Northern aplomado falcons live in open habitats with shrubs or trees for nesting. These habitats include desert and coastal grasslands, savannas, shrub-steppe habitats and open pastures. Because northern aplomado falcons do not construct their own nests but rely on nests constructed by stick nest builders, they require a healthy stick nest builder community for their nesting habitat.

The diet of northern aplomado falcons includes a wide array of birds (largely migratory), insects, mammals, and reptiles. Hunting methods include aerial prey capture of birds and insects but also include chasing prey and capturing it on the ground. Pairs often hunt cooperatively, especially when chasing birds. 

Adult northern aplomado falcons usually occur in pairs. In the U.S., they are primarily non-migratory, with mated pairs remaining together year-round within the same territory. They hunt and feed together and perch near each other throughout the year, not just during the breeding season. Breeding pairs tend to return to the same nesting location each year. Breeding adult northern aplomado falcons generally use smaller home ranges than nonbreeding northern aplomado falcons.

The northern aplomado falcon is a colorful, medium-sized raptor that is larger than a kestrel, but smaller than a peregrine falcon. It flies swiftly with deep rapid wingbeats, but also utilizes slow flapping, gliding or hovering flight.

The subspecies measures a total length of 15 to 17 inches (38 to 43 centimeters) and weighs between about one-half to one pound (208 to 500 grams). Its wingspan is approximately 3 feet (0.9 meters).

The upperparts of adults are described as slate to bluish grey or leaden colored, as the Spanish name for “aplomado” means “lead colored.” The head has a black-and-white striped pattern, and its underparts are tri-colored, with a whitish to buffy colored upper breast and a blackish “belly band” separating a cinnamon belly and undertail coverts. The tail is banded with a black-and-white pattern. In flight, the upperparts appear dark with a silver trailing edge on the wings. 

Females are slightly larger and heavier than males. Juveniles are more brownish than adults. At hatching, chicks are white and helpless and at 1 to 2 weeks old will molt into a grayish-dusky second natal down. At 2 to 6 weeks of age, they attain a juvenile plumage.

Eggs are whitish or buffy in color with light to dark brown or rusty colored spots and blotches. They are smooth and considered short elliptical in shape. Dimensions are approximately 1.7 inches (43 to 44 millimeters) in length and 1.3 inches (34 millimeters) in breadth.

The northern aplomado falcon has five life stages: egg (about 32 days to hatching), nestling (hatch to fledging at approximately 5 weeks), fledgling (approximately 5 weeks to 4 months), juvenile (4 months to about 1 year), subadult (1 to 2 years) and adult (over 2 years of age). 

In the wild, the life span and adult survival rate for northern aplomado falcon is not known with high certainty. The relatively high adult survival in a reintroduced population suggests the northern aplomado falcon may have a “slow” life-history strategy. In captivity, male northern aplomado falcons have lived to an estimated 24 years of age, and one female lived to 20 years. In the wild, survival to a minimum of 6 to 12 years of age has been documented through recaptures.

Northern aplomado falcons reach sexual maturity at the end of their first year but generally do not form a pair bond until the spring of their second year. Female productivity has been observed through approximately 10 years of age. Courtship is characterized by display soaring and flying, courtship feeding, and nest displays. The subspecies is presumed to be monogamous and, once paired, remains together year-round and hunts cooperatively. 

Primary nesting occurs from February through June in northern portions of the range. Females incubate the eggs, although males will occasionally share this activity. Males frequently hunt alone, especially during incubation, with females occasionally participating in hunting.