Prairie Falcon (Falco mexicanus)
Associated Species: Other species that may use habitat in a similar way and/or respond similarly
to threats, management, and conservation activities include Golden Eagle, Peregrine Falcon,
Great Horned Owl, and Common Raven.
Distribution: Prairie Falcons breed throughout the western U.S., from southern British
Columbia east to southern Saskatchewan, then in a broad band south through southern California,
Arizona, and New Mexico. In Colorado, they nest in scattered locations throughout the state,
with concentrations in Douglas County and southeastern Colorado, where they inhabit the
grassland and cliff/rock habitat types.
Habitat Requirements: These falcons breed on cliffs and rock outcrops, and hunt in adjacent
open areas such as grasslands and shrubsteppe.
Ecology: Adults arrive on the breeding grounds in February or March and initiate nesting in late
April; young fledge in June and July. Many birds that breed to the north of Colorado spend the
winters here; others winter as far south as central Mexico. Their diet during the breeding season
is a mix of passerines and small mammals. Birds wintering in Colorado prey on passerines,
especially Horned Larks.
Management Issues and Conservation Recommendations: Urbanization has encroached on
feeding territories, resulting in abandonment of traditional breeding sites. Management of feeding
territories for grazing probably has little impact on their value to falcons, provided habitat still
exists for prey species. Disturbance from recreational activities (rock climbing and hiking) can
cause nest failure. Identify nest sites; discourage development in the area and restrict
recreational activities during the nesting period.
Status and Reasons for Concern: Prairie Falcons occupy a unique habitat type (cliff/rock) in
this physiographic area. They are not adequately sampled by BBS surveys within the shortgrass
physiographic area, and data collected between 1969 and 1996 are too sparse to allow analysis of
trend data (n = 7 routes). Prairie Falcons were present on an average of 6.90% (SE = 1.23) of
the BBS routes run in Physiographic Area 36 in Colorado during 1988-1997, at an average
abundance of 0.08 (SE = 0.02) individuals per route. The mean number of routes run each year
was 29.2 (SE = 2.28). This species is monitored by MCB with a statewide census.
Biological Objective: Maintain or increase the species' distribution and abundance, based upon
results from the BBS and MCB monitoring programs.
Selected References: Andrews and Righter 1992, Beauvais et al. 1992, Kingery 1998, Steenhof