Bird Anatomy: Bills and Feet
Birds bills (beaks) and feet are highly specialized largely
due to the birds lack of arms and hands. Bills and feet perform
many functions other animals do with their forelimbsreach,
grasp, pick-up, manipulate food, climb, carry. You could probably
figure out what niche in the environment a particular bird occupies
and what type of food it eats simply by observing its bill and
feet.
BILLS
Birds bills have different shapes to help them reach for,
pick up, and manipulate things, especially food, as the need arises.
Consider the bill shape and food source of a few well known birdseagle,
hummingbird, cardinal, woodpecker, nuthatch. Eagles, like most
raptors, have large, hooked bills adapted for tearing apart their
prey, which in the case of the bald eagle is usually fish. Hummingbirds
have a long, narrow, straw-like bill for sipping nectar from trumpet
shaped flowers and hummingbird feeders. The cardinals heavy, conical
bill is perfectly shaped for cracking open large seeds. The woodpeckers
long, heavy bill allows it to excavate cavities for nesting and
probe into tree bark crevices looking for insect prey. Nuthatches
also use their slightly upturned bill to search for insects in
the bark of trees as they climb down the tree headfirst!
FEET
The feet, especially the toes, can tell you a lot about birds.
If ducks and geese didnt have webbed toes how would they
propel themselves through the water? The talons of birds of prey,
like the eagle, help them catch their prey and hold on to it while
they eat it. Check out the feet of the birds at your feedersmost
backyard birds have three toes facing forwards and one toe facing
back. But look at the woodpeckers feet, why do you suppose it
has two toes facing front and two facing back? This toe configuration
allows the woodpecker to balance and climb up and down the bark
of trees.
The next time you get a close-up look at a bird in your backyard,
see if you can figure out where it lives and what it eats just
by the shape of its bill and feet!