- 17.7–23.6 in
- 22–24 in
- 5.1–7.4 oz
- Larger than a jay but smaller than a raven.
- Historical records of the American West indicate that Black-billed Magpies have been associates of people for a long time. Magpies frequently followed hunting parties of Plains Indians and fed on leftovers from bison kills. On their expedition, Lewis and Clark reported magpies boldly entering their tents to steal food.
- Like most members of the jay family, the Black-billed Magpie is a nest predator, although eggs and nestlings make up only a tiny portion of the bird’s overall diet.
- The Black-billed Magpie makes a very large nest that can take up to 40 days to construct. It's a lot of work, but a study found that it only used about 1% of the daily energy expenditure of the pair. Laying eggs, on the other hand, takes 23% of the female's daily energy budget.
- The Black-billed Magpie frequently picks ticks from the backs of large mammals, such as deer and moose. The magpie eats the ticks or hides some for later use, as members of the crow and jay family often do with excess food. Most of the ticks, however, are cached alive and unharmed, and may live to reproduce later.
- The longest-living Black-billed Magpie on record was at least 9 years, 4 months old and lived in Idaho.
Black-billed Magpies live among the meadows, grasslands, and sagebrush plains of the West. Their nesting territories often follow stream courses. Though they like open areas and are not found in dense woods, they stay close to cover for protection from raptors. Magpies don’t avoid human development, often spending time near barnyards, livestock areas, and grain elevators where they have ready access to food.
Like other corvids (members of the jay and crow family), Black-billed Magpies have a wide-ranging diet. They eat wild fruit and grain, as well as grasshoppers and beetles that they find while foraging on the ground (they sometimes find beetles by flipping cow dung). They also kill small mammals such as squirrels and voles, and raid birds’ nests. Carrion is also a main food source, as are the fly maggots found in carrion. Sometimes they steal meat from the kills of coyotes and foxes. Magpies also land atop large animals, such as cows or moose, and pick ticks off them. When they find an abundant food source, magpies will cache food for short periods.
- Clutch Size
- 1–9 eggs
- Number of Broods
- 1 broods
- Egg Length
- 1.2–1.5 in
- Egg Width
- 0.8–1 in
- Incubation Period
- 16–19 days
- Nestling Period
- 24–30 days
- Egg Description
- Tan or olive-brown with variable amount of dark brown speckles
- Condition at Hatching
- Helpless and naked with pink skin. Eyes are closed for the first 7 days.
Black-billed Magpie pairs share the work of building their domed nests, which vary widely in size but are typically about 30 inches high and 20 inches wide. The male gathers sticks for the exterior. The female tends to the interior, forming a mud cup and lining it with grass.
Both sexes seem to choose a nesting site together (though sometimes they disagree and each begin building separate nests in different locations). They build their dome nests in conifer trees, deciduous trees, shrubs, utility poles, and even in deserted buildings. They will nest in open woodlands, riparian thickets, farm fields, and suburban areas.
On the wing, Black-billed Magpies make long, sweeping flights with white flashes of their wing patches and long, trailing tails. They perch at the tops of trees, which is a means of visually establishing their territory, the equivalent of other bird species’ songs. Magpies walk with a swaggering strut. They sometimes gather in flocks, even seemingly living communally, and will band together to mob a raptor. In groups, males establish dominance through a stretch display: raising the bill in the air and flashing their white eyelids. They also show aggression with their wings, flickering or quivering them to display the white wing patches; and tails spreading, quivering, or flicking their elongated tail feathers. During courtship they also use a tail-spreading display. Black-billed Magpies mate for life. The female initiates the pair bond by begging for food from the male, which begins courtship feeding. During breeding, the male stands guard near the female to reduce the chance she’ll mate with another male (which does occur). One of the most notable Black-billed Magpie behaviors is the so-called “funeral”—when one magpie discovers a dead magpie, it begins calling loudly to attract other magpies. The gathering of raucously calling magpies (up to 40 birds have been observed) may last for 10 to 15 minutes before the birds disperse and fly off silently.
Black-billed Magpie populations appear to be stable across their range, though regional declines have been noted in North Dakota and Nebraska. They have been vulnerable to toxic chemicals, particularly topical pesticides applied to the backs of cattle which magpies ingest when gleaning ticks off livestock. In the past Black-billed Magpies were persecuted by farmers, ranchers, and game managers who considered them to be vermin, but today they are fully protected under the Migratory Bird Treaty Act.
- Trost, C.H. 1999. Black-billed Magpie (Pica pica). In The Birds of North America, No. 389 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne’s Essential Field Guide Companion. Houghton Mifflin, New York.
- Sibley, D.A. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.
- Stanley, T.R. 2002. How many kilojoules does a Black-billed Magpie nest cost? Journal of Field Ornithology 73:292–297.
- USGS Patuxent Wildlife Research Center. 2011. Longevity records of North American birds.
Resident, with some regional winter movements.
In their range, Black-billed Magpies occasionally visit platform bird feeders and suet feeders. They are fairly common in small towns and may visit large yards.
Find This Bird
Black-billed Magpies are noisy, and they have a habit of sitting very conspicuously at the tops of trees or fenceposts, so they can be easy to hear and see. In flight their trailing tail feathers and bright, flashy white wing patches make them unmistakable. Keep an eye in the air for their graceful, gliding flights across open, brushy areas.