Falcon

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For other meanings, see falcon (disambiguation).
"Tiercel" redirects here: for other meanings, see tercel.

Falcons
Yeti, a hybrid white gyrfalcon × saker falcon
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Aves
Order:
Falconiformes
Family:
Falconidae
Genus:
Falco

Species

About 37; see text.

A Falcon is any of several species of raptors in the genus Falco. The word comes from Latin falco, related to Latin falx ("sickle") because of the shape of these birds' wings.

Overview

Adult falcons have thin tapered wings, which enable them to fly at high speed and to change direction rapidly. Younger 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 broadwing. This is to make it easier for them to fly while learning the exceptional skills required to be effective hunters in their adult configuration.

Peregrine Falcons are the fastest-moving creatures on Earth. Other falcons include the Gyrfalcon, Lanner Falcon, and the Merlin. Some small insectivorous falcons with long narrow wings are called hobbies, and some which hover while hunting for small rodents 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 (UK spelling) or tiercel (US spelling), from Latin tertius = third because of the belief that only one in three eggs hatched a male bird.[1] [2] Some sources give the etymology as deriving from the fact that a male falcon is approximately one third smaller than the female.

A falcon chick, especially one reared for falconry, that is still in its downy stage is known as an eyas[3][4] (sometimes spelt eyass). The word arose by mistaken division of Old French un niais, from Latin presumed *nidiscus ("nestling", from nidus = nest).

The technique of hunting with trained captive birds of prey is known as falconry.

In February 2005 the Canadian scientist Dr Louis Lefebvre announced a method of measuring avian intelligence in terms of their innovation in feeding habits. Falcons were named among the most intelligent birds based on this scale[citation needed].

Systematics and evolution

Compared to other birds of prey, the fossil record of the falcons is not well distributed in time. The oldest fossils tentatively assigned to this genus are from the Late Miocene, less than 10 million years ago. This coincides with a period in which many modern genera of birds became recognizable in the fossil record. The falcon lineage - probably of North American or European, possibly of African origin, given the distribution of fossil Falconidae is likely to be somewhat older however.

Falcons are roughly divisible into three groups. The first contains the kestrels (probably excepting the American Kestrel: Groombridge et al. 2002); usually small and stocky falcons of mainly brown upperside color and sometimes sexually dimorphic; three African species that are mainly grey in color 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 slaty grey in their plumage; the malar area is nearly always black. They feed mainly on smaller birds.

Last are the Peregrine Falcon and its relatives: powerful birds, often the size of small hawks, they also have a black malar area (except some very light color morphs), and often a black cap also. 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 as opposed to the other groups, where tail colour is not indicative of evolutionary relationships[1]

The tails of the large falcons are quite uniformly dark grey with rather inconspicuous black banding and small white tips. These largest Falco feed on mid-sized birds and terrestrial vertebrates, taking prey of up to 5-pound sage grouse size.

While these three groups, loosely circumscribed, are an informal arrangement, they are probably contain several distinct clades in their entirety. A study of mtDNA cytochrome b sequence data of some kestrels (Groombridge et al. 2002) 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 strike), 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 color 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 main kestrel

Common Kestrel
New Zealand Falcon, a relative of the hobbies
File:Peregrine falcon x.jpg
Peregrine Falcon

Species in taxonomic order

References

  • Groombridge, Jim J.; Jones, Carl G.; Bayes, Michelle K.; van Zyl, Anthony J.; Carrillo, José; Nichols, Richard A. & Bruford, Michael W. (2002): A molecular phylogeny of African kestrels with reference to divergence across the Indian Ocean. Molecular Phylogenetics and Evolution 25(2): 267–277. doi:10.1016/S1055-7903(02)00254-3 (HTML abstract)

Footnotes

  1. ^ For example, tail colour in the Common and Lesser Kestrels is absolutely identical, yet they do not seem too closely related (Groombridge et al. 2002). On the other hand, the Fox and Greater Kestrels can be told apart at first glance by their tail colours, but not by much else; they might be very close relatives and are probably much closer to each other than the Lesser and Common Kestrels.

External links

Wikimedia Commons has media related to Falcon.
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