Blood-Powered ‘Hydraulic Toes’ Help Salamanders Master Tree-Top Acrobatics todayheadline

Scientists have discovered that wandering salamanders use a sophisticated blood-pumping mechanism in their toes to navigate the dizzying heights of redwood forests. The research, published January 8 in the Journal of Morphology, reveals how these remarkable amphibians can expertly control blood flow to their toe tips, enabling them to both grip and release from surfaces with unprecedented precision.

The discovery came about through an unlikely collaboration between scientific research and documentary filmmaking. While working on NBC’s upcoming documentary “The Americas,” lead author Christian Brown, a postdoctoral researcher at Washington State University, noticed something peculiar through the production team’s high-powered camera lenses.

“We looked at each other like, ‘Did you see that?’” Brown recalled of the moment when he and camera assistant William Goldenberg observed blood rushing into the salamanders’ translucent toe tips just before they took steps.

This serendipitous observation led to a detailed investigation using advanced imaging techniques at WSU’s Franceschi Microscopy & Imaging Center. The research team found that wandering salamanders (Aneides vagrans) can precisely regulate blood flow to each side of their toe tips, creating a dynamic system that helps them navigate the challenging terrain of redwood canopies up to 88 meters above the forest floor.

Contrary to previous theories that suggested the blood-filled toe tips aided in oxygenation, the new research demonstrates their crucial role in locomotion. The system works similarly to hydraulic machinery, with blood pressure adjustments allowing the salamanders to fine-tune their grip on irregular surfaces like tree bark.

Perhaps most surprisingly, the researchers discovered that the blood surge before “toe off” actually assists in detachment rather than attachment. “If you’re climbing a redwood and have 18 toes gripping bark, being able to detach efficiently without damaging your toe tips makes a huge difference,” Brown explained.

The mechanism works by slightly inflating the toe tip, which reduces the surface area in contact with the substrate. This minimizes the energy required for the salamander to release its grip—a crucial ability for an animal that needs to rapidly adjust its attachment as it navigates through the forest canopy.

The implications of this research extend beyond forest-dwelling salamanders. The team found similar vascularized structures in other salamander species, including aquatic ones, suggesting this blood-pressure regulation system may be a universal feature that serves different purposes depending on the species’ habitat.

The discovery could have significant applications in the field of bio-inspired design. “Gecko-inspired adhesives already allow surfaces to be reused without losing stickiness,” said Brown. “Understanding salamander toes could lead to similar breakthroughs in attachment technologies.”

The research team, which included collaborators from WSU and Gonzaga University, plans to expand their investigation to examine how this mechanism functions across different salamander species and habitats. Their findings could potentially influence the development of new adhesive technologies, prosthetics, and robotic appendages.

The study provides new insights into how these remarkable creatures maintain their grip in one of nature’s most challenging environments. As these salamanders continue to captivate scientists with their aerial acrobatics in the redwood canopy, their unique toe mechanism stands as a testament to nature’s ingenuity—and a potential blueprint for future technological innovations.