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BC Conservation Data Centre: Species Summary


Falco mexicanus
Prairie Falcon


 
Scientific Name: Falco mexicanus Schlegel, 1851
English Name: Prairie Falcon
 
Classification / Taxonomy
Scientific Name - Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Classification Level: Species
Species Group: Vertebrate Animal
Species Code: B-PRFA
Kingdom Phylum Class Order Family
Animalia Craniata Aves Falconiformes Falconidae
   
Conservation Status / Legal Designation
Global Status: G5 (Apr 2016)
Provincial Status: S1 (Apr 2018)
BC List: Red
Provincial FRPA list: Y (Jun 2006)  
Provincial Wildlife Act:
COSEWIC Status: Not at Risk (May 1996)
SARA Schedule:
General Status Canada: 3 - Sensitive (2005)
Migratory Bird Convention Act:
   
Ecology & Life History
General Description: A medium-sized falcon with pointed wings, a hooked bill, and conspicuous (in flight) dark patches near the body on the underside of the wings (axillaries and coverts); adults are pale brown above, whitish with heavy spotting below; head has narrow dark streak extending downward from each eye; immatures are buffy below; average length 39-50 cm, wingspan 89-109 cm (NGS 1983).
Global Reproduction Comments: Laying may begin as early as February in Texas and Mexico; March in California, Washington, Arizona, and Oregon; April in Montana and Wyoming. Clutch size usually is 4-5. Incubation lasts 29-33 days, mostly by female (male brings food). Young are tended by both parents, remain at nest site 36-41 days. First breeds usually at 2 years (sometimes 1 year).
Global Ecology Comments: Annual mortality estimated at 74% in immatures, 25% in adults (see Evans 1982). Recorded nesting density: 23 pairs on 26 kilometers of cliffs in Colorado, 101 pairs in 72 kilometers along Snake River, Idaho (see Palmer 1988).

Defend relatively small areas around the nest site. These may extend 300 - 400 meters around the typical cliff nest and about 100 meters above the site (Ogden and Hornocker 1977, Harmata et al. 1978, Kaiser 1986).

Foraging areas are large, overlapping and not defended (Haak 1982, Squires 1986, Hunt 1993). Steenhof (1998) reports nesting season home ranges from six studies that ranged from 59 - 314 square kilometers.

Where nesting cliffs are suitable and continuous, will nest at higher densities than most other large North American falcons (Steenhof 1998). At higher densities, nest sites tend to be visually isolated from one another (Anderson and Squires 1997). Densities of nesting falcons ranged from 0.2 pair per kilometer of linear cliff in Montana (DuBois 1984) to 0.66 pair per km in southwestern Idaho, with some stretches of canyon in Idaho having 4.3 pair per kilometer (Steenhof 1988).

Winter home ranges are much smaller than breeding season home ranges but still averaged over 30 square kilometers in Colorado (Beauvais et al. 1992). Winter roosts may be far from winter foraging areas, much as nest sites may be far from breeding season foraging areas.

Fidelity to breeding territories is very high in some areas. Runde (1987) reports an average 88% return rate in Colorado, Wyoming, and Alberta with Alberta females returning at a very high rate (96%). Return rates in Idaho, where nest sites and mates are at high densities, were substantially lower.
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		Y /
Y /
Y /
na /
Global Migration Comments: Some birds winter in breeding range, some migrate south as far as central Mexico, and, in the mountains, some birds migrate to lower elevations. See Palmer (1988) for details.
Habitats:
(Type / Subtype / Dependence) 		Agriculture / Cultivated Field / Facultative - frequent use
Agriculture / Hedgerow / Facultative - frequent use
Agriculture / Pasture/Old Field / Facultative - frequent use
Alpine/Tundra / Tundra / Facultative - occasional use
Grassland/Shrub / Antelope-brush Steppe / Facultative - frequent use
Grassland/Shrub / Grassland / Facultative - frequent use
Grassland/Shrub / Meadow / Facultative - frequent use
Grassland/Shrub / Sagebrush Steppe / Facultative - frequent use
Rock/Sparsely Vegetated Rock / Cliff / Obligate
Global Habitat Comments: Primarily open situations, especially in mountainous areas, steppe, plains or prairies (AOU 1983). Typically nests in pot hole or well-sheltered ledge on rocky cliff or steep earth embankment, 10 to more than 100 meters above base. May nest in man-made excavations on otherwise unsuitable cliffs (Cade 1982). Vertical cliffs with rock structure overhanging the site are preferred. Nests typically are placed on south-facing aspects, with overhangs offering some protection from solar radiation. May use old nest of raven, hawk, eagle, etc. Commonly changes nest site within territory in successive years (see Palmer 1988). In Mojave Desert, remote nests had higher productivity than did nests that were closer to human activity (Boyce 1988).

During winter, falcons use a number of other habitats that are not typical of those used during the breeding season. Dryland wheat fields, irrigated winter wheat and other irrigated croplands also are used for foraging in winter (Enderson 1964, White and Roseneau 1970, Parker 1972, Beauvais et al. 1992). In all cases, large patches with low vegetation stature characterize the habitats used. Depend on Horned Larks (Enderson 1964) and grassland species in general (Schmutz et al. 1991) for prey. Early successional stages, low vegetation height and large percentages of bare ground are an inferred requirement.

The use of forested habitat during migration by some Canadian birds (Schmutz et al. 1991) appears to be rare, but use of these habitats is little studied.
Food Habits: Carnivore: Adult, Immature
Global Food Habits Comments: Primarily feeds opportunistically on mammals (especially ground squirrels), lizards, and birds, generally up to size of quail and rabbits. In southwestern Idaho, reproduction is closely linked to the abundance of the ground squirrel Spermophilus mollis. Even following a prolonged crash in ground squirrel populations, and in the absence of important alternate prey, falcons continued to seek ground squirrels (Steenhof and Kochert 1988). Had a much more specialized diet than other raptors in southwestern Idaho and variation among individuals was low (Steenhof 1998). Ground squirrel populations fluctuate with drought cycles, thus potentially affecting productivity and population trends (Van Horne et al. 1997).

In winter, often takes Horned Larks (Eremophila alpestris) on fields of winter wheat. Young may take large insects.

Usually captures prey on or near ground; rapidly pursues birds in flight (see Palmer 1988 for many details). May cache prey in vegetation, on ledge, or in small crevice or cavity; caching most common during early brood rearing.
Global Phenology:
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 50/ / 975
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: BREEDING: southeastern British Columbia, southern Alberta, southern Saskatchewan, and northern North Dakota south to Baja California, southern Arizona, southern New Mexico, western and northern Texas, Chihuahua, Coahuila, Durango, and San Luis Potosi (AOU 1983, Lanning and Hitchcock 1991, Steenhof 1998); formerly also northwestern Missouri. NON-BREEDING: from breeding range in southern Canada south to Baja California and central Mexico (AOU 1983, Steenhof 1998). Most abundant in winter in the Great Basin and the central and central-southern latitudes of the Great Plains (Root 1988).
 
Authors / Contributors
Global Information Author: HAMMERSON, G., REVISED BY S. CANNINGS
Last Updated: Mar 30, 1995
Provincial Information Author:
Last Updated:
   
References and Related Literature
Allen, G. T. 1987. Prairie falcon aerie site characteristics and aerie use in North Dakota. Condor 89: 187-190.
American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.
Boyce, D. A. 1988. Factors affecting prairie falcon fledgling productivity in the Mojave Desert, California. Pages 237-248 in Glinski et al., eds. Proc. Southwest raptor management symposium and workshop. Nat. Wildl. Fed. Sci. and Tech. Ser. No. 11.
Cade, T.J. 1982. The Falcons of the World. Cornell University Press, Ithaca, New York. 192 pp.
Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, J.M. Cooper, G.W. Kaiser, and M.C.E. McNall. 1990b. The Birds of British Columbia Vol. 2: Nonpasserines: Diurnal Birds of Prey through Woodpeckers. Royal British Columbia Museum, Victoria, BC.
Cooper, J.M. 1998. An Inventory Report on the Status of Diurnal Raptors (Ferruginous Hawk, Swainson's Hawk, Prairie Falcon, Peregrine Falcon) at Risk in the Southern Grasslands of British Columbia. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Working Rep. WR-92. 24pp.
Cooper, J.M., and S.M. Beauchesne. 2004. Status of the Prairie Falcon (Falco mexicanus) in British Columbia. B.C. Minist. Water, Land and Air Prot., Biodiversity Branch, Victoria, BC. Wildl. Bull. No. B-116.
DeLong, J. P., and K. Steenhof. 2004. Effects of management practices on grassland birds: Prairie Falcon. Northern Prairie Wildlife Research Center, Jamestown, ND. 25pp.
Demarchi, M.W. and M.D. Bently. 2005. Best Management Practices for Raptor Conservation during Urban and Rural Land Development in British Columbia. B.C. Minist. of Environ., Victoria, B.C. MoE BMP Series.
Evans, D. L. 1982. Status reports on twelve raptors. U.S. Department of the Interior, Fish and Wildlife Service, Special Scientific Report No. 238. 68 pp.
Fisher, A.K. 1893. The hawks and owls of the United States in their relation to agriculture. Washington U.S. Dept. of Agriculture Bull. no. 6. 210 pp.
Forest Practices Code. 1997. Prairie Falcon in Species and Plant Community Accounts for Identified Wildlife: Vol. 1. B.C. Minist. For. and B.C. Environ. 184pp.
Fyfe, R. W., and R. R. Olendorff. 1976. Minimizing the dangers of nesting studies to raptors and other sensitive species. Canadian Wildl. Serv. Occas. Pap. 23. 17 pp.
Haak, B.A. 1982. Foraging ecology of prairie falcons in Northern California. MS Thesis, Oregon State University, Corvallis, Oregon, USA. 64 pp.
Harmata, A. R., J. E. Durr, and H. Geduldig. 1978. Home range, activity patterns, and habitat use of Prairie Falcon nesting in the Mohave Desert. U.S. Bureau of Land Management Report, Contract YA-512-ct8-43. 89 pp.
Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.
Hooper, T.D. 1997. Status of the Prairie Falcon in the Chilcotin-Cariboo Region. British Columbia. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Working Rep. WR-85. 22pp.
Johnsgard, P. A. 1990. Hawks, eagles, and falcons of North America. Smithsonian Inst. Press, Washington, D.C. xvi + 403 pp.
Kirk, D. A., D. Hussell, and E. Dunn. 1995. Raptor population status and trends in Canada. Bird Trends (Canadian Wildlife Service) 4:2-9.
Lanning, D. V., and M. A. Hitchcock. 1991. Breeding distribution and habitat of prairie falcons in northern Mexico. Condor 93:762-765.
National Geographic Society (NGS). 1983. Field guide to the birds of North America. National Geographic Society, Washington, DC.
Olsen, P. D., R. C. Marshall, and A. Gaal. 1989. Relationships within the genus FALCO: a comparison of the electrophoretic patterns of feather proteins. Emu 89:193-203.
Palmer, R. S., ed. 1988b. Handbook of North American birds. Vol. 5. Yale Univ. Press, New Haven. 465 pp.
Pendleton, B. A. G., B. A. Millsap, K. W. Cline, and D. M. Bird. 1987. Raptor management techniques manual. National Wildlife Federation, Sci. and Tech. Ser. No. 10. 420 pp.
Root, T. 1988. Atlas of wintering North American birds: An analysis of Christmas Bird Count data. University of Chicago Press. 336 pp.
Snow, C. 1974. Habitat management series for unique or endangered species, Report No. 8, Prairie Falcon, FALCO MEXICANUS. Bureau of Land Management, U.S. Dept. of Int., Technical Note, T-N-240, Denver.
Squires, J. R., S. H. Anderson, and R. Oakleaf. 1993. Home range size and habitat-use patterns of nesting Prairie Falcons near oil developments in northeastern Wyoming. Journal of Field Ornithology 64:1-10.
Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.
United States Bureau of Land Management. 1979. Snake River birds of prey special research report to the Secretary of Interior. U.S. Bureau of Land Management, Boise, Idaho.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 1995. Species Summary: Falco mexicanus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Feb 22, 2025).