Bird of the Month: Prairie Falcon
Written by Andy McCormick
Andy McCormick, Volunteer and Former Board President of Eastside Audubon
An agile and aggressive hunter, the Prairie Falcon evolved in the arid environment of the interior west of North America.
About the same size as the Peregrine Falcon (F. peregrinus), the Prairie Falcon is sleeker, carries less weight, and has slightly more narrow and less pointed wings. These attributes combined with its longer tail offer the Prairie Falcon great maneuverability during attacks, which are usually long, low approaches close to and matching the contour of the land.
The Prairie Falcon is capable of matching the Peregrine’s speed in level flight and approaches its acceleration during a stoop (Steenhof). It relies on this speed to catch prey by surprise or quickly capture prey in a tail chase. As it attacks, the Prairie Falcon will most often rake its prey with open talons which close upon impact. At other times, it can use a closed foot. The force of this blow can create a sound which can carry 100 feet and it alone may be enough to kill the prey (Wikipedia). Photos, and audio and video recordings of the Prairie Falcon can be viewed at The Macaulay Library.
GROUND SQUIRREL SPECIALIST
The most common prey for a Prairie Falcon is any species of ground squirrel, but depending on the location, other small rodents, lizards, and swallows and shorebirds can be taken. In winter, Prairie Falcons raid flocks of Horned Larks and meadowlarks.
The Prairie Falcon is the only North American native of the genus Falco, Latin for falcon. European scientists first found the Prairie Falcon in Mexico, where it still resides, and the species epithet mexicanus was used to name it for that location. The English name refers to its preference for the prairie habitat it prefers for foraging. (Steenhof).
Prairie Falcon
Scientific Name: Falco mexicanus
Length: 17”
Wingspan: 40”
Weight: 1.6lb (720 g)
AOU Alpha Code: PRFA
PREFERS CLIFFS IN DRY COUNTRY
The Prairie Falcon is a bird of dry, open grassland or shrub-steppe country marked by cliffs, buttes, or bluffs which provide suitable nesting locations. Nest sites are usually limited to the ledge of a cliff or the recessed part of a rock under an overhang. However, they may also use an abandoned raven or hawk nest. They often inhabit territory that is also occupied by Golden Eagles.
The nest site consists only of a scrape in the dirt on the ledge. Usually, three to five eggs are deposited, and the female incubates them for about a month. The male brings food to the nest during this period and will take over incubation while the female eats. Once the eggs hatch, the male continues to bring food to both the female and fledglings for another month or until the young leave the nest (Kaufman).
STATUS AND DISTRIBUTION
The Prairie Falcon occupies the arid habitat in the interior west of North America from southern British Columbia through the intermountain west into Mexico. It is widespread over this range which expands slightly in winter as birds fly farther in search of prey. Some of the highest densities of Prairie Falcons are found in the Morley Nelson Snake River Birds of Prey National Conservation Area in southwestern Idaho. The U.S. Congress established this protected area in 1993.
The population of the Prairie Falcon is stable and fluctuates between 5,000 and 6,000 individuals (Steenhof). Nevertheless, this falcon is potentially vulnerable to human activity. Land use conversion of grassland to agriculture can destroy ground squirrel habitat. Nest sites are limited and nonrenewable, and a pair of falcons cannot easily move to other undisturbed areas if their foraging area is destroyed (Steenhof). The Prairie Falcon is also a favorite among falconers and 19 states allow nestlings to be taken for falconry training. Some management strategies have been introduced to help maintain and enhance nest sites, provide for more prey, and protect the areas from humans.
Photo credit by Wendy Miller. References available upon request from amccormick@eastsideaudubon.org.