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American Kestrel
Falco sparverius

Status: Lower risk

Population Trend: Declining.

Other Names: American Sparrowhawk, Antillean Sparrow Hawk (caribaearum), Cerchneis sparverius, Cuban Sparrow Hawk (sparverioides), Florida Sparrow Hawk (paulus), Guatemalan Sparrow Hawk (tropicalis), Hispaniolan Sparrow Hawk (dominicensis), San Lucas Sparrow Hawk (peninsularis), Sparrow Hawk.

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Falco sparverius
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Distribution: Nearctic/Neotropical. Central ALASKA east through CANADA to Newfoundland south discontinuously through MEXICO, Central America to NICARAGUA, and most of South America, except for Amazonia, from COLOMBIA and VENEZUELA south on both sides of the Andes to ARGENTINA, URUGUAY, and TIERRA DEL FUEGO; GREATER ANTILLES; locally in the southern LESSER ANTILLES south to GUADELOUPE; northern birds winter as far south as PANAMA and the West Indies. Breeding was recently confirmed in the Darién, Panama. more....

Subspecies: 17 races. F. s. sparverius : NORTH AMERICA from Alaska to Newfoundland south through southern CANADA and the UNITED STATES (except for southeast) to western MEXICO (except for coastal areas); winters south through MEXICO and Central America to PANAMA; F. s. paulus : UNITED STATES (South Carolina to Florida); F. s. peninsularis: MEXICO (southern Baja California, Sonora, Sinaloa); F. s. tropicalis: Southern MEXICO to northern HONDURAS; F. s. nicaraguensis: Mosquitia region of eastern HONDURAS and eastern NICARAGUA; F. s. sparverioides: CUBA and Isle of Pines; BAHAMAS (Inagua); F. s. dominicensis: HISPANIOLA; F. s. caribaearum: PUERTO RICO to GRENADA; F. s. brevipennis: NETHERLANDS ANTILLES (Aruba, Bonaire, Curaçao); F. s. caucae: Western COLOMBIA; F. s. aequatorialis: Northern ECUADOR; F. s. peruvianus: Southwestern ECUADOR, PERU and northern CHILE; F. s. ochraceus: Eastern COLOMBIA and northwestern VENEZUELA; F. s. isabellinus: VENEZUELA to northern BRAZIL; F. s. cearae: Northeastern BRAZIL south and west to eastern BOLIVIA; F. s. cinnamominus: Southeastern PERU, CHILE, BOLIVIA, southeastern BRAZIL, PARAGUAY, URUGUAY, and ARGENTINA south to TIERRA DEL FUEGO; F. s. fernandensis: Juan Fernandez Islands off west-central CHILE. more....

Taxonomy: Formerly placed in a separate genus, Cerchneis or Tinnunculus. It has been generally assumed that the American Kestrel is a sister species with the Common Kestrel F. tinnunculus of the Old World, but the cytochrome b data of Wink and Sauer-Gürth (2004) indicated that it forms a clade together with the Aplomado Falcon (F. femoralis) instead. This is such an unexpected finding that it requires further confirmation. Bildstein and Zalles (2005) have suggested that the insular races on Caribbean islands may have derived from "migration dosing," which occurs in areas of misdirected migration, stranding isolated individuals unable to return to their usual breeding grounds.

Movements: Partial migrant (Bildstein 2006). Large proportions of Canadian and U.S. populations migrate south in autumn, with northern populations more migratory than those breeding farther south (Smallwood and Bird 2002, Farmer and Smith 2009). Populations in middle latitudes are partially migratory, responding to local conditions, and those as far south as George and Florida (Smallwood and Bird op cit.) ande even southern Idaho (Henny and Brady 1994) are resident. A small proportion of the population migrates as far south as northern South America and the West Indies. Birds breeding on Tierra del Fuego migrate north to the South American mainland in the austral winter (Humphrey et al. 2004). The four Caribbean races are sedentary. more....

Habitat and Habits: Occurs mostly in lowlands, middle elevations, and lower montane areas, but occasionally as high as paramos in South America. Prefers open country with scattered trees, powerlines, fencerows, and other structures providing perches. Occurs commonly in towns and suburbs, especially where nest boxes are provided. In Central America, breeding kestrels occur in pine-oak woodland in the mountains and in pine savanna in the Mosquitia region of Nicaragua and Honduras. more....

Food and Feeding Behavior: Feeds mostly on large insects, but small rodents, bats, lizards, small snakes, small birds, and scorpions may constitute an important percentage of food items in some areas, especially in winter. Hunts by hovering over ground and stooping on prey, or by descending to the ground from an exposed perch, especially power poles and power lines. more....

Breeding: Nests in tree cavities, especially holes made by woodpeckers, holes in cliffs, telephone poles, fenceposts, buildings, nest boxes, or occasionally in the old nests of other raptors or corvids. The same nest site may be used in successive years. Clutch size is 4-6 eggs (2-4 in the West Indies and lower latitudes), which are white with dense light-brown and reddish-brown spots. Most of the incubation is done by the female, and the incubation period lasts 29-30 days. The male does most of the hunting, providing food to the incubating female and the nestlings. The nestling period is about 30 days. The young are dependent on the adults for several weeks after fledging. more....

Conservation: One of the most widely distributed diurnal raptor species in the Western Hemisphere. In Central and South America, its range is still expanding in some regions in response to deforestation, but in large portions of North America, populations have suffered major declines (Ruelas Inzunza 2007, Ruelas Inzunza and Smith 2008, Farmer and Smith 2009), based on migration counts, Breeding Bird Survey abundance indexes, and Christmas Bird Count data. Declines have occurred across large regions with very different ecologies and recent histories of development (Farmer et al. 2009). Causes for these declines have not yet been determined, but there are four main hypotheses, including contaminant effects, habitat loss and change (forest succession), increased predation by Cooper's Hawks, and West Nile virus. Two or more of these factors could be operating simultaneously. Categorized as a species of "Least Concern" by BirdLife International, but according to IUCN criteria (i.e., populations undergoing a decline of over 30% over 10 years), certain regional populations of American Kestrels could be classified as Vulnerable. more....

Population Estimates: Partners in Flight (Rich 2004) estimated the total Canadian and United States American Kestrel population at 4,300,000 individuals and the global population at 6,000,000 birds, based on extrapolations from Breeding Bird Survey results. It seems likely that this estimate was overly optimistic, and the recent well documented declines in parts of Canada and the United States have surely resulted in a much lower total population. The estimate of over one million American Kestrels in North America by Ferguson-Lees and Christie (2001) was non-specific and not based on actual survey data. Breeding kestrel populations are probably inherently limited by nest-site availability (Smallwood and Collopy 2009, Smallwood et al. 2009), but recent widespread population declines are apparently due to some other factor, or a combintation of factors. more....

Important References: 
Balgooyen, T.G. 1976. Behavior and ecology of the American Kestrel (Falco
  sparverius
) in the Sierra Nevada of California. University of California
  Publications in Zoology 103:1-83.
Bird, D.M., and R. Bowman (eds.). 1987. The ancestral kestrel. Raptor
  Research Reports no. 6. Raptor Research Foundation, Ind. and MacDonald
  Raptor Research Centre of McGill University, Ste. Anne de Bellevue, Quebec,
  Canada.
Bird, D.M., and R.S. Palmer. 1988. American Kestrel. Pp. 253-290 in R.S.
  Palmer (ed.), Handbook of North American birds. Vol. 5. Diurnal raptors.
  Yale University Press, New Haven, CT.
Farmer, C.J., and J.P. Smith. 2009. Migration monitoring indicates
  widespread declines of American Kestrels (Falco sparverius) in North
  America. Journal of Raptor Research 43:263-273.
Smallwood, J.A., and D.M. Bird. 2002. American Kestrel (Falco sparverius).
  In A. Poole and F. Gill (eds.), Birds of North America no. 602.
  Academy of Natural Sciences, Philadelphia, PA, and American Ornithologists'
  Union, Washington, D.C.
Smallwood, J.A., M.F. Causey, D.H. Mossop, J.R. Klucsarits, B. Robertson,
  S. Robertson, J. Mason, M.J. Maurer, R.J. Melvin, R.D. Dawson, G.R.
  Bortolotti, J.W. Parrish, Jr., T.F. Breen, and K. Boyd.
2009. Why are
  American Kestrel (Falco sparverius) population declining in North America?
  Evidence from nest-box programs. Journal of Raptor Research 43:274-282.
White, C.M. 1994. American Kestrel. P. 261 in del Hoyo, J., A. Elliott,
  and J. Sargatal (eds). Handbook of birds of the world. Vol. 2. New World
  vultures to guineafowl. Lynx Edicions, Barcelona, Spain.
Willoughby, E.J., and T.J. Cade. 1964. Breeding behavior of the American
  Kestrel. Living Bird 3:75-96.
more....

Sites of Interest:
VIREO
American Kestrel photos.
Kestreling
Contains original information and nice photos.
Xeno-canto
Vocalizations.
Aves de Rapina do Brasil
Species account with emphasis on Brazil.
American Kestrel Partnership
A response to kestrel population declines in North America which aims to unite the data-generating capacity of citizen scientists with the data-analysis expertise of professional biologists.
The Peregrine Fund American Kestrel webcam
The nest box is located on the Research Library building at the World Center for Birds of Prey in Boise, Idaho

Researchers:
Allen, Deborah
Atkinson, Eric
Bechard, Marc J.
Beers, Roy
Bildstein, Keith
Bird, David M.
Bloom, Peter
Cayo Cervantes, Biol. Luis Alberto
Davis, Kate
Enderson, James
Farmer, Chris
Fry, Michael
Galmes, Maximiliano Adrián
Goodrich, Laurie
Hamilton, Karl
Heath, Julie
Ibarra, Jose Tomas
Jaksic, Fabián
Karner, Paul H
Katzner, Todd E.
Liébana, María Soledad
Lincer, Jeff
Lisboa, Jorge
Martinez-Fernandez, Alberto
McIntyre, Carol
Mojica, Libby
Moore, Stan
Pagel, Joel (Jeep)
Rodriguez, Ramiro Ezequiel
Rodríguez Santana, Freddy
Santolo, Gary
Sarasola, José Hernán
Smith, Jeff
Steenhof, Karen
Varela, Nestor
Villamil Tamayo, Marcel
Watts, Bryan
Wiley, James

Last modified: 5/23/2012

Recommended Citation: Global Raptor Information Network. 2014. Species account: American Kestrel Falco sparverius. Downloaded from http://www.globalraptors.org on 23 Apr. 2014








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