These Snakes Found a New Way to Slither
The novel technique is great news for Guam’s brown tree snakes, bad news for the island’s nesting birds.
The brown tree snake was introduced accidentally to Guam in the 1940s, decimating the population of native birds, including Micronesian starlings.Credit.Bjorn Lardner, United States Geological Survey
By Sabrina Imbler
Published Jan. 11, 2021Updated Jan. 12, 2021
In 2016, on the northern tip of Guam, two biologists, Tom Seibert and Julie Savidge, challenged several brown tree snakes to a battle of wits. The arena: a concrete pen with a narrow metal pole. The prize, at the top of the pole: two mice, a seed cake and a potato in a cage. (The potato and seed cake were for the mice.) The obstacle: a three-foot-tall metal stovepipe baffle cinched around the pole like a cummerbund.
Jan. 11, 2021 , 11:00 AM
The brown tree snake is an ecological menace on the island of Guam, where it has gobbled up nearly all the native birds since its accidental introduction more than 70 years ago. To save the U.S. territory’s remaining birds, researchers placed nests on top of smooth poles they were sure no snake could climb. But they were in for a nasty surprise: In 2016, video captured the snakes climbing the cylinders, with a never-before-seen lassolike gripping technique.
“To say I was surprised would be an understatement,” says Bruce Jayne, a biologist and snake expert at the University of Cincinnati. “I’ve never seen anything like this.”
Scientists have identified an entirely new mode of snake locomotion. The newly documented climbing behaviour is difficult, but allows snakes to impressively shimmy up large, smooth cylinders.
Snakes do a lot more than slither. Some swim, while others sidewind across sand (
SN: 6/29/20). But no one has ever seen a snake move the way that brown tree snakes do when they climb certain trees. By wrapping its tail around a tree or pole in a lasso-like grip and wriggling to propel itself, a brown tree snake can shimmy up structures that would otherwise be too wide to climb.
Better understanding how brown tree snakes (
Boiga irregularis) get around could inform strategies to control their population in Guam, where the snakes are an invasive species. The reptiles are infamous for having wiped out almost all of the native forest birds on Guam and frequently cause power outages by clambering up utility poles.