Kestrel

Kestrel (Fr. Cresserelle or Créçerelle, O. Fr. Quercerelle and Quercelle, in Burgundy Cristel), the English name1 for one of the smaller falcons. This bird, though in the form of its bill and length of its wings one of the true falcons, and by many ornithologists placed among them under its Linnaean name of Falco tinnunculus, is by others referred to a distinct genus Tinnunculus as T. alaudarius—the last being an epithet wholly inappropriate. We have here a case in which the propriety of the custom which requires the establishment of a genus on structural characters may seem open to question. The differences of structure which separate Tinnunculus from Falco are of the slightest, and, if insisted upon, must lead to including in the former birds which obviously differ from kestrels in all but a few characters arbitrarily chosen; and yet, if structural characters be set aside, the kestrels form an assemblage readily distinguishable by several peculiarities from all other Falconidae, and an assemblage separable from the true Falcons of the genus Falco, with its subsidiary groups Aesalon, Hypotriorchis, and the rest (see Falcon). Scarcely any one outside the walls of an ornithological museum or library would doubt for a moment whether any bird shown to him was a kestrel or not; and Gurney has stated his belief (Ibis, 1881, p. 277) that the aggregation of species placed by Bowdler Sharpe (Cat. Birds Brit. Mus. i. 423-448) under the generic designation of Cerchneis (which should properly be Tinnunculus) includes “three natural groups sufficiently distinct to be treated as at least separate subgenera, bearing the name of Dissodectes, Tinnunculus and Erythropus.” Of these the first and last are not kestrels, but are perhaps rather related to the hobbies (Hypotriorchis).

The ordinary kestrel of Europe, Falco tinnunculus or Tinnunculus alaudarius, is by far the commonest bird of prey in the British Islands. It is almost entirely a summer migrant, coming from the south in early spring and departing in autumn, though examples (which are nearly always found to be birds of the year) occasionally occur in winter, some arriving on the eastern coast in autumn. It is most often observed while hanging in the air for a minute or two in the same spot, by means of short and rapid beats of its wings, as, with head pointing to windward and expanded tail, it is looking out for prey—which consists chiefly of mice, but it will at times take a small bird, and the remains of frogs, insects and even earthworms have been found in its crop. It generally breeds in the deserted nest of a crow or pie, but frequently in rocks, ruins, or even in hollow trees—laying four or five eggs, mottled all over with dark brownish-red, sometimes tinged with orange and at other times with purple. Though it may occasionally snatch up a young partridge or pheasant, the kestrel is the most harmless bird of prey, if it be not, from its destruction of mice and cockchafers, a beneficial species. Its range extends over nearly the whole of Europe from 68° N. lat., and the greater part of Asia—though the form which inhabits Japan and is abundant in north-eastern China has been by some writers deemed distinct and called T. japonicus—it is also found over a great part of Africa, being, however, unknown beyond Guinea on the west and Mombasa on the east coast (Ibis, 1881, p. 457). The southern countries of Europe have also another and smaller species of kestrel, T. tinnunculoides (the T. cenchris and T. naumanni of some writers), which is widely spread in Africa and Asia, though specimens from India and China are distinguished as T. pekinensis.

Three other species are found in Africa—T. rupicola, T. rupicoloides and T. alopex—the first a common bird in the Cape, while the others occur in the interior. Some of the islands of the Ethiopian region have peculiar species of kestrel, as the T. newtoni of Madagascar, T. punctatus of Mauritius and T. gracilis of the Seychelles; while, on the opposite side, the kestrel of the Cape Verde Islands has been separated as T. neglectus.

The T. sparverius, commonly known in Canada and the United States as the “sparrow-hawk,” is a beautiful little bird. Various attempts have been made to recognize several species, more or less in accordance with locality, but the majority of ornithologists seem unable to accept the distinctions which have been elaborated chiefly by Bowdler Sharpe in his Catalogue and R. Ridgway (North American Birds, iii. 150-175), the former of whom recognizes six species, while the latter admits but three—T. sparverius, T. leucophrys and T. sparverioides—with five geographical races of the first, viz. the typical T. sparverius from the continent of North America except the coast of the Gulf of Mexico; T. australis from the continent of South America except the North Atlantic and Caribbean coasts; T. isabellinus, inhabiting continental America from Florida to Fr. Guiana; T. dominicensis from the Lesser Antilles as far northwards as St Thomas; and lastly T. cinnamominus from Chile and western Brazil. T. leucophrys is said to be from Haiti and Cuba; and T. sparverioides peculiar to Cuba only. This last has been generally allowed to be a good species, though Dr Gundlach, the best authority on the birds of that island, in his Contribucion á la Ornitologia Cubana (1876), will not allow its validity. More recently it was found (Ibis, 1881, pp. 547-564) that T. australis and T. cinnamominus cannot be separated, that Ridgway’s T. leucophrys should properly be called T. dominicensis, and his T. dominicensis T. antillarum; while Ridgway has recorded the supposed occurrence of T. sparverioides in Florida. Of other kestrels T. moluccensis is widely spread throughout the islands of the Malay Archipelago, while T. cenchroides seems to inhabit the whole of Australia, and has occurred in Tasmania (Proc. Roy. Soc. Tasmania, 1875, pp. 7, 8). No kestrel is found in New Zealand, but an approach to the form is made by the very peculiar Hieracidea (or Harpe) novae-zelandiae (of which a second race or species has been described, H. brunnea or H. ferox), the “sparrow-hawk,” “quail-hawk” and “bush-hawk” of the colonists—a bird of much higher courage than any kestrel, and perhaps exhibiting the more generalized and ancestral type from which both kestrels and falcons may have descended.