The unusual feature that helps salamanders glide over the world's tallest trees

Slippery salamanders glide mysteriously through the canopies of the world’s tallest trees. Now, scientists say they understand how the small skydivers are able to maneuver seamlessly across California’s coastal redwoods.

The answer might be surprising. Wandering salamanders can fill, trap, and drain the blood in their toe tips to help them easily attach and detach to the bark of the trees.

Christian Brown, the lead author of new and related research and an integrative physiology and neuroscience postdoctoral researcher at Washington State University, first noticed it during filming for the NBC documentary The Americas. Bright red blood rushed to the creatures’ translucent, square-shaped toe tips before they took a step forward.

The hindfoot of a wandering salamander is seen just before it takes a step forward. Scientists say its blood-powered toes help this salamander moves hundreds of feet in the air (Photo by William P. Goldenberg)

“We looked at each other like, ‘Did you see that?’” Brown said in a statement.

The university-led findings were published Wednesday in the Journal of Morphology.

Using camera equipment from the production, high-resolution video helped the researchers to analyze the mechanism.

Regulating blood flow, the authors said, allows the long-legged wandering salamanders to adjust pressure asymmetrically. Blood rushing in before the “toe off” helps them to detach.

And, by inflating the toe tip, the salamanders reduce the surface area in contact with the one they are on. That minimizes the energy they need to let go and parachute between branches.

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Flying squirrels, gliding frogs, geckos, ants and other insects are known to use similar aerial maneuvers, according to researchers at U.C. Berkeley.

“What struck me when I first saw the videos is that they (the salamanders) are so smooth — there’s no discontinuity or noise in their motions, they’re just totally surfing in the air,” Robert Dudley, a professor of integrative biology at the university, said in 2022.

A wandering salamander, also known as Aneides vagrans , clings to a camera lens during a scientific investigation of their jumping, parachuting, and gliding behaviors. Other salamanders exhibit similar mechanisms that allow wandering salamanders to thrive in coastal redwoods (Photo by Christian Brown)

Brown and Dudley worked together on a previous paper that described their movement and how they can control falls from hundreds of feet in the air.

Previously, the feature was believed to aid the wandering salamander’s oxygenation, but the researchers said there was no evidence to support that theory.

Similar structures are found in other salamander species that might serve other purposes. More research is needed to understand how it works to serve those species in their habitats.

“This could redefine our understanding of how salamanders move across diverse habitats,” Brown said.

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