Falcons are closer kin to parrots than to hawks and eagles
Falcons, about forty species in the genus Falco, are built for speed: a diving peregrine has been clocked at 390 kilometres an hour. They look like hawks and eagles, yet genetically their nearest relatives are parrots and songbirds, and they kill with their beaks rather than their talons.
Adults have slim, pointed wings made for fast flight and sudden turns. First-year birds carry longer flight feathers that give them a more all-purpose wing shape, making flying easier while they learn to hunt. Falcons belong to the Falconidae along with caracaras, and they dispatch prey with a notch on the beak called a tomial tooth, whereas hawks and eagles in the unrelated Accipitridae rely on their feet. Some small, narrow-winged species are called hobbies, and those that hover while hunting are kestrels.
Sizes range from the gyrfalcon, up to 65 centimetres long, to the Seychelles kestrel at 15 to 24. Females are usually bigger than males, which lets a pair take a wider range of prey. Their eyesight is superb, with one species measured at 2.6 times human acuity, and peregrines have been recorded diving at 320 kilometres an hour, making them the fastest animals on Earth. Kestrels, usually small, stocky and brown above, eat rodents, reptiles and insects; the fox and greater kestrels are nearly identical except for their tails.
The fossil record is patchy. For years the oldest fossils assigned to the genus were under 10 million years old, from the late Miocene, but by 2021 a falconid fossil had been dated to about 55 million years. The family probably arose in North America or Africa, perhaps the Middle East or Europe. Falcons live on every continent except Antarctica, though related raptors lived there in the Eocene.
Linnaeus coined the genus in 1758, with the merlin as its type species. Falco is Late Latin, from a word for sickle, a nod to the curved claws. A male is a tercel or tiercel, from the Latin for third, either because one egg in three was thought to produce a male or because males are about a third smaller. A downy chick raised for falconry is an eyas, a word born from a mistaken split of the Old French un niais, meaning nestling.
Source: Falcon
