The Aplomado Falcon (Falco femoralis) is a species of raptor in the genus Falco. Falco is a group of raptors that includes about 40 species found worldwide. Members of this genus are generally high-speed birds which have sharp, pointed wings and which hunt for other bird species that they pursue and seize in flight.
Falcons all have a sharp, hooked bill used in eating. Their bill is unusual among birds of prey because they have a special adaptation for killing their prey. It is a small notch in the upper mandible of the bill that is called a tomial tooth. This notch is used to separate the cervical vertebra in the neck of their prey. 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 the falcon will begin pursuing their prey in a tail-chase that can last for several minutes.
Like many birds of prey, and particularly noticeable amongst members of the genus Falco, male and female birds are not the same size. The female bird is larger than the male. In fact, it can sometimes be as much as one-third larger.
The Aplomado Falcon has three recognized subspecies.
- F. f. femoralis is mainly found in the lowlands of South America below 1,700 meters in elevation. This is the smallest of the subspecies. It is generally more brown-colored on the back, has a darker crown, a more buff-colored line over the eye, and the bellyband is narrower (but still complete) as compared to the other subspecies.
- F. f. pichinchae is commonly found in the temperate mountains of South America above 2,300 meters. and range from Colombia to Argentina. Larger than F. f. femoralis and similar in size to F. f. septentrionalis. Back is a dark slate-gray color, the chest is more streaked, and the bellyband is incomplete.
- F. f. septentrionalis is found in Central America. Larger than F. f. femoralis and similar in size to F. f. pichinchae. back is a paler blue-gray in color and the bellyband is wide and complete.
Taxonomy at a Glance
- Domaine: Eukaryota
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Falconiformes
- Family: Falconidae
- Genus: Falco
- Species: Falco femoralis
How to Identify an Aplomado Falcon
Aplomado Falcons are slim, mid-sized, and light-bodied falcons. They have long and sharply pointed wings, a long, straight tail with a rounded tip, and a head that is relatively small compared to their body.
This species is grey on the upper parts of its body. The head has dramatic markings including a light buff line above the eye, a dark line through the eye, a light buff cheek, and a dark malar or mustache line. The tail is dark with five to six fine, white, horizontal bars. The breast and belly are white to light orange in color with a dark grey band across the belly. This belly is complete in some populations and only barely extends from the sides in others. Some individuals have fine, dark, vertical streaking on the breast and belly.
Juvenile birds are similar in plumage to adults but can be distinguished by being more brown than grey on the back and having many of the back feathers are tipped with a thin cinnamon-colored edge. Also, the grey bellyband is brown in juveniles, and the streaking on the breast and belly is more dense.
Adult males and females are similar in plumage and juvenile males and females are similar as well.
In flight, Aplomado Falcons have fast, shallow wingbeats. They fly close to the ground, especially when hunting. This falcon soars on flat wings, and often hovers while watching for prey.
Where Do Aplomado Falcons Live: Habitat
Aplomado Falcons live across a huge geographic range that stretches from southern Texas, USA to the southern tip of Chile. Across that range, they live in a wide variety of open habitats such as grasslands, savannahs, cactus deserts, wetlands, and agricultural lands. They will basically live wherever they can find food and that has scattered trees for perching. Alplomado Falcons do not seem to like dense forests.
This species is largely sedentary, though some movements up and down in altitude have been noted, especially in birds living in mountain ranges such as the Andes. Some individuals in southern Chile seem to be partially migratory, and some nomadic movements have been observed with individuals ending up on offshore islands and various areas in southeast Brazil. Elevation can range from sea level to about 4,600 meters.
Aplomado Falcon Diet and Feeding
Aplomado Falcons, as is common among members of this genus, eat mainly birds. However, their diet is also comprised of a range of other prey species. This range of other species can include bats, small rodents, small reptiles, and large insects such as butterflies and dragonflies and beetles. Some have even been observed to prey on crabs!
Aplomado Falcons have a range of foraging behaviors. They can deftly maneuver in flight when pursuing flying prey. Pairs or family groups sometimes hunt together, a behavior that is unusual in raptors, with some individuals in the group scaring prey out from cover, and other individuals of the group capturing it. Aplomado Falcons have also been observed to hunt along the active edges of grass fires, capturing prey that is displaced by the heat and flames. On occasion, Aplomado Falcons will also hunt on foot.
Aplomado Falcons also can be kleptoparasites which means that they steal prey from other species. If another bird of prey carrying prey is spotted by an Aplomado Falcon, the falcon may chase it and harass it (including diving on it) in the hopes that the other bird of prey will drop the food it is carrying. If the other bird of prey does drop its food, the Aplomado Falcon is often able to catch the falling food in the air.
After capturing a prey item, Aplomado Falcons generally carry it to a perch to remove the fur or feathers before eating it.
Male and female birds differ in size, so pairs will hunt different sizes of prey. Males are between 10% and 40% smaller than females, and so take smaller-sized prey. Females, being larger, take larger-sized prey. Females are able to take much larger prey, often hunting and eating birds larger than themselves. This dividing of prey resources means that the two birds can bring back more food to the nest. Both male and female birds do most of their hunting around dawn and dusk, an activity pattern called crepuscular.
Aplomado Falcon Breeding
Relatively little detailed data is available on Aplomado Falcon breeding timing, courtship, and territory selection. All these features are certain to vary widely across the wide geographic and latitudinal range of this species. In terms of courtship, male and female courtship behaviors can include courtship flights, loud and quiet calls, food exchanges, and visiting potential nest sites together. In terms of seasonality and timing, breeding can range from February to August in the northern part of the range in Mexico to September to January in central Argentina to beginning as late as November in southern Chile.
Aplomado Falcon pairs are non-migratory and stay together on their territories year-round, even to the point of staying within sight of each other.
Aplomado Falcon Nesting
Aplomado Falcons do not build nests themselves. Instead, this species uses the abandoned nests of other bird species such as corvids like ravens and Jays or other similarly sized birds of prey such as kites. Nests occur in a wide range of locations both natural and human-made, including on power poles, in trees, on yuccas, in or on low bushes, or even directly on the ground.
Clutches range from 1 to 4 eggs. Incubation lasts from 31 to 32 days and is conducted to some extent by both the male and female, though the female does more than the male. The male forages for prey to feed both himself and his mate.
A baby falcon is called an “eyas.” Young birds fledge from the nest about 28 to 35 days after hatching. This is usually the point when the young birds take their first flight. Young birds tend to stay within the territories of their parents for one to two months.
Aplomado Falcon Eggs
Eggs are laid in the nest. The eggs are more rounded in shape than a chicken egg, and somewhat smaller, about 1.7 to 1.9 inches in length. Their base color is white with speckling of brown to cinnamon. Speckling can be scattered or dense.
Aplomado Falcon Population
The most complete data on this species shows that Aplomado Falcons are uncommon in most of their geographic range. However, population levels do seem to be declining somewhat.
Currently, population estimates suggest that the global breeding population of Aplomado Falcons includes an estimated 200,000 individuals.
Is the Aplomado Falcon Endangered?
Yes and no. The Aplomado Falcon species covers such an extensive geographic range that they are able to resist most threats to complete extinction, so at a species level they are of low conservation concern. However, the northern population found in the southern USA and northern Mexico is declining much faster than other populations and so has been listed as federally endangered since 1986.
Much of this decline is due to destruction of habitat and the use of pesticides such as DDT. Aplomado Falcons, like a large number of other species of bird, suffered dramatic failures in breeding when pesticides and other insecticides were widely used in North America. Habitat restoration projects are starting to make more habitat available for this species, but much more work is needed. Captive rearing programs have been fairly successful, and over one thousand and five hundred captive-born Aplomado Falcons have been released into the wild.
Aplomado Falcon Habits
Despite the fact that they are not imposingly large birds, Aplomado Falcons do aggressively defend their nests and territories from other birds and mammals and are willing to attack animals significantly larger than themselves.
Aplomado Falcon Predators
Aplomano Falcons are mid-sized raptors. As such, they have numerous predators, and even more threats to their eggs and young. A wide variety of other birds of prey will kill an adult Aplomado Falcon including, but not limited to, Red-tailed Hawks and Great Horned Owls. Many birds, raptors and other species, many species of mammals, and some reptiles will raid nests to prey on eggs and young.
Aplomado Falcon Lifespan
Aplomado Falcons lifespans range in reports from eight years to twelve years, and even twenty-year-old individuals have been reported, though this is likely to be seen in captivity where birds do not have to face the threats of the wild and receive veterinary care.
Answer: Aplomado is Spanish for plum or lead-colored, and it refers to the color found on the backs, upper wings, and tail of the adults of this species.
Answer: No. While it is an unusual behavior, a few other species hunt cooperatively. The Harris Hawk is the most famous example of a cooperative hunting raptor, but several other species such as the Saker Falcon and Eleonora’s Falcon, in addition to the Aplomado Falcon, have also been observed to hunt cooperatively.
Answer: Aplomado Falcons are sensitive to disturbance. So, this means that there are two ways to help them. One is to give these birds enough space, and especially around their nests, to allow them to find food and raise their young. A safe distance is about 200 meters or more. A second is to stay quiet when you are around these birds. Noise can disturb and distract Aplomado Falcons which can make it more difficult for them to find food and make them more vulnerable to predators.
- 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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