MAGPIES DAMAGE IDENTIFICATION

Thomas C. Hall Fig. 1. North American magpie (Pica pica)
Wildlife Biologist
USDA-APHIS-Wildlife Services
7104 Bellrose Aveneu, NE
Olympia, WA 98502

For additional information click Magpies

Fig. 1. North American magpies; (a)Black-billed magpie Pica pica; (b) Yellow-billed magpie, P.nuttalli

Damage Identification

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.

Economics of Damage and Control

Magpies benefit agricultural producers by consuming thousands of insects and by scavenging, but they can also have a negative local impact that can turn severe. Losses are greatest where nesting magpies are in close proximity to poultry producers or concentrated in numbers that constitute a problem. Damage may increase dramatically when wild mast and insects are relatively unavailable.

Each producer in the range of magpies should develop a management plan before magpies become a problem. Preparedness enhances the success in decreasing depredation. The cost of the different options for control should be weighed and compared with the success in controlling the problem. Long-term solutions should be implemented wherever possible, but be prepared to take remedial control measures when necessary. Prior to the depredation season, an estimate of the magpie population and the availability of alternate food sources should be determined to make preparations accordingly.

Editors

Scott E. Hygnstrom; Robert M. Timm; Gary E. Larson

Prevention and Control of Wildlife Damage Logo 1994

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994

Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska -Lincoln

United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control

Great Plains Agricultural Council Wildlife Committee

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