Like other birds of prey, eagles have very special feet, which are different from those of other animals. We call those special feet talons.
Makes Talons Special
But 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.
Eagles, 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.
are Second Best
How does an opposable toe help an osprey catch fish? When an eagle holds a fish, it has the front toes from both feet on one side of the fish (6 toes) and just the back toes (2) on the other side of the fish. Ospreys catch their fish with two toes from both feet on each side of the fish. This is more balanced. Fish thrash their bodies back and forth when they are struggling against being caught. If they thrash away from an eagle's front toes (with no back toe pushing the opposite way), the fish may actually jerk itself out of the eagle's talons. If the eagle is over water, it's even possible that the fish will survive the fall and its injuries may heal. A fifth-grade boy in Duluth, Minnesota once caught a walleye that had six scars on one side of its body, and two scars on the other, exactly the size and shape of eagle toes!
National Science Education Standards