Adaptations:The Legs and Feet
for labeled photo
Get a Grip!
In order to grasp and carry live fish, eagles need strong legs
and toes, and a powerful grip. An ornithologist looking at an eagle's feet would
know that this bird is a hunter that
specializes on underwater prey. How? Because eagles have talons and no
feathers on their legs.
feet have claws, but so do the feet on dogs, cats, squirrels, raccoons,
robins, and even tiny hummingbirds. What makes eagle feet different?
First, the claws must be extremely strong and sharp. When an eagle
catches a fish, those claws have to slice into a stiff, strong
fish with thick scales protecting its body. (All birds of prey
use their feet for killing, from the tiniest Elf Owl and American
Kestrel to the largest eagles.)
sharp claws are NOT the reason eagle feet are called talons; after
all, cats have sharp claws, too, but they don't have talons. What
makes talons different? They are designed to carry things. An eagle
foot is made up of four muscular toes, powerful enough to hang
onto a fairly large fish as the eagle carries it through the air.
A cat can't carry a mouse in its claws!
hunting birds have feathers on their legs to protect them from cold.
Eagles do not because they prey on fish; feathers on the legs would
drag on them, slowing them down.
hawks, and owls have very sharp beaks as well as talons. Many of them
use their talons to grab prey animals. Next they use the sharp points
of their beaks to bite the animal at the base of the skull or in the
neck to kill it. Eagles don't bother with that when they're carrying
a fish, but ones that learn to hunt rabbits or ducks may do so. Although
an eagle's beak is strong, powerful, and huge, it rarely if ever carries sticks
or fish in its beak.
you think of some reasons why eagles always carry items in their
talons rather than their beaks?
North students came up with at least 14 different reasons! Here are
three answers from bird expert Laura Erickson, followed by the terrific
ideas students provided:
Science Education Standards
plant or animal has different structures that serve different functions
in growth, survival, reproduction.
systems at all levels of organization demonstrate the complementary
nature of structure and function.