The Prairie Falcon (Falco mexicanus) is species of raptor that is a member of the genus Falco which is a group of raptors that includes a total of about 40 species, worldwide. Members of this genus are generally very fast flying birds that have very sharply pointed wingtips and which prey on other birds which they capture in flight.
Member of this genus also have a sharp, hooked bill used in feeding. Even among birds of prey, the beaks of members of the Falco genus have a special adaptation for hunting and killing their prey.
It is a notch in the upper mandible of the beak called a tomial tooth used dislocate the vertebra of their prey and so make a swift and clean kill. Falcons often hunt either by spotting their prey from above and then diving at high speed to strike their target, or from a stationary perch from where a Falcon will begin pursuing their prey in a tail-chase that can last for several minutes.
Like many birds of prey, and particularly dramatic in the falcon genus, male and female birds are different in size with females being approximately one-third larger than males.
The Prairie Falcon is monotypical meaning it has no recognized subspecies or geographical variation. This species is very closely related to the Lagger Falcon of India and the Lanner Falcon of Africa and southern Europe.
Taxonomy at a Glance
- Domaine: Eukaryota
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Falconiformes
- Family: Falconidae
- Genus: Falco
- Species: Falco mexicanus
How to Identify a Prairie Falcon
Prairie Falcons are fairly large, but light bodied falcons. They have sharply pointed wings, a long, straight tail with a rounded tip, and a fairly blocky head.
Two of the best field marks for identification of this species are the axillary patches and the narrow malar stripe. The axillary patches are dark brown to black markings in the wingpits of a the bird where the wing meets the body.
These dark patches contrast markedly with the otherwise pale underside plumage. The narrow malar stripe is a dark brown mustache-like marking on the face that begins between the eye and the beak and forms a line down the face angling slightly backward.
Adult bird plumage on the undersides are creamy white with fine dark streaking running vertically down across the breast and belly while their uppersides are a sandy brown. Juvenile birds are of similar coloration but tend to be slightly lighter than adults. The differences between adult and juvenile plumages are subtle and difficult to assess in the field. The feet, eye-ring (of their unusually large eyes), and cere (the bare flesh at the base of the beak) are yellow on an adult bird, but are a blueish-grey on a juvenile bird.
When in flight, Prairie Falcons beat their wings in fast and shallow movements with the wing rarely lifting above the shoulder. This species soars on flat wings, and rarely hovers.
Where Do Prairie Falcons Live: Habitat
Prairie Falcons live in dry and arid habitats such as prairies, deserts, scrublands, and dry foothills of the western USA and northern Mexico. They breed on cliffs, bluffs, or occasionally on steep riverbanks.
This species wanders to the high tundra habitat occasionally in late summer and lowland pastures and even wetlands in winter. Elevation can range from sea level to about 3,700 meters, but Prairie Falcons are most commonly found between 200 and 2,000 meters.
Prairie Falcon Diet and Feeding
This species of falcon eats largely mammals (particularly during the summer months) and small to mid-sized birds, though some reptiles are occasionally also taken. Mammal prey species range form animals as small as bats to as large as rabbits. Bird prey species range from as small as sparrows to as large as ducks and geese.
This species relays on its own high speed to capture prey. Prairie Falcons often spot a potential prey at a significant distance and take flight.
They often use their speed to overtake prey while it is in the open (in the air or on the ground), overtake their prey, and capture it. They also take flight, but remain low (sometimes just a few yards above the ground) to use hills, rocky outcroppings, trees, and even large animals like cattle as cover to approach prey unseen.
Since male and female birds are significantly different in size, pairs often prey of animals of different sizes with females taking larger prey species and males taking smaller prey species.
This partitioning of prey species, the male and female of a pair are able to avoid competing with one another for prey, and so are able to bring a higher diversity of prey species and total number of prey deliveries to their young during the nesting season.
Prairie Falcon Breeding
Male and female Prairie Falcons may spend as much as a month exploring Possible nesting sites before settling on one to use in a particular year. Breeding can begin as early as February and will extend into July.
Prairie Falcon Nesting
Nests are scrapes on ledges or crevices on cliff faces that feature an overhang that helps to protect the eggs and young from the sun and rain. Preferred ledges are in the upper half of a cliff face.
The adults do not generally build nests, but instead simply scratch out a small depression in the dust, sand, and gravel that accumulates on cliff ledges. The one clutch of eggs each year are then laid in this shallow depression.
Clutches range from 2 to 6 eggs. Incubation lasts from 29 to 39 days, and is conducted almost exclusively by the female bird while the male provides her with food.
A baby falcon is called an “eyas.” Young fledge from the nest about 29 to 47 days after hatching at which point the young birds usually take their first flight. They often remain in the area of the nest cliff.
Prairie Falcon Eggs
Eggs are generally laid on the scrape or ledge. One egg is laid every other day until the clutch is complete. The eggs are similar in shape to chicken eggs, though a bit smaller, about 1.4 to 1.7 inches in length. They have abase color of creamy white to light red shell that is densely covered with speckling of brown or cinnamon or even purple.
As an adaptation to the dry climate that these birds live in, Prairie Falcon eggshells are less porous than most other species of raptor which helps to reduce water loss from the egg that is needed by the growing chick.
Prairie Falcon Population
According to the North American Breeding Bird Survey, Prairie Falcon population numbers are generally stable in recent decades though Prairie Falcon populations seem to cycle and be tied to cycles of prey species such as ground squirrels.
The most accurate populations estimates that are made from annual breeding bird surveys, migration counts across the western USA, and Christmas Bird Counts. The nation-wide breeding population is estimated to be about 13,000 individuals.
Is the Prairie Falcon Endangered?
This species is overall of low conservation concern due to the relatively stable population numbers that have been measured over the past several decades.
However, humans are a significant threat in several forms. Falconers take approximately 0.2% of the young produced each year. Illegal shooting of Prairie Falcons is not uncommon, especially near nest sites. Collisions with fences fairly common occurrences as are collisions with other stationary, and sometimes moving, human-made objects.
Prairie Falcons, like so many other species of bird, suffered extensive breeding failure when the pesticide DDT and other insecticides were in wide use in North America.
Prairie Falcon Habits
Prairie Falcons are notably aggressive birds. They fiercely defend their nest against all intruders including other Prairie Falcons, other species of birds including other birds of prey, and humans.
They also hunt very aggressively and are able to kill prey much larger than themselves. This is one reason this species is popular with falconers who value the hunting abilities of this species. Prairie Falcons are also incredibly agile in flight which allows them to precisely maneuver and successfully capture other agile and fast-flying birds such as swallows.
Prairie Falcon Predators
Prairie Falcons are very aggressive and as such have very few natural predators. Only large and aggressive birds of prey are capable of killing an adult Prairie Falcon such as Great Horned Owls and Golden Eagles have been know to sometimes kill Prairie Falcons.
Prairie Falcons are popular birds for use in falconry. This has lead to extensive removal of young wild Prairie Falcons from nests. However, in recent years a growing population of captive bred Prairie Falcons has emerged that is now able to supply falconers with birds and so reduce the pressure on the wild population.
Also, laws have been passed and treaties ratified in and between various countries such as the Endangered Species Act in the USA and the Migratory Bird Treaty Act between Canada, the USA, and Mexico that have the specific goal of protecting many different bird species, including the Prairie Falcon.
Prairie Falcon Lifespan
Prairie Falcons tend to live an average of about three years in the wild, though juvenile mortality is high with approximately 75% of young birds dying in their first year. Rarely, individuals can live up to twenty years.
Answer: Prairie Falcons and Peregrine Falcons are two species of large falcon, and in areas where the ranges of these birds overlap some confusion can arise when identifying these birds, especially with juveniles.
But there are differences which can be used to distinguish between individuals of these two species. The following list is not exhaustive as other differences do exist, but these are some of the most useful and observable.
• Underwing Markings: the undersides of a Prairie Falcon’s wing in both adults and juveniles are a very light colored creamy white with only scattered and fine dark streaking except for the axillaries under the base of the wing which is dark brown. This dark wingpit contrasts strongly with the rest of the underwing. Peregrine Falcon underwings in both adult and juvenile birds are much more heavily and consistently marked and so are darker and lack any contrasting areas.
• Head: Prairie Falcons, both adult and juvenile birds, have light colored heads with a light brown incomplete helmet broken by a white line over the eye and other white markings on the cheeks. They also have the narrow malar stripe discussed above. Peregrine Falcons, both adult and juvenile birds, have a full, heavy, and dark helmet with a wide malar stripe.
• Coloration: Prairie Falcons have a light sandy-brown back in both the adult and juvenile plumages. Adult Peregrine Falcons have a blue-grey back in their adult plumage, however the juvenile has a brown back similar, though generally darker than, the back of a Prairie Falcon.
• Breast and Belly Patterning: The breast and belly of a Prairie Falcon in both adult and juvenile plumages are creamy white with lightly scattered and fine dark streaks. The adult Peregrine Falcon as a clear area of white on the upper breast and fine black horizontal barring on the lower breast and belly. The juvenile Peregrine Falcon is more similar to the Prairie Falcon in that it has dark streaking on the breast and belly, but the Peregrine’s streaks are much thicker and more dense making the underside of the Peregrine Falcon much darker than that of the Prairie Falcon.
Answer: Realistically, no. Prairie Falcon males and females are different in size, but that is often difficult to observe in the field, particularly if only one bird is present. The plumage of the male and female birds does not differ, and so they cannot reliably be distinguished.
Answer: Prairie Falcons are very aggressive predators. Ducks and pheasants are on the large side of what they can commonly hunt. But big female Prairie Falcons have been know to take down Canada Geese which are about four times bigger than they themselves are, and represent the largest animals that a Prairie Falcon has been observed to hunt.
- Ferguson-Lees, J. and D. A. Christie. (2001). Raptors of the World. Houghton Mifflin Company, New York, NY, USA.
- Johnsgard, P. A. (1990). Hawks, eagles, and falcons of North America. Smithsonian Institution Press, Washington D.C., USA.
- Pyle, P. (1957). Identification Guide to North American Birds : a Compendium of Information on Identifying, Ageing, and Sexing “near-Passerines” and Passerines in the Hand. Slate Creek Press, Bolinas, CA, USA.
- Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
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