Harvest management of Tundra Swans Cygnus columbianus in North America

Abstract

Sport hunting of Tundra Swans in the U.S. is regulated under provisions of the Migratory Bird Treaty Act of 1918. Management plans cooperatively developed and agreed to between Flyway Councils and Federal wildlife agencies in Canada and the U.S. prescribe allowable harvest levels and provisions for regulating it. Harvests are managed by Eastern and Western Populations. Presently, hunts are authorized in specific locations during fall migration in the States of Alaska, Montana, Nevada, North and South Dakota, and Utah and on wintering areas in the States of New Jersey, North Carolina, and Virginia. A specified number of permits are approved by the USFW to participating states allowing each applicant to take one Tundra Swan per season. During 1979-88, the number of permits to harvest Western Population swans has averaged 3,552 per year. Of these, 1,075 swans are retrieved and 215 unretrieved. During 1986-88, an average of6,467permits have been issued to harvest Eastern Population swans. Of these, an average of 2,617 swans are retrieved and 302 unretrieved. In recent years, about 10,000permits are issued and account for a total kill of about 4,200 annually, including retrieved and unretrieved. Of this amount, 70% are derivedfrom the Eastern Population and 30% results from the Western Population. These harvest estimates account for less than 3% of the pre-season winter population estimate and are below the 10% harvest rate guideline specified in the management plans. Both Eastern and Western Populations of Tundra Swans have increased in numbers and expanded their distributions over the years since special hunting seasons were first established. Presently, these numbers exceed the populations goals prescribed by various management plans. To better assess the effects of hunting on Tundra Swans, special studies are needed to validate population estimates, identify subpopulations, determine seasonal movements and measure changes in recovery and survival rates.