What makes a bird a raptor?
Birds of prey, or raptors, are the main reason the NCA was given special legislative protection. It is the unique combination of soil, climate, geology, and vegetation that has created an ecosystem where nesting birds of prey occur in extraordinary numbers. But what makes raptors so special?
All birds, even those as different as a golden eagle and a hummingbird, share some common traits, such as feathers, wings, laying eggs and being warm-blooded. But certain characteristics set the group of birds called raptors apart from other birds.
The word raptor comes from the Latin rapere, which mean to seize or plunder — an apt way to describe birds that swoop down on their prey. Idaho has 31 species of raptors: 17 species of diurnal raptors (hawks, eagles, and falcons) and 14 species of nocturnal raptors (owls).
All raptors have a hooked beak, strong feet with sharp talons, keen eyesight, and a carnivorous diet.
- Hooked beak — The raptor's beak sets it apart from other birds. All raptors have the same beak design, curved at the tip with sharp cutting edges to rip and tear apart their prey. Falcons use their beak to kill their prey by severing the spinal cord.
- Sharp talons — Birds of prey have powerful leg and toe muscles that end with sharp talons. This makes their feet lethal weapons. Their feet are perfectly designed to catch, hold, and carry prey. The length and size of a raptors toes, and the curvature and thickness of its talons are related to the type of prey it pursues. Most birds of prey have three toes pointing forward and one pointing backward. These toes can apply an extremely powerful grip on their prey, literally crushing it to death. The talons may also kill the prey by piercing the soft tissue and vital organs. Osprey, like owls, have one hinged toe that can be held in a forward or back position. This allows them to hold fish with two talons on each side for a secure grip. Osprey also have spiny scales on their feet that help them hold slippery fish more securely.
- Keen eyesight — Raptors have very keen eyesight due to the relative size of the eyeball in proportion to their head, eye muscles designed for rapid focus, and the high resolution of the retina. Diurnal raptors have full color vision and two concentrations of sharp vision on the retina. This sharpest point of vision is called the fovea. When the raptor’s two fovea work in unison, they give them very accurate depth perception which aids catching moving objects. Nocturnal raptors, like owls, have an added advantage of remarkable night vision. Owls have a concentration of rods in their retina that are used to see in low light conditions. An owl's eyes are also located in the front of their heads, much like humans, giving them a larger area of binocular vision.
- Carnivorous diet — Although the diet varies from species to species, all raptors are meat eaters. Peregrine falcons feed mainly on water fowl while prairie falcons take mostly small mammals. Some species have a very strict diet like the snail kite found in Florida which eats only Pomacea, large, fresh-water snails. Great horned owls,on the other hand, are known to eat over 250 different kinds of animals.