Prairie Falcon - Falco mexicanus
Sexes are similar in color, uniformly buffy brown above and creamy white below. The tail is rufous-brown with very fine barring. Adults have a brown-barred breast and belly, while juveniles have more boldly brown-streaked under-parts. Both adults and young have dark brown feathers on the undersides of the wings near the body ("wing pits"), and a dark brown stripe running diagonally backward from below the eye. The eye is dark brown. Average length 39 to 50 cm, wingspan 89 to 109 cm; males average about 15 inches in length and have a wingspan of about 37 inches in length, and females average about 17 inches in length with a wingspan of about 41 inches. 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).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Prairie Falcons are about the same size as juvenile Peregrine Falcons, but lighter in color and lack the heavy dark wedge on the side of the face of the Peregrine Falcon. They are much smaller than Gyrfalcons, and much larger and lighter in color than female Merlins. Differs from all other North American falcons in having dark patches in the wingpits.
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Observations spanning multiple months or years are excluded from time charts)
Migration southward and eastward from Montana nesting areas is common (FWP). Bozeman area: wintering birds arrive November 1 to November 15 and leave by March 25 (Skaar 1969).
Prairie Falcons use cliffs for nesting, and grassland and prairie habitats for hunting. 83% nesting territories located between 4000 and 6000 ft. Most nests are on cliffs averaging 125 ft in height. Mean height above base of cliff was 80 ft. 72% of eyries faced south or east. Almost all nests overlooked at least some grassland (Leedy 1972).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
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- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Recently Disturbed or Modified
Wetland and Riparian Systems
Prairie Falcons feed primarily on birds and mammals, often exploiting locally abundant prey populations. In Montana, common prey are Western Meadowlarks, Horned Larks, and ground squirrels. Western MT: Richardson's Ground Squirrels (Citellus ricardsonii) and Horned Larks (Eremophilia alpestris) were most common prey at eyries, with Western Meadowlarks (Stornella neglecta) next in abundance (Leedy 1972).
Nests sites are on cliffs, usually in a large hole or sheltered ledge, or sometimes in stick nests built by Golden Eagles or hawks. Adults establish nesting territories in late March or early April, and noisy aerial courtship displays are common. Clutches of three to five eggs are usually laid in late April, and incubated for about one month. Young leave the nest when about 40 days old, but may stay nearby for up to four weeks afterward. Pairing occurred April 1; completion of clutches April 10 to May 14; hatching May 9 to June 12; fledging June 15 to July 21. Mean no.'s: eggs/clutch 4.3; fledglings/success/pair 2.9; fledglings/territory 1.9; young fledged/nesting attempt 0.9 (Leedy 1972).
- Literature Cited AboveLegend: View Online Publication
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- Additional ReferencesLegend: View Online Publication
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