Salamanders fill their toes with blood before each step

How salamanders manage to move around on uneven, vertical tree surfaces with such dexterity has long baffled scientists. A new discovery suggests they use a trick out of a horror movie: filling their toes with pools of blood.

While Christian Brown at Washington State University was observing wandering salamanders (Aneides vagrans) through a close-up camera in 2021 in a coastal redwood forest, he noticed blood moving in a rhythmic pattern under their translucent skin. Before lifting their foot to take a step, blood inundated the tips of the salamanders’…