BirdWatching USA – September-October 2019

amazingbirds BY ELDON GREIJ

Most eagles, hawks, and falcons are
specialized for capturing and feeding
on birds and mammals. The Bald Eagle
and Osprey prefer fish. All have a
sharply hooked beak, toes that end in
curved claws for grasping, and
exceptional vision for spotting prey.
The large, curved claws (talons), when
closed, will puncture prey and are great
for tearing f lesh. These raptorial feet
give birds of prey the name raptors.
Evolution met the birds’ visual
needs by packing the retina with huge
numbers of sensory cells (rods and
cones), ranking raptors at the top of all
birds in this trait. (The capability of
human eyes isn’t even close.)
Throughout the avian class, males are
larger than females for almost all

species. Raptors are an exception, as

almost all females are larger than

males, some markedly so, and the

reason is still not clear.

Hawk-watching season is upon us,

so I thought it would be a good time to

provide an overview of North

American raptors.

Eagles are spectacular because they

are eagles. They are huge, powerful,

and graceful, with a fierce disposition.

We have two: the Golden Eagle, which

is found worldwide in the Northern

Hemisphere, and the Bald Eagle,

restricted to the New World. Females

of both can reach 15 pounds with

7-foot wingspans. The Golden is a fast

f lyer and dives at great speeds. It

prefers medium-size birds and

mammals, while the Bald is a common

scavenger well adapted to take fish.

Osprey are grouped with the hawks

and eagles but placed in their own

family. Their wings are long and

narrow with a crook in each wing,

creating an “M-like” pattern. Osprey

are well designed for a fish diet with

long, sharp talons and a long, sharply

hooked bill. They even have small

spines (spicules) on the bottoms of

their feet to help hold slippery fish.

Because Osprey and Bald Eagles share

similar habitat, they have frequent

interactions. Osprey often drop their

fish when attacked by an eagle, and the

eagle dives to grab the fish, usually

before it hits the water.

Hawks include raptors with broad,

rounded wings. In some, called

accipiters, the wings are short, and the

birds have long tails. They feed

primarily on small birds in forested

habitats, where the powerful wings

give bursts of speed and the long

rudder-like tail provides

maneuverability as they twist through

the trees. The three accipiters in North

America are the Northern Goshawk,

the size of a large hawk; Cooper’s

Hawk, the size of a crow; and Sharp-

shinned Hawk, a little bigger than a

Blue Jay.

Buteos have large, wide wings that

are longer and wider than those of

accipiters, and their tails are short and

often fanned out. The large, broad

wings and wide tails significantly

increase lift, facilitating soaring and

slow f light, allowing the birds to find

and capture small mammals. Buteos

include small to midsize hawks, such

as Broad-winged and Red-shouldered,

as well as large hawks like Red-tailed

North America’s raptors

A primer on hawks, eagles, and their kin

RAPTORIAL: One buteo species with identifiable subspecies is Red-shouldered Hawk. The
subspecies from South Florida, shown here, is paler than its eastern and western counterparts.

Eagles are spectacular

because they are eagles.

They are huge, powerful,

and graceful.

Wil

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sto

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54 BirdWatching • September/October 2019