The Falcon

Dec 08, 2013 Features / Columnists, Interesting Creatures in Guyana

---

A falcon is any one of 37 species of raptor in the genus Falco, widely distributed on all continents of the world. Adult falcons have thin tapered wings, which enable them to fly at high speed and to change direction rapidly.
Fledgling falcons, in their first year of flying, have longer flight feathers, which makes their configuration more like that of a general-purpose bird such as a broad wing. This makes it easier to fly while learning the exceptional skills required to be effective hunters as adults.
Peregrine Falcons have been recorded diving at speeds of 200 miles per hour (320 km/h), making them the fastest-moving creatures on Earth. Other falcons include the Gyrfalcon, Lanner Falcon, and the Merlin.
Some small falcons with long narrow wings are called hobbies, and some which hover while hunting are called kestrels. The falcons are part of the family Falconidae, which also includes the caracaras, Laughing Falcon, forest falcons, and falconets.
The traditional term for a male falcon is tercel (British spelling) or tierce (American spelling), from Latin tertius = third because of the belief that only one in three eggs hatched a male bird.
As is the case with many birds of prey, falcons have exceptional powers of vision; the visual acuity of one species has been measured at 2.6 times that of a normal human. In February 2005, the Canadian ornithologist Louis Lefebvre announced a method of measuring avian intelligence in terms of a bird’s innovation in feeding habits. The falcon and corvids scored highest on this scale.
Falcons are roughly divisible into three or four groups. The first contains the kestrels (probably excepting the American Kestrel); usually small and stocky falcons of mainly brown upper side colour and sometimes sexually dimorphic; three African species that are generally grey in colour stand apart from the typical members of this group. Kestrels feed chiefly on terrestrial vertebrates and invertebrates of appropriate size, such as rodents, reptiles, or insects.
The second group contains slightly larger (on average) and more elegant species, the hobbies and relatives. These birds are characterized by considerable amounts of dark slate-grey in their plumage; the malar area is nearly always black. They feed mainly on smaller birds.
Third are the Peregrine Falcon and its relatives: variably sized powerful birds that also have a black malar area (except some very light colour morphs), and often a black cap as well. Otherwise, they are somewhat intermediate between the other groups, being chiefly medium grey with some lighter or brownish colours on the upper side.
They are, on average, more delicately patterned than the hobbies and, if the hierofalcons are excluded, this group typically contains species with horizontal barring on the underside. As opposed to the other groups, where tail colour varies much in general but little according to evolutionary relatedness, the tails of the large falcons are quite uniformly dark grey with rather inconspicuous black banding and small white tips, though this is probably plesiomorphic. These large Falco feed on mid-sized birds and terrestrial vertebrates.
Very similar to these, and sometimes included therein, are the four or so species of hierofalcons (literally, “hawk-falcons”). They represent taxa with, usually, morephaeomelanins, which impart reddish or brown colours, and generally more strongly patterned plumage reminiscent of hawks.
Notably, their undersides have a lengthwise pattern of blotches, lines or arrowhead marks. While these three or four groups, loosely circumscribed, are an informal arrangement, they probably contain several distinct clades in their entirety.
A study of mtDNA cytochrome b sequence data of some kestrels identified a clade containing the Common Kestrel and related “malar-striped” species, to the exclusion of such taxa as the Greater Kestrel (which lacks a malar stripe), the Lesser Kestrel (which is very similar to the Common but also has no malar stripe), and the American Kestrel.
The latter species has a malar stripe, but its colour pattern–apart from the brownish back–and notably also the black feathers behind the ear, which never occur in the true kestrels, are more reminiscent of some hobbies. The malar-striped kestrels apparently split from their relatives in the Gelasian, roughly 2.5-2 mya, and are apparently of tropical East African origin. The entire “true kestrel” group—excluding the American species—is probably a distinct and quite young clade, as also suggested by their numerous apomorphies.
(Souce: Wikipedia – The Free Online Encyclopedia)

 

---

---