Five invasive brown tree snakes (
Boiga irregularis) were spotted climbing vertical metal cylinders about 15 to 20 centimetres in diameter that were holding up bird boxes. To do so, they wrapped their bodies around the pole and hooked their tail around their midsection, allowing them to wiggle upwards to reach prey.
“The loop of that lasso shape is effectively where all of the action is, because that loop squeezes on the cylinder to prevent the snake from slipping down,” says Bruce Jayne at the University of Cincinnati in Ohio.
Only four other types of locomotion have been observed in snakes until now. Compared with the other forms, this new type is “painfully slow”, says Jayne.