five were completely unsuitable locations, including one snake found in a port town about 120 kilometers by train from its natural range. All five outliers were found within a few hundred meters of railway tracks or stations.

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These king cobras prefer the cool, rainy mountain forests along Goa’s eastern border, rather than the dry lowlands of the state’s west, says study co-author Hinrich Kaiser, a herpetologist at Victor Valley College in California. “They need a certain amount of humidity to incubate the eggs,” he says.

Sometimes trains stop for days to collect goods or because of rains, researchers say, which can give snakes an opportunity to board. Why they would do this is unknown, although they may hunt other snakes or rodents, or seek shelter, the researchers suggest, then settle on trains to digest.

The idea proposed in the paper is intriguing but extremely difficult to test, says Emily Taylor, a biologist at California Polytechnic State University who was not involved in the research. “That’s what good science does: provide a strong hypothesis that we can continue to test as new evidence accumulates,” she says. Tracking cobras with transmitters or genetically matched distant populations could provide some of this evidence, the authors suggest.

Fortunately, even though king cobras are lightning fast and possess powerful venom, they are unlikely to attack humans unless cornered or provoked, Kaiser says. “You’re not food, so they’d much rather get out of your way.”

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