This really sounds like a dumb question in my head. But I think it’s pertinent; have you ever looked at a bird, and thought about their skinny legs? They don’t appear to have any muscle or fat on them do they?
Seeing the picture above of the stork, their body seems disproportionate to their legs. But remember, birds have very hollow and lightweight bones. They are very light relative to their size, plus they are covered in feathers which conceals their true size. So they don’t need much of that bulky meat on their legs. In fact, for the lower part of their leg it’s not even part of their anatomy. Let’s have a look:
The picture above is a demonstration of how a pigeon leg works. The perching mechanism describes how the bird is able to perch via the retraction of their tendons, so they don’t fall off their perch when they sleep for example. Anyway, Britannica have kindly labelled the image with some anatomy. You see where the heel is? That is where our heel would be if we were turned into birds. And notice where the femur is as well; so that means the bird’s knee is just below that.
So the reason there is no visible fat or muscle around the lower end of the bird’s leg is because that is technically their foot and toes, which naturally contains very little mass. Essentially it’s just bone and tendons, just like ours but stretched out a lot. The bird version of the calf muscle and thighs are much higher up, respective to where their heel, knee and femurs are.
Of course, size matters.
The larger the bird, the larger their legs and feet. And of course large flightless birds like ostriches, emus, cassowaries, etc will have a lot more bulk to their leg muscles. But the anatomy is still the same; they all walk on their toes.
Originally published at http://haveyoueverwondered123.wordpress.com on May 29, 2022.
