By Elizabeth Pennisi
Some robots swim and dive through the water; others scurry across the country. Now researchers want to build a machine that can do both. Their inspiration? The California Sea Lion.
Although they have a reputation for being lazy, sea lions are fast and gracefully underwater. They can also climb it on land, gallop up to 6.7 meters per second over beaches and even climb up and own rocks. (People are about one-third as fast.)
To help the engineers design a potential land-sea robot, a student recorded three trained California sea lions (Zalophus californianus) when they galloped down a short runway outside (see video above), they analyzed their gait. She compares the passage to that of elephant seals – which are more than twice the size of sea lions, but also spend time on land. The data showed that the sea lion has the ability to pull its rear flippers under its body so that it “walks” like a land animal, which offers an important advantage for speed and agility.
True seal hind wings are on the side of the body. Consequently, elephant seals can move just like a thumbworm, lift their bodies high in the air, drag their stern vessels under that mass, and finally pull themselves forward with their front limbs. Sea lions do not have to lift their bodies so high, the graduate student reported this week at the virtual meeting of the Society for Integrative and Comparative Biology. They can also sync print pieces with their rear flippers.
The researcher calculated the power output of the sea lion and found it to be more efficient than even harbors and gray seals, making it significantly faster and a better choice to inspire a robotic mammal. So much laziness.