Hawks are a large and diverse group of predatory birds found on every continent in the world except for Antarctica. These birds hunt during the day. They use their keen eyesight, hooked beaks and sharp talons to hunt, catch and kill their prey. Hawks feed mostly on small mammals, reptiles, amphibians and other birds. There are many hawk species, which are categorized into four groups: buteos, accipiters, kites and harriers. The classifications are based on the birds’ body type and other physical features.

Buteos hawks are known for their large bodies, broad wings and stout legs. Two examples of buteos hawks are the Ferruginous hawk and the Swainson's hawk. The Ferruginous hawk is the largest of the buteos hawks and measures about 26 inches long with a wingspan of 4 to 5 feet. The Ferruginous hawk is found mostly in dry areas and the grasslands of Canada, the United States and Mexico. The Swainson's hawk measures about 22 inches in length, with a wingspan of 4 feet. This hawk is found mostly in grasslands and farmlands. It spends its summers in the western half of the United States and winters in South America.

Accipiters are not as large as buteos, yet they also share the characteristic of having rounded, broad wings. These types of hawks have long tails that help them maneuver easily through the air when hunting. Two examples of Accipiter hawks are the Cooper's hawk and the Sharp-Shinned hawk. The Cooper's hawk measures about 19 inches long and has a wingspan of up to 3 feet. This hawk often is found in the dense forests of Southern Canada and the United States, though it also migrates as far as South America. The Sharp-Shinned hawk measures about 10 to 14 inches in length and has a wingspan of about 27 inches. This hawk is commonly found in forests in the United States and the Caribbean.

Kites are known for being very graceful fliers and have long tails and long, pointed wings. These birds tend to have talons that are not as powerful as other hawks' talons and they have shorter legs. Two examples of kite hawks include the red kite and the Mississippi kite. Red kites are medium-sized hawks with long, forked tails. These birds are often found throughout Europe. The Mississippi kite is a small kite hawk measuring up to 15 inches long and weighing only about 13 ounces. This bird's wingspan reaches about 44 inches wide. The Mississippi kite is found primarily in wooded areas and grasslands of the Midwest and the eastern United States, where it feeds mostly on insects.

Harrier hawks are slender birds with long legs, tails and wings. These hawks have a distinctive facial disk, much like owls, that allows them to hear their prey better while hunting. Two example of Harrier hawks include the Northern Harrier and the Spotted Harrier. The Northern Harrier measures about 24 inches long and has a wingspan of about 4 feet. These hawks are found mostly in grasslands and wetlands of North America, Asia and Europe. The Spotted Harrier is a medium-sized hawk with a broad head and long yellow legs. This hawk is commonly found in grassy open woodland areas of Australia.