Damage and Damage Identification

North American magpies; (a) Black-billed magpie, Pica pica; (b)Yellow-billed magpie, P. nuttalli

Magpies have come into conflict with humans in North America for quite some time. Poisons were used extensively in the 1920s and 30s to resolve serious depredations and livestock predation. During this time, magpie populations were greatly suppressed. Today, however, no toxicants are currently registered and populations have increased. Magpies cause a variety of problems, especially where their numbers are high. Most problems occur in localized areas where loose colonies have concentrated in close proximity to humans.

Magpies can cause substantial damage locally to crops such as almonds, cherries, corn, walnuts, melons, grapes, peaches, wheat, figs, and milo. Their damage is probably greatest in areas where insects and wild mast are relatively unavailable. Typically, other birds such as blackbirds and robins cause more damage to growers in fruit orchards and grain fields because of their greater abundance.

Magpies are often found near livestock where they feed on dung-and carrion-associated insects. They also forage for ticks and other insects on the backs of domestic animals. Perhaps the most notorious magpie behavior is the picking of open wounds and scabs on the backs of livestock. If they find an open wound, such as that from a new brand, they may pick at it until they create a much larger wound. The wound may eventually become infected and, in some instances, may kill the animal. Magpies, like ravens, may peck the eyes out of newborn or sick livestock.

Magpies rob wild bird and poultry nests of eggs and hatchlings. Typically, that does not affect wild bird populations except in local areas where limited habitat makes nests easy to find. They can be very destructive to poultry, however, especially during the nesting season when magpie parents are gathering food for their young.

Magpie roosts can be a nuisance because of excessive noise and the odor associated with droppings. During winter, magpies may congregate in loose colonies and form nightly roosts of hundreds after they have migrated southward and to lower elevations. They typically roost in dense thickets or trees.

Legal Status

Magpies are protected as migratory non game birds under the Federal Migratory Bird Treaty Act. Under the Federal Codes of Regulation (CFR 50, 21.43) it is stated, however, that “a Federal permit shall not be required to control . . . magpies, when found committing or about to commit depredations upon ornamental or shade trees, agricultural crops, livestock, or wildlife, or when concentrated in such numbers as to constitute a health hazard or other nuisance. . . .” Most state or local regulations are similar, but consult authorities before taking any magpies.