In more northerly and westerly areas of Britain, kestrels often migrate south at the end of the breeding season, but return the following spring to form their territories. In winter many more kestrels visit from the Netherlands and Scandinavia.
Kestrels nest on a ledge, in a tree hole or in a disused nest. Breeding begins April to may. The clutch of 3 — 6 eggs is incubated by the female and the chicks hatch after 27 — 31 days. The eggs measure around 39 millimetres by 32 millimetres.
They are smooth and non-glossy and coloured white or yellowish-buff with red-brown markings. Both adults feed the young birds, though the newly-hatched are usually fed by the female with the male hunting and bringing the food to the nest. Juveniles fledge after 27 — 39 days and disperse from their natal grounds in July — August and may travel up to miles kilometres.
Kestrels are not considered to be globally threatened and are the commonest bird of prey in Europe, although kestrels have declined in Britain in the last few years. Image Source. More Fascinating Animals to Learn About. Galapagos Willet Bird. Kestrels do not construct their own cavities, however, and thus they are secondary cavity nesters. Kestrels choose a variety of cavity types, including old woodpecker holes, squirrel nests, crevices in barns and building roofs, man-made nest boxes, or other similar structures.
American Kestrels do occasionally use old, sheltered bird nests, however this behavior is rare compared to cavity nesting. The male kestrel claims a nesting territory and identifies potential nest cavities. Males will escort potential mates to cavities within their territories and the female will choose the nest site. Females appear to select males based on their plumage, flight displays, and how ideal their claimed nesting territory and potential nest cavities appear to be.
Copulation between pairs is frequent and can occur from the time that both birds are at the nest site until the first egg is laid.
Not all copulations are fertile, but they affirm the social bond between the male and female for the duration of the nesting season.
Females will lay anywhere from 1 to 7 eggs, with being the average. One egg is typically laid every other day, and incubation begins in full after the clutch is complete. The male or female may incubate the eggs briefly during the laying period, but incubation becomes a full-time job after the female is done laying eggs entirely. The female typically performs the majority of the incubation, with the male hunting and bringing her food.
The male will assist in incubation, however, and the female can hunt for herself on occasion as well. Incubation of the eggs typically takes days.
American Kestrel nestlings are born altricial, meaning blind and helpless. Though they are covered in a fine layer of white down, the down is not sufficient for thermoregulation, so the nestlings rely on the parents to keep warm. Much like with incubation, the female performs most of the brooding, and the male provides most of the food, but the male and female will sometimes swap jobs.
The nestlings grow rapidly—their eyes opening a few days after hatching. Kestrel chicks reach their full adult body size in about 20 days of age. Their feathers are grown in enough to make their first flights around days of age. Fledglings are capable of flying or climbing up to trees or bushes within a couple hours. During this period, the adult male and female will feed and protect the young birds as they make their first forays outside of the nesting cavity.
Once kestrels have fledged, they'll remain in contact with their parents for the next few weeks before reaching independence. Groups of fledgling may join together in hunting flocks that may include young from several nests.
Populations of American Kestrels range from fully migratory to non-migratory. By late summer, some kestrel populations may be preparing to migrate to their wintering grounds. Scientists are still learning about where it is that different breeding populations migrate for winter and the routes they take to get there.
On their wintering grounds, kestrels are also territorial. Research shows that kestrels will roost that is, spend the night in nest boxes on winter nights, too! So, these boxes are actually important for more than just nesting! This charasmatic little falcon is in decline across North America and has been so since at least the s.
Breeding habits Although kestrels mature when they are a year old, many do not manage to secure a mate and a breeding territory until their second year. The kestrels year The timing of egg laying is dependent on the weather, but the female normally lays her clutch of eggs in late April or early May.
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Raptors of eastern North America. A photographic guide to North American raptors. Academic Press, San Diego, California. Bent, A. Life histories of North American birds of prey. New York: Dover. Brauning, D. Atlas of breeding birds in Pennsylvania. Pittsburgh: University of Pittsburgh Press. Brown, L. Eagles, hawks and falcons of the world. New York: McGraw-Hill. Craighead, J. Hawks, owls and wildlife. Hawk Mountain Sanctuary Association.
Nestboxes for kestrels. Johnsgard, P. Hawks, eagles and falcons of North America. Clark, W. A field guide to hawks of North America. Boston: Houghton Mifflin. San Diego: Academic Press. Dunne, P. Subscribe Shop Blog Events News. American Kestrels are the smallest and most colorful falcons in North America. What size is an American kestrel? American Kestrel Raptor Bites Belong to the family Falconidae, a group of 60 species of caracaras, falconets, pygmy falcons, forest falcons, and falcons.
Are about the size of a Blue Jay. Were once called sparrow hawks. Occur only in the New World. Because of their small size and habit of perching on utility lines, American Kestrels are often mistaken for Mourning Doves. Male American Kestrels have blue-gray wings; females have brown wings. Male and female American Kestrels can be told apart by their plumage as early as three weeks of age. Do not build their own nests, but instead nest in cavities made by other birds, and in nestboxes built by humans.
Some Kestrels migrate long distances while others do not migrate at all. In North America, male Kestrels winter farther north than do female kestrels. In winter, female Kestrels hunt in more open, less wooded areas, than do males. Hawk Mountain Sanctuary has been erecting nestboxes for Kestrels in the Kempton Valley since the early s. An American kestrel is the smallest and most colorful falcon in North America and is one of the best known, most frequently observed, and readily identifiable raptors in North America.
Kestrels are conspicuous, colorful, open-habitat birds of prey about the size of a Mourning Dove.
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