EAGLE DAMAGE CONTROL
Bart W. O’Gara
Research Biologist (retired)
US Fish and Wildlife Service
Montana Cooperative Wildlife Research Unit
The University of Montana
Missoula, Montana 59812
Additional Eagle Control Information
Fig. 1. Left, Bald eagle, Haliaeetus leucocephalus;
right, golden eagle, Aquila chrysaetos
Both bald and golden eagles and their nests and nest sites are protected by the federal Bald Eagle Protection Act and state regulations. In June 1940, legislation was passed that outlawed killing, possessing, selling, or trading any live or dead bald eagle, or any part of a bald eagle, including feathers, eggs, and nests. In 1962, the same protection was afforded the golden eagle. Provisions in these laws allow specific permits to be issued by the US Department of Interior for the taking of eagles or their parts for scientific research, for exhibitions and Indian religious purposes, and for control of predation to domestic livestock (50 CFR, Part 22). Permits for control of eagles to prevent or reduce predation on livestock, however, have not been issued by the US Department of Interior since 1970. Also, regulations promulgated by the Secretary of Interior under authority of the Endangered Species Act of 1973 (as amended) prohibit “taking” of an endangered species, such as bald eagles. Because golden eagles also are protected, they too cannot be “taken.” Congress has defined the term take as follows: “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.”
A depredation permit from the US Department of Interior is required to carry out any eagle damage control activities. This requires a formal consultation and biological assessment under Section 7 of the Endangered Species Act for bald eagles. At present, permits to take, harass, or scare depredating golden eagles are issued routinely to the western Regional Director of the USDA-APHIS-Wildlife Services by the USFWS. Only USDA-APHIS-Wildlife Services personnel are permitted to engage in eagle damage control activity under such permits.
Damage Prevention and Control Methods
Eagles rarely attack livestock around buildings or pens. Therefore, livestock confined in buildings or pens of 1 to 2 acres (1/2 to 1 ha) usually are safe from eagles. Fences, however, are no constraint to eagles; livestock must be protected by other means.
Cultural Methods and Habitat Modification
A common practice for many sheep and goat producers is to avoid use of pastures where predation is severe until lambs and kids are several weeks old. This practice may reduce exposure of individual flocks or herds to predation, but it is not always effective. It may, however, cause predators to shift their attention to livestock owned by other operators.
Eagles prefer relatively open areas in which to take their prey. Lambs and kids are much less vulnerable to eagle predation in brushy and wooded areas. While use of such pastures may not completely prevent eagle predation, it may help to protect lambs and kids up to 4 to 6 weeks of age. Predation by eagles is seldom a problem after lambs and kids have reached 6 weeks of age.
Herding of livestock, where feasible, usually will reduce eagle predation because humans tend to frighten eagles. Herding may be only partially effective, however, because eagles, like other predators, adapt to existing conditions.
Shifting the lambing and kidding seasons to an earlier or later period may also help to reduce or prevent eagle predation, but the decision must be based on the availability of pasture, plant phenology, season and weather, availability of labor, marketing constraints, and other considerations. In some areas, such a shift may cause increased exposure of young livestock to other predator species.
Shed lambing and kidding is effective in preventing eagle predation during the confinement period. Its limitations include the availability of space, the quality and costs of feed necessary to ensure and maintain milk production for lambs and kids, and the length of confinement. Unless the young are confined up to a month or more, shed lambing and kidding will provide protection when the chance of eagle predation is lowest. Eagles generally take older lambs or kids that are running and playing some distance from flocks, not the younger ones, who usually stay close to their mother and within the flock. Predation is most severe on young that are at least 2 to 4 weeks of age. Confinement of sheep and goats also may be a very costly management decision for forage utilization where high quality forage is available in pastures and weather does not present a constraint to the use of that forage.
Carrion removal may help limit the size of local eagle populations. Eliminating the eagles’ food source may force a potential problem to move elsewhere. It may, however, encourage the eagles to kill lambs or kids. If eagles depend heavily on carrion in an area where young livestock are to be protected, the eagles must either have an alternate food source or be persuaded to move.
Little information is available on the effects of guard dogs to prevent eagle predation. Some dogs, including breeds other than guard dogs, will chase birds. They would probably be more effective in protecting sheep or goats in small pastures than in large pastures and open range conditions, particularly where livestock are spread over large areas.
Sonic devices have been tested and show little benefit in preventing or reducing eagle predation.
Scarecrows, made from 2 x 4-inch (5 x 10-cm) lumber and chicken wire (Fig. 4) and dressed in pants or skirts, shirts, and hats, may keep eagles away from an area for up to 3 weeks. The chicken wire bodies allow the arms to wave in the wind. Clothes can be purchased secondhand from Goodwill Industries for about $3.50 per scarecrow. The frame is made of standard grade lumber at a cost of about $6.50 per scarecrow; a lesser grade or scrap lumber should reduce the cost. Almost anything can be used as a stand, including 2 x 4s or existing fence posts. The chicken wire is attached to the 2 x 4s with a staple gun, which also comes in handy for making field repairs. Building time is about 1/2 hour. Fluorescent orange paint can be sprayed on the backs and chests of scarecrows and their arms hung with shiny pans to increase visibility. Erect scarecrows on a high ridge or point, where sheep and goats usually bed. Most eagle predation occurs about sunup so the lambs or kids will be close to the scarecrows during the time of greatest danger. When eagles start to habituate to scarecrows, harass them by shooting cracker shells near perched or low-flying eagles. This activity will reinforce the fear associated with humans and scarecrows. A permit is required for such harassment. In areas where ravens are common and preying on lambs or kids, shooting or shooting at ravens keeps eagles wary of scarecrows; again, a permit is required for this activity.
No repellents are registered or effective in reducing eagle predation.
No toxicants are registered or permitted for use in preventing or controlling eagle predation.
Trapping, Snaring, and Shooting
Trapping, snaring, or shooting eagles is illegal, except by permit. Regulations permit the Director, USFWS, to issue permits for removal of depredating eagles “under permit by firearms, traps, or other suitable means except by poison or from aircraft.” However, by policy of the Secretary, US Department of Interior, such permits are not issued. The sole exception is very limited live-trapping or net-gunning from a helicopter and transplanting of eagles by USFWS and USDA-APHIS-Wildlife Services personnel. Livestock owners who have, or suspect that they have, eagle depredation should contact the USFWS or USDA-APHIS-Wildlife Services for assistance and evaluation. Live trapping and removal of depredating eagles by the USFWS is permitted under certain conditions, and a limited amount of such control is carried out. Net gunning from a helicopter allows quick and selective removal of depredating eagles from an area.
Scott E. Hygnstrom;
Robert M. Timm;
Gary E. Larson
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