What Do You Know About Falcons?
The genus Falco, a
family of raptors, has over 40 species of falcons. Falcons are extensively
distributed across all continents of the world, with the exception of
Antarctica, where closely similar raptors did exist in the Eocene.
Adult falcons'
slender, tapering wings enable them to fly swiftly and change direction. In
their first year of flight, fledgling falcons have longer flight feathers,
giving them a shape more akin to a general-purpose bird with a broad wing. This
makes flying simpler while acquiring the outstanding abilities necessary to
become a successful hunter as an adult.
The Falconinae subfamily of the Falconidae, which also includes another subfamily that comprises caracaras and a few other species, has the largest genus of falcons. As opposed to hawks, eagles, and other raptors in the Accipitridae, which use their feet to kill, all of these birds utilize their beaks and a tomial"tooth" on the side of their beaks.
The gyrfalcon,
which may grow up to 65 centimeters in length, is the largest falcon. The Pygmy
falcon, which is the smallest species, is only 20 cm in length. The females of
falcons, like those of hawks and owls, are often larger than the males,
allowing them to hunt a wider variety of prey species.
Hobbies are little
falcons with long, thin wings, whereas kestrels are falcons that hover while
hunting.
Falcons, like many
other birds of prey, have a remarkable vision; one species' visual acuity has
been estimated to be 2.6 times that of an average person. The fastest
documented dive reached a vertical speed of 390 km/h, making peregrine falcons
the fastest-moving animals on Earth. They have been observed diving at speeds
of up to 320 km/h (200 mph).
Generally speaking, there are three or four groups of falcons. Three African species that are typically gray in color stand out from the regular members of this group. Kestrels are small, stocky falcons that typically have an upper side that is primarily brown in color and are occasionally sexually dimorphic. Kestrels mostly consume suitable-sized terrestrial animals and invertebrates, like rodents, reptiles, and insects.
The second group
includes relatives, hobbies, and slightly larger species. These birds have
a lot of dark slate-gray in their plumage, and their malar regions are almost
invariably black. They mostly eat smaller birds for food.
The peregrine
falcon and its relatives come in third place. These powerful, variable-sized
birds also have a black malar region and frequently a black cap. They fly at a
top speed of 390 kilometers per hour, making them extremely fast birds. They
differ from the other categories in that they are mostly medium grey with
lighter or brownish colors on their upper sides. If the hierofalcons are
excluded, this group typically contains species with horizontal barring on
their undersides. They are, on average, more delicately marked than hobbies.
However, the fox
and larger kestrels may only be identified at first glance by the color of
their tails and are likely far more closely related to one another than the
lesser and common kestrels. This contrasts with the other groups, where tail
color varies much generally but little according to evolutionary relatedness.
Although this is likely plesiomorphic, the huge falcons' tails are rather
evenly dark grey with hardly perceptible black striping and short, white tips.
These huge species of falcons eat terrestrial vertebrates and medium-sized
birds.
The few species of
hierofalcons are very similar to these and are occasionally grouped therein.
They represent taxa having, typically, more phaeomelanins, which give colors
like reddish or brown, and typically more heavily patterned plumage resembling
hawks. They have a pattern of blotches, lines, or arrowhead marks running
lengthwise on their undersides.
Even though this
informal grouping of three or four groups with loose boundaries likely includes
multiple different clades as a whole.
More difficult to
understand are the phylogeny and boundaries of the peregrine and hobby groups.
Only a few species have undergone molecular investigation, and the
morphologically confusing taxa are frequently understudied. In the current
genus, the morphology of the syrinx, which is useful for resolving the
phylogeny of the Falconidae as a whole, is not highly instructive. However, a
core group that includes the peregrine and Barbary falcons is confirmed to be
monophyletic as suspected, together with at least most of the
"conventional" hobbies and the hierofalcons and the more distant
prairie falcon.
The first most successful
evolutionary radiation appears to have been a Holarctic one that originated
possibly around middle Eurasia or in (northern) Africa, as the American falcon
species of today belong to the peregrine group or are evidently more primitive
species. By the Early Pliocene, at the earliest, one or more lineages were
extant in North America.
