12-1-2017 ALBUFERA, VALENCIA - EURASIAN KESTREL (Falco tinnunculus)

The common kestrel (Falco tinnunculus) is a bird of prey species belonging to the kestrel group of the falcon family Falconidae. It is also known as the European kestrel, Eurasian kestrel, or Old World kestrel. In the United Kingdom, where no other kestrel species commonly occurs, it is generally just called "kestrel".

This species occurs over a large range. It is widespread in Europe, Asia, and Africa, as well as occasionally reaching the east coast of North America. It has colonized a few oceanic islands, but vagrant individuals are generally rare; in the whole of Micronesia for example, the species was only recorded twice each on Guam and Saipan in the Marianas.

The common kestrel was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under the current binomial name Falco tinnunculus. Linnaeus specified the type location as Europe but restricted this to Sweden in 1761. The genus name is Late Latin from falx, falcis, a sickle, referencing the claws of the bird. The species name tinnunculus is Latin for "kestrel" from "tinnulus", "shrill". The Latin name tinnunculus had been used by the Swiss naturalist Conrad Gessner in 1555. The word "kestrel" is derived from the French crécerelle which is diminutive for crécelle, which also referred to a bell used by lepers. The word is earlier spelt 'c/kastrel', and is evidenced from the 15th century. The kestrel was once used to drive and keep away pigeons. Archaic names for the kestrel include windhover and windfucker, due to its habit of beating the wind (hovering in air).

This species is part of a clade that contains the kestrel species with black malar stripes, a feature which apparently was not present in the most ancestral kestrels. They seem to have radiated in the Gelasian (Late Pliocene,ably starting in tropical East Africa, as indicated by mtDNA cytochrome b sequence data analysis and considerations of biogeography. A molecular phylogenetic study published in 2015 found that the common kestrel's closest relatives were the spotted kestrel Falco moluccensis and the Nankeen kestrel Falco cenchroides.

The common kestrel is diurnal and can be sedentary or migratory, depending on the region. It is known for its characteristic hunting behavior, hovering 10-20 meters above the ground before diving steeply onto prey. It is also capable of seeing ultraviolet light, which aids in detecting the urine trails of small mammals.

Breeding occurs in spring or the start of the dry season, with the kestrel preferring cavity nests in cliffs, trees, or buildings. Clutches typically consist of 3-7 eggs, which are incubated by both parents. The young fledge after 4-5 weeks and stay with the family for a short period thereafter.

The lesser kestrel and American kestrel are similar but not closely related. The lesser kestrel lacks black on the upperside except for wing and tail tips, while the American kestrel has much grey in the wings of males.

The common kestrel's diet consists almost exclusively of mouse-sized mammals, such as voles, shrews, and true mice. It may also consume small birds, particularly during the summer when fledglings are abundant. Invertebrates and arthropods can be significant food sources seasonally.

The IUCN lists the common kestrel as Least Concern. Its population has fluctuated but remains generally stable, with an estimated 1-2 million pairs globally. Some subspecies, such as those in the Canary Islands, are rarer and number less than 1000 adult birds.