Support Across Constituencies - Mute Swans

American Bird Conservancy * Archbold Biological Station * Atlanta Audubon Society * Audubon Naturalist Society of the Central-Atlantic States * Audubon Pennsylvania * Chappee Rapids Audubon Society * Cooper Ornithological Society * Cornell Laboratory of Ornithology * Delmarva Ornithological Society * Ducks Unlimited * Environmental Defense * Georgia Ornithological Society * Green-Rock Audubon Society * Illinois Audubon Society * International Assn. of Fish and Wildlife Agencies * Izaack Walton League of America * Madison Audubon Society * Maryland Ornithological Society * National Audubon Society * New Jersey Audubon Society * Riveredge Bird Club * Tennessee Ornithological Society * The Waterbird Society * Wildlife Management Institute * Wisconsin Audubon Council

July 16, 2003
Division of Migratory Bird Management
4401 N. Fairfax Dr., MBSP 4107
Arlington, VA 22203

Dear U.S. Fish and Wildlife Service:
The undersigned groups, all concerned with the conservation of native, indigenous birds in the U.S., submit the following comments in support of Alternative 2, the proposed action, in the U.S. Fish and Wildlife Services (FWS) draft environmental assessment of the management of Mute Swans (Cygnus olor) in the Atlantic Flyway, published in the Federal Register on July 2, 2003. The Integrated Population Management under the proposed action would allow use of non-lethal as well as lethal methods to reduce the burgeoning Mute Swan population in the east by 67%. Mute Swan numbers would be reduced from 14,300 animals to 4,675 in five to ten years to comport with the recommended population goal of the Atlantic Flyway Mute Swan Management Plan, a reduction to pre-1985 levels. Under the proposed action, state and federal agencies would apply for MBTA depredation permits from the FWS and would operate with an integrated population management program under these permits.

The Draft EA clearly documents the exponential growth the Mute Swan has undergone in the East and throughout the U.S. Over two-thirds of the U.S. Mute Swan population is in the East.

We fully support Alternative 2 and the significant reduction of Mute Swans from the wild. But we would suggest that the FWS consider a nationwide Depredation Order in the future for this exotic species with a goal of the elimination of wild Mute Swan populations. There is no biological basis for supporting continued populations of Mute Swans in the wild while there are sound ecological reasons to eliminate all wild populations. FWS should work to attain that goal in the long-term, and not support the maintenance of a wild population of an invasive species. We believe such reductions/elimination are necessary because:

Next to habitat loss and alteration, invasive species have been identified as the greatest threat to birds in the U.S. Up to 46% of the plants and animals Federally listed as endangered species have been negatively impacted by invasive species. The Mute Swan is a large invasive species that has demonstrably negative impacts on other species, including native birds.

The large, aggressive Mute Swan has attacked and killed other birds and has extirpated breeding colonies of waterbirds. In Maryland, as noted in the Maryland Mute Swan Task Force Report, "One of the more serious conflicts between mute swans and native Maryland wildlife occurred in the early 1990's, when a molting flock of about 600_1,000 nonbreeding mute swans excluded black skimmers (Rynchops niger), a state threatened species; least terns (Sterna antillarum), classified as a species in need of conservation; and common terns (Sterna hirundo) from using the oyster shell bars and beaches in the Tar Bay area of Dorchester County for nesting sites." Tar Bay was the only remaining natural nesting site for Least Terns and Black Skimmers in the Chesapeake Bay.

Mute Swans impact other swans and waterfowl. According to the Maryland Task Force Report, "Mute swans are believed to pose a significant threat to the well-being of the Chesapeake Bay tundra swan population (W.J.L. Sladen, Swan Research Program at Airlie, VA, pers. commun.)". In a Rhode Island study, one pair of mute swans vigorously defended a five acre pond, preventing use by other waterfowl (NY DEC 1993). In central New York, three pairs of captive mute swans killed at least 50 ducks and geese (mostly young birds) on a small zoo pond over a 20_month period (NY DEC 1993). Such behavior may be a factor in inhibiting the recovery of such native species as Black Ducks. In addition, Mute Swans consume SAV preferred by many native waterfowl species.

Mute Swans consume huge amounts of Submerged Aquatic Vegetation (SAV). George Fenwick's doctoral dissertation (1983) on Mute Swans in the Chesapeake Bay showed that the male Mute Swan consumed 34.6% of their body weight per day and females consumed 43.4%. Based on Dr. Fenwick's study, the Maryland Task Force Report notes that "Assuming that an adult/subadult mute swan consumes an average of 3.789 kg wet weight of SAV per day (Willey and Halla 1972), a population of 4,000 swans has the potential to consume more than 12 million pounds of SAV annually (L. Hindman, MD DNR). Consumption of immature seeds, removal of biomass before plant maturation, and uprooting of whole plants may have a very negative effect on SAV with minimal consumption (M. Naylor, MD DNR, pers. commun)." Scientists at the Patuxent Wildlife Research Center have recently concluded that the introduced swan's diet is composed nearly entirely of vegetation during all seasons of the year. Mute Swans relied heavily on SAV with Widgeon Grass (Ruppia maritima) constituting 56 % and Eel Grass (Zostera marina) 43 % of their food. See (Perry et al 2000). These scientists noted localized depletions (eat-outs) of SAV during the growing period. The FWS Draft EA notes that the current population of Chesapeake Bay Mute Swans consumes almost 10 percent of the total biomass of submerged aquatic vegetation in the Bay. These grasses are critical to many other avian species, to recovery of fisheries (Blue Crabs), and to the general water quality of the Bay and other water bodies.

Mute Swans are attractive birds and hence their control/elimination is made more difficult. Lethal control upsets certain segments of the population but to reduce or stabilize populations of Mute Swans, adults must be removed. Dr. Scott A. Petrie is Research Director of the Long Point Waterfowl and Wetlands Research Fund. He has authored a research paper on Mute Swans and he has published other work showing that Mute Swans have grown by 10% to 21% a year on the shores of Lake Erie and Lake Ontario, despite egg addling and oiling. In his paper published February 2002 in Birding, he finds THAT ADDLING EGGS DOES NOT WORK to reduce or stabilize populations of Mute Swans and that adults must be removed. Rhode Island began a control program of egg addling and pricking in 1979; despite the fact that 9,378 eggs have been destroyed in 1,629 nests over a period of 22 years, the population increased by over 500% (Allin, personal communication). Population models indicate that the most effective way to reduce population growth for a long-lived species such as the Mute Swan is to reduce adult survival rates (e.g., Schmutz et al. 1996) Schmutz, J.A., R.F. Rockwell, M.R. Peterson. 1997. Relative effects of survival and reproduction on the population dynamics of emperor geese. J. Wildl. Mange. 61(1):191-201.

Based on the best science obtainable, the take of adult Mute Swans is essential to prevent a substantial escalation in the Mute Swan population and the damage they cause to native avian species, SAV, and water quality. Without aggressive efforts to control and eliminate Mute Swans, the Mute Swan population will continue to rapidly increase. The Mute Swan population in the Chesapeake Bay has grown from 5 escaped birds in 1962 to about 4,500, including birds in Virginia and Maryland. An EIS is not necessary for this exotic species, depredation permits should be continued to be issued, and a General Depredation Order considered for the future.

Respectfully submitted on behalf of:

George Fenwick, Ph. D., President
American Bird Conservancy
P.O. Box 249
The Plains, VA 20198

Bonnie Bowen, Ph. D., President
Cooper Ornithological Society
124 Science II
Ames, IA 50011

John W. Fitzpatrick, Ph. D., Director
Cornell Laboratory of Ornithology
149 Sapsucker Woods Road
Ithaca, NY 14850

Perry Plumart, Director
Government Relations
National Audubon Society
1150 Connecticut Avenue, N.W.
Washington, D.C. 20036

John Baughman, Executive Vice-President
International Assn. of Fish and Wildlife
444 N. Capitol Street, N.W.
Suite 544
Washington, D.C. 20001

E. A. Schreiber, Ph. D.
The Waterbird Society
National Museum of Natural History
E 607 MRC 116
Smithsonian Institution
Washington, D.C. 20560

Daniel R. Southworth, MS
Maryland Ornithological Society
9763 Early Spring Way
Columbia, MD 21046

Susan L. Peterson, Ph. D.
Conservation Chair
Delmarva Ornithological Society
P.O. Box 4247
Greenville, DE 19807 James A. Mosher, Conservation Director

Izaack Walton League of America
707 Conservation Lane
Gaithersburg, MD 20878

Terry Z. Riley
Director of Conservation
Wildlife Management Institute
1146 Nineteenth Street, N.W., Suite 700
Washington, D.C. 20036

Timothy Male, Ph. D.
Senior Wildlife Scientist
Environmental Defense
1875 Connecticut Avenue, N.W.
Washington D. C. 20009

Reed Bowman, Ph. D., Director
Avian Ecology Lab
Archbold Biological Station
P.O. Box 2057
Lake Placid, FL 33862

Eric Stiles, Vice President for Conservation and Stewardship
New Jersey Audubon Society
P.O. Box 693
11 Hardscrabble Road
Bernardsville, NJ 07924

Paul T. Zeph, Executive Director
Audubon Pennsylvania
100 Wildwood Way
Harrisburg, PA 17110

Robert Hoffman, Ph. D.
Director of Operations
Great Lakes/Atlantic Regional Office
Ducks Unlimited, Inc.
331 Metty Drive, Suite 4
Ann Arbor, MI 48103

Neal Fitzpatrick, Executive Director
Audubon Naturalist Society of the Central-Atlantic States
8490 Jones Mill Road
Chevy Chase, MD 20815

Melinda Welton, Conservation Chair
Tennessee Ornithological Society
5241 Old Harding Road
Franklin, TN 37064

Marilyn F. Campbell, Executive Director
Illinois Audubon Society
P.O. Box 2418
Danville, IL 61834

Karen Etter Hale, Executive Secretary
Madison Audubon Society
222 S. Hamilton Street, Suite 1
Madison, WI 53703-3201

Noel J. Cutright, Ph. D., President
Riveredge Bird Club
3352 Knollwood
West Bend, WI 53095

Marsha Cannon, President
Wisconsin Audubon Council
222 S. Hamilton Street, Suite 1
Madison, WI 53703-3201

Wendel J. Johnson, Ph. D.
Conservation Chair
Chappee Rapids Audubon Society
P.O. Box 1133
Marinette, WI 54143

Neil Deupree, President
Green-Rock Audubon Society
419 S. Franklin Street
Janesville, WI 53545

Carol Lambert, Director
Atlanta Audubon Society
P.O. Box 29189
Atlanta, GA 30359

Gail Russell, President
Georgia Ornithological Society
1317 Highland Bluff Drive, SE
Atlanta, GA 30339-3251

Back to In Focus - Mute Swans
Posted August 6, 2003