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.Back to top
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.Back to top
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.
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.
|Clutch Size:||1-9 eggs|
|Number of Broods:||1 brood|
|Egg Length:||1.2-1.5 in (3-3.7 cm)|
|Egg Width:||0.8-1.0 in (2-2.5 cm)|
|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.|
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. Back to top
Black-billed Magpies populations have been decreasing approximately 9% per year for a cumulative decline of about 38% between 1966 to 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 6 million and rates them 9 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. However, Black-billed Magpies are vulnerable to toxic chemicals, particularly topical pesticides applied to the backs of cattle which magpies ingest when picking 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.Back to top
Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
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Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
Trost, Charles H. (1999). Black-billed Magpie (Pica hudsonia), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.