As spring’s crescendo of birdsong mellows now to a steadier summer trill, I listen for melodies I don’t recognize and try to figure out which birds are singing. I look through binoculars at their feathers, the color variations along head and chest, the size of their beaks, the shape of their wings, and the tilt of their tails in my flailing attempts to distinguish one species from another. Rarely have I considered feet in my casual observations, although this part of a bird’s anatomy can be highly specialized for various uses.
“When you look at the foot of a bird, they’re not all the same,” said Kevin McGowan of the Cornell Lab of Ornithology. “All the birds basically started off with three toes forward, one back. From that, they’ve evolved in a number of different ways for various reasons.”
Birds walk on those toes – not the entire foot. The backward-bending joint we may consider a knee is actually the birds’ ankle. The feet consist mainly of bones and tendons, with very little muscle and few blood vessels. » Continue Reading.