Falconiformes are a taxonomic Order under the Class of Aves. They comprise a large group of warm blooded vertebrates commonly known as the "birds of prey", which include about 225 species of hawks, and eagles. Birds of prey, as the name implies, are predatory carnivores that largely feed upon small vertebrate mostly fish, but for small birds sometimes eat small mammals.
Family Falconidae: They differ from other Falconiformes in killing with their beaks instead of their feet. They have a "tooth" on the side of their beak for the purpose.
Family Accipitridae: They are so many kinds of birds of prey in Family Accipitridae. They usually have sharp edge of wingspans, and have sharp talons.
Family Sagittariidae: They look like an eagle, but have rounded-wings and very long legs. The Secretary Bird is a member of Sagittariidae family. It is a large bird of prey, which includes many other diurnal raptors such as kites, buzzards, vultures, and harriers.
They reproduce sexually by laying eggs, usually at the age of 2~5. They lay about 2~5 eggs each year. Most Accipitriformes don't start breeding their eggs until they are at the age of five to seven years. If there are no nesting sites made, they may be forced to delay breeding. In March or earlier depending on region, they begin to lay eggs. Females lay 3–4 eggs by late April. The eggs are approximately the size of chicken eggs. The eggs generally incubate for 5 weeks. After hatching, 2-ounce chicks become fliers within eight weeks. When food is scarce, the first chicks to hatch are most likely to survive.
The order Falconiformes, known as birds of prey, eat small vertebrate mostly fish, and sometimes eat small mammals.