Mute Swans in Maryland: A Statewide Management Plan
Maryland Department of Natural Resources
Wildlife and Heritage Service
April 14, 2003

MANAGEMENT OBJECTIVES AND STRATEGIES

Mute swan population management objectives and strategies for the next five years are listed on the next several pages. In 2008, the management plan will be assessed and revised based on progress towards the plan’s goals and objectives and the results of research and monitoring efforts.

Public Outreach and Education

Implementation of mute swan management in Maryland must occur concurrently with an effort to educate and inform Maryland citizen’s about mute swans. These programs should convey an understanding of the status of the mute swan population in Maryland, the impact of mute swans in the Bay’s ecosystem, and the problems they create for people.

Objective: Increase public awareness about mute swans and their impact to the Bay’s Living Resources

Strategy A-1: Conduct a statewide, random survey of public knowledge, perceptions and values regarding mute swans in Maryland.

Strategy A-2: Develop and implement a comprehensive mute swan communication program. Target programs to specific demographic groups, as well as shoreline owners and watershed community residents. There is a critical need to increase public awareness of the difference between mute swans and native tundra swans and the impacts that mute swans have on the Chesapeake Bay ecosystem. Emphasis should also be placed on discouraging the winter-feeding of mute swans for it increases their winter survival.

Population Management and Resource Protection

An aggressive egg-addling program began in 2001 and will be continued, with the objective of reducing reproductive output (e.g., cygnet production) by at least 60%. In addition to efforts by state and federal wildlife managers, the DNR will continue to involve nongovernmental organizations such as those concerned with tributary conservation.

Population modeling and experience in other states demonstrates that egg addling, while a valuable tool, is unlikely to reduce the size of the swan population. In Rhode Island, a long-term egg-addling program reduced recruitment by 80%, but the number of nesting pairs continued to grow. Further, egg addling does not address the impacts on SAV and other living resources caused by an overabundance of mute swans.

To achieve the management goals and objectives within this plan, it will be necessary to remove subadult and adult swans. The removal of subadult and adult mute swan from the wild will be linked to the protection of key resource areas.

These areas, termed “Swan-Free Areas” include:

(1) wetlands, including SAV areas, identified to achieve the goals and objectives of the Chesapeake 2000 Agreement; (2) wetlands on Federal National Wildlife Refuges and other Federal lands, State Wildlife Management Areas, Natural Resources Management Areas, State Parks, and other state-owned and managed lands; (3) SAV and emergent wetland restoration areas; (4) colonial waterbird nesting areas; and (5) black duck nesting habitats (Appendix D). Lethal methods to remove swans will occur where non-lethal methods to exclude swans from Swan-Free Areas are not effective or practical. Lethal methods will include shooting or capture and euthanasia. Small numbers of swans may be captured and placed in permitted waterfowl collections. However, mute swans will not be relocated to other wetland habitats in Maryland. Federal guidance for permit issuance involving mute swans prohibits the release of mute swans into areas outside their existing range.

Management actions identified in Strategies B-1 and B-2 that will be used to reduce the swan population within areas of the state are authorized under NR Article, Section 10 - 206 (Appendix B). DNR personnel are experienced and professional in their use of wildlife control methods, and methods are applied as humanely as possible. For situations where it is necessary and practical to capture and euthanize swans, the DNR follows euthanasia methods recommended by the American Veterinary Medical Association.

Objective: Exclude or remove all mute swans from Swan-Free Areas to afford protection to habitats critical to the Bay’s Living Resources; reduce the mute swan population as quickly and efficiently as possible, consistent with activities to protect, restore and enhance the Bay’s Living Resources.

Strategy B-1: The DNR will continue to implement an aggressive egg addling effort to reduce hatching success by at least 60%. Implementation of this strategy will slow the population growth rate and reduce the number of adult swans that would have to be removed to achieve the management goal. The DNR will make every effort to treat all swan nests located in public waters and on private property with landowner permission. The DNR will continue to involve local tributary organizations and other nongovernmental organizations to oil swan eggs.

Strategy B-2: Starting in 2003, the DNR will seek federal authorization (Depredation Order 50 CFR Part 21.41) to begin removing mute swans from Swan-Free Areas. Beginning in 2003, the DNR will initiate activities to either prevent or remove mute swans from occupying Swan-Free Areas. No federal permit is required to scare mute swans. Recognizing that swans impacting SAV beds and other habitats classified as Swan Free Areas may occur immediately adjacent to these habitats, the scope of swan control efforts may be expanded to include these adjacent areas. If non-lethal methods to prevent mute swans from occupying Swan-Free Areas are ineffective or impractical, swans will be removed using lethal methods. Swans killed under this strategy may be donated to public museums or public scientific and educational institutions for scientific or educational purposes, or charities for human consumption.

Federal guidance for permit issuance involving mute swans prohibits the release of mute swans into areas outside their existing range. With federal authorization, small numbers of swans may be captured, sterilized, and placed in existing captive waterfowl flocks. However, the DNR will not authorize the relocation of swans, including same-sex pairs, to natural habitats in Maryland. The relocation of mute swans into unoccupied habitats would increase the distribution of mute swan in Maryland.

The relocation of same-sex pairs does not prevent breeding if a bird of the opposite sex locates and enters the relocation site. The possibility of breeding with wild, opposite-sex birds is high and would contribute to expansion of the breeding population, which is contrary to the objective of this management plan and USFWS and Atlantic Flyway Council policies.

With federal authorization, mute swans may be captured and relocated to zoos where the birds would be used for scientific and educational purposes. However, the DNR will prescribe restrictive permit conditions for the possession of swans through the existing federal permit process (50 CFR 21.25). Any relocation of swans to other jurisdictions shall be done only with the approval of the USFWS and the government agency responsible for wildlife conservation in that jurisdiction and in accordance with any flyway, national, or international mute swan management plan, policy, law, or regulation.

Strategy B-3: The DNR will work with other states, flyway councils, the International Association of Fish and Wildlife Agencies, and the USFWS to develop federal regulatory language to facilitate efficient population management. Reducing the size of the mute swan population in the short-term will require active intervention by the DNR. However, if the population can be reduced to a level that alleviates resource concerns, removing regulatory barriers will help maintain the population at an acceptable level.

Strategy B-4: The DNR will work with the Maryland General Assembly to amend existing state law (NR Article, Section 10-101), which classifies the mute swan as a Wetland Game Bird. The statute should be amended to include only native migratory game bird species. The DNR will also encourage the Maryland General Assembly, consistent with federal regulations, to amend NR Article, Section 10-101, by adding the mute swan, Australian black swans, and other invasive, non-native bird species to the list of unprotected birds in Maryland. Presently, the only non-native, unprotected birds listed in this law are the English house sparrow and European starling.

Captive Mute Swan Management

Captive swans that either escape or are released may be insignificant in terms of numbers, but they can dramatically affect distribution by introducing swans to new areas of the state. The possession of captive mute swans is now regulated by federal permit (50 CFR 21.25). Federal permits authorizing activities involving live mute swans will include restrictive conditions to ensure that permitted activities do not facilitate expansion of the range or population of mute swans, for example, prohibiting the release of live mute swans or their eggs into areas outside their existing range, or onto any federal lands. State regulations and policies will be developed to further prevent the release and escape of mute swans into the wild. Natural Resources Article, Sections 10-205, 10-903, and 10-905 (Appendix B) give the authority to the DNR to adopt regulations to restrict, possession, purchase, sale and exportation and importation of wildlife. Further, the DNR has the authority to require persons who possess mute swans to obtain a state permit.

Objective: Prevent the escape and reproduction of captive mute swans.

Strategy C-1: In 2003, promulgate regulations and/or add conditions to federal and state permits that prohibit the sale, trade, barter, and importation of mute swans, or their eggs, in Maryland.

Strategy C-2: Persons possessing mute swans now must possess either a Federal Waterfowl Sale and Disposal Permit or a federal Form 3-186. Persons possessing mute swans will be required by the DNR to secure a state permit. However, the DNR shall only permit the possession of mute swans at locations where swans have legally been held in captivity prior to enactment of state regulations. After this date, the DNR will not authorize any additional state permits to purchase or import mute swans.

Strategy C-3: In 2003, promulgate state regulations or add conditions to all federal and state permits governing the possession of migratory birds, prohibiting the release of mute swans to the wild. Following capture of healthy swans and/or recovery of sick or injured swans, every effort will be made by the DNR to place the swans in captivity at a facility permitted to possess mute swans. In the event that this is not possible, swan(s) will be humanely euthanized by a veterinarian authorized by DNR in accordance with a federal permit.

Relief of Human Safety and Nuisance Conflicts

Natural Resources Article, Sections 10-205 and 10-206 (Appendix B) and federal regulations (50 CFR 21.41) (Appendix C) authorize the DNR to resolve conflicts between mute swans and people by allowing either the capture or lethal removal of mute swans.

Objective: Reduce conflicts between mute swans and people.

Strategy D-1: The DNR with the U.S. Department of Agriculture’s Wildlife Services will continue to provide technical information and guidance to property owners who are experiencing nuisance, safety, and habitat depredation problems caused by mute swans. Wildlife Services and DNR personnel may suggest the use of non-lethal, lethal, or a combination of techniques to resolve swan conflicts. The recipient of technical assistance is responsible for securing the required federal and state permits before implementation of recommended, lethal control actions.

Strategy D-2: In 2003, the DNR shall seek a Federal Depredation Order that will authorize property owners, land or water management authorities, municipalities, and other responsible parties in Maryland to control or remove mute swans occurring on lands or waters under their jurisdiction. Such a depredation order will apply to situations where control or management of mute swans is necessary to protect personal property, human health and safety, or native plant and animal resources. The depredation order will include guidelines to ensure, to the extent possible, that control measures used are safe and effective. No federal or state permit is needed to scare swans. Property owners will have primary responsibility for deciding, on a case-by-case basis, whether mute swans on their property are desirable and what control measures are acceptable. The DNR will recommend that effective and practical non-lethal methods be used to resolve the problem where appropriate, before lethal control is initiated by the permittee. Prior to the adoption of a Federal Depredation Order in 50 CFR Part 20, property owners will be required to obtain a Federal Depredation Permit to control or remove mute swans occurring on lands or waters under their jurisdiction. Federal permits will be reviewed by the DNR and shall include conditions to ensure, to the extent possible, that control measures used are safe, effective, and practical. However, the permittee is responsible for implementation of any and all control actions.

Population Monitoring and Research

Objective: Monitor the size and distribution of the mute swan population and the effectiveness of management actions.

Strategy E-1: Conduct an annual spring aerial survey of mute swans in the tidal portions of the Bay to determine the locations of active mute swan nests and breeding pairs to facilitate effective egg addling and removal of swans from Swan-Free Areas.

Strategy E-2: Conduct an annual summer aerial survey of mute swans on the tidal portions of the Bay to determine the size and distribution of the swan population. This survey will also be used to measure the effectiveness of population control efforts and provide the locations of breeding pairs for removal of swans from Swan-Free Areas, and other population control efforts.

Objective: Conduct additional research that will increase understanding of the role of mute swans in the Chesapeake Bay ecosystem and their impacts on living resources. This research should contribute to achieving mute swan management goals and objectives.

Strategy F-1: Beginning in 2003, investigate further the role of mute swan herbivory on SAV growth, biomass, plant survival, and regeneration and reproduction, especially as it relates to the availability of SAV to wintering waterfowl and the achievement of SAV restoration goals.

Strategy F-2: Beginning in 2003, determine the role of interspecific competition between mute swans and native wildlife, especially the impact of mute swans on wintering tundra swans.

Objective: Investigate the use of non-lethal swan population control methods. 

Strategy G-1: The DNR will continue to evaluate non-lethal methods of controlling mute swans. Such methods shall include exclusion, hazing (e.g., harassment), and any other methods that may become available.

Strategy G-2: The DNR will evaluate the effectiveness of sterilization of male swans as a method of reducing annual cygnet production at the local level. The use of this technique as a future management tool is conditional upon the success of this research. This technique will not be used as a general population control method. Rather, sterilization may be used at specific sites where the removal of breeding pairs may not be practical. The DNR will seek federal authorization (50 CFR 21.27) to conduct this investigation.