Homing trick of the Burmese python surprises scientists

Snake can head home in a near-straight line even if released dozens of kilometres away

PUBLISHED : Wednesday, 19 March, 2014, 12:28pm
UPDATED : Wednesday, 19 March, 2014, 4:34pm

The Burmese python has a built-in compass that allows it to slither home in a near-straight line even if released dozens of kilometres away, researchers said on Wednesday.

Capable of growing over five metres long, pythons are among the world’s largest snakes. Although native to South and Southeast Asia, including Hong Kong, the snakes have taken up residence in South Florida’s Everglades National Park, possibly after being released as unwanted pets.

They have adapted so well to their new habitat that they now pose a serious threat to several species which they hunt as prey.

Scientists captured six of the pythons in the Everglades, placed them in sealed, plastic containers, and drove them to locations between 21 and 36 kilometres away.

They implanted radio trackers in the animals and followed their movements with GPS readings from a small fixed-wing plane - measuring their direction and speed.

All the snakes immediately oriented themselves towards the place where they were captured, with five of the six returning to within five kilometres of that spot.

The sixth veered somewhat off course as it was nearing its destination.

The Burmese python, a non-venomous and endangered species, is the only protected snake in Hong Kong, where most snakes are harmless.

It is believed there are hundreds in the New Territories. They can live up to 30 years and eat everything from tiny birds to deer and even alligators, swallowing their food whole.

In 2007 a three-metre-long python killed a goat in Tseng Lan Shue, Sai Kung, after constricting it and trying to swallow it whole. Although villagers were able to eventually separate the goat from the snake, it died.

Pythons have also attacked large dogs on the Pak Tam Chung walking trail on the edge of Sai Kung Country Park, crushing one to death in 2006 and nearly killing another the following year until the dog’s owner wrestled the pet away.

Last year a three-metre-long python was seen on Lamma Island, near the end of the ferry ramp in Yung Shue Wan.

All pythons that have been captured in Hong Kong have been microchipped and released back into the population as part of a pilot project launched in 2010 that aims to monitor the python population in the territory.

They were previously transported over the border and released, a controversial practice as they are hunted in China for their meat and skin and are sold on the black market for thousands of yuan.

The snakes in the study travelled between 94 and 296 days, displaying “high motivation to reach home locations”, according to the study, published in the Royal Society journal Biology Letters.

“This study provides evidence that Burmese pythons have navigational map and compass senses,” the authors wrote.

No other snake species has yet been shown to possess a similar homing ability.

Such navigational skills suggest the python has a razor-sharp sense of territoriality. This could help combat the species in places where it is unwanted by predicting where the snake is likely to spread.