It’s something that has undoubtedly puzzled many a backyard birder—how do their beautiful birds manage to sleep while perched precariously on nothing more than a tree branch? Looking at them, it would appear that nothing more than a slight breeze would be able to knock them over while they snooze. And yet, they are able to stay upright all night long. Well, wonder no longer, because this blog post is going to shed some light on why birds are able to do this. The answer lies in their feet, specifically their toes.
While birds generally only have four toes—three of which arch forward, with the other pointing backwards—they are similar to humans’ hands in that they serve a primarily utilitarian function. In other words, birds are much more adept at using their feet for tasks than we, as humans, are. Unlike the uniformity of human feet, bird feet vary wildly depending on what each species needs to do with them. In the case of songbirds, they are normally found standing on their toes, as opposed to the flats of their feet as humans do.
So why then are songbirds so adept at holding onto branches, even while asleep? The answer is found in their anatomy. When a bird lands on any kind of perch, there is a tendon on the back of their leg that automatically tightens and locks their toes around whatever it is the bird is on. This is an involuntary reflex, so it occurs without any kind of conscious effort on the part of the bird. To release the lock of the tendon, the bird can simply straighten its legs.
Other backyard birds have different adaptations to accomplish the same thing. Woodpeckers, for instance, have two toes pointing forward and two facing backward, which allows for greater balance, while nuthatches have stubby legs that hug the ground and provide more balance than longer legs. Nuthatches also have very long toes and claws that face downward, which allow for excellent grip on any kind of surface.
Now you can amaze all your fellow birders with your new-found knowledge of why birds can sleep perched on nothing more than than a tiny branch without falling over. Happy Birding!
Written by Guest Writer Sean Peick