These tiny birds scurry up and down beaches all over the world. What about their feet lets them run so fast?
This is a Sanderling, one of the most widespread shorebirds on Earth. As with Ostriches and some other fast running birds, Sanderlings lack the toe that faces backwards. This lets them extend their feet forward further, without snagging the rear toe on the ground. This gives them a longer stride, and a smoother gait to get more speed.