Frequently Asked Questions About Mute Swans
Why are they called mute swans?
Overall, they don't make very much noise, especially when comparing them to other native swans such as trumpeter swans. If they become aggravated, they are likely to hiss and beat their wings.
What is an invasive species?
Invasive species are non-native species that become established, spread widely and cause harm to an ecosystem. Invasive species compete with native species for food and habitat, and can directly or indirectly kill or displace native species, degrade habitat and alter food webs. Invasive species can also have significant economic effects on waterfront property values, tourism, utilities and other industries.
Are mute swans invasive, non-native, or both?
Both. Mute swans are not native to Michigan, or to North America. They were brought to this country from Europe. Mute swans were introduced to this continent in the mid-1800s to adorn city parks and large estates. It is widely thought that all North American mute swan populations originated from the release or escape of individuals from these early captive flocks.
Mute swans are invasive because they are non-native species that have become established and spread rapidly, causing negative impacts such as competition with native wildlife, displacement of native species and degradation of wetland habitat.
Where are mute swans from?
Mute swans were brought to the United States from Europe in the late 1800s. Mute swans that escaped from captivity have established populations in a number of states. The mute swan population in Michigan originated from one pair introduced in Charlevoix County in 1919.
Are mute swans in Michigan year-round?
Yes. Most mute swans in Michigan do not migrate very far. They will stay in an area over winter as long as there is open water and a food source.
How many mute swans are there in Michigan and how fast is the population growing?
In 2010, the DNR estimated that there were approximately 15,500 mute swans in Michigan. That number had increased from about 5,700 in 2000. The DNR estimates that the mute swan population increases about 9-10 percent each year.
Mute swan populations have the potential to increase rapidly if unchecked. Mute swans are relatively long-lived, contributing to their population growth. One study estimated the annual survival rate of young mute swans in Michigan ranged from 84-88 percent a year. From ages 4-8 years, annual survival increased to 93-98 percent per year. At age five, annual survival averaged 98 percent. Although essentially non-migratory, survival rates remain high through winter because the swans move to warm water discharges and rivers. Mute swans can live up to 19 years in the wild, and breeding adults raise about five cygnets each year.
Michigan now has one of the highest, if not the highest, populations of mute swans in North America.
How does the DNR know how many mute swans there are?
The mute swan population in Michigan is tracked twice yearly by the DNR. First, during a mid-winter waterfowl count conducted in early January, then by the Michigan Spring Breeding Waterfowl Survey conducted each April-May. Mute swan population estimates are derived each year using data from the Spring Breeding Waterfowl Survey. This is an established aerial survey that the DNR has participated in since 1991. Flights are conducted at low elevation, slow speeds and follow the same transect routes each year. The survey methodology used is scientifically sound and proven and used by other states and Canadian provinces.
Why are mute swans a problem?
Mute swans are a problem for three primary reasons: they pose a threat to humans, endanger native wildlife and destroy wetland habitat. As the mute swan population continues to grow in Michigan, the damage and conflicts they create have long-term effects.
Do mute swans attack humans?
Yes. Mute swans are large, conspicuous birds and have little fear of humans. They are easily observed by the public and offer a chance for people to come in close contact with wildlife. Each year, the DNR gets reports of mute swan attacks on people in watercraft and on shore. These situations all pose potentially dangerous results, and as the mute swan population grows, so do the conflicts.
Mute swans begin nesting in the early spring. Nesting mute swans can be very aggressive to humans who come too close to their territory. Mute swans will attack humans, especially small children, who get too close to their nest or young. Canoeists, kayakers and those operating personal watercraft have also been attacked when too close to mute swan territories. Mute swans are aggressive and may pose a danger to humans and can in certain situations effect human use of property when humans are excluded from nesting areas by swans defending their territories.
How do mute swans endanger native wildlife species?
Mute swans are one of the world's most aggressive waterfowl species, especially during nesting and brood-rearing. Mute swans exhibit aggression toward other waterfowl and can displace native waterfowl from their nesting and feeding areas by attacking, injuring and even killing other birds.
In Michigan, of particular concern are native breeding waterfowl and water birds such as trumpeter swans (state threatened), Canada geese, ducks, common loons (state threatened) and black terns (state special concern).
Mute swans feed primarily on water plants. By feeding heavily on this food source, mute swans reduce the availability of these plants to native wildlife, and may ultimately reduce the carrying capacity of wetlands for native wildlife species including birds, mammals, amphibians and fish.
Wildlife biologists have concern over the declining numbers of native duck species such as canvasbacks and scaup. These diving ducks feed on particular aquatic plants and are negatively impacted when mute swans reduce or eliminate this food source.
Why is the native trumpeter swan important?
The trumpeter swan is native to Michigan, and is on our state's threatened species list. It has been on the road to recovery; however, the increasing presence of the invasive mute swan is threatening the breeding success of this native bird. To ensure the protection of the trumpeter swan, the mute swan population must be drastically reduced.
The DNR's efforts to protect the trumpeter swan in Michigan are a commitment to the North American Trumpeter Swan Restoration Plan. Michigan's plans do not include a goal to increase trumpeter swan populations to a level that would sustain hunting.
How can I tell the difference between mute and trumpeter swans?
The most notable difference between mute swans and the two native swan species found in Michigan (trumpeter swan and tundra swan) is that adult mute swans have orange bills. The two native swans have black bills. Mute swans also have a black knob on the top of their bill, that is absent in the native swan species. Mute swans typically have an "S"-shaped curve to their neck, while trumpeter swans have a "C"-shaped curve. Mute swans are also generally quieter than trumpeter swans, which have a loud trumpet-like call.
How do mute swans destroy wetland habitat?
Mute swans feed primarily on water plants. Adult mute swans consume large quantities of these plants (about four to eight pounds per swan per day) and often uproot more plants than they actually consume. As mute swans occupy habitat year-round in many locations, there is potential for depletion of this aquatic vegetation by continuous feeding.
The wetland plants that mute swans remove play an important role in aquatic ecosystems by providing both food and cover to a variety of vertebrate and invertebrate species. Many wildlife and fish species feed on animals that live in these plants and use the vegetation for nesting or shelter. When mute swans remove these plants, they can negatively alter the entire wetland ecosystem.
What do mute swans eat?
Mute swans feed primarily on aquatic plants such as pondweed, coontail, waterweed, wild rice and wild celery.
What is the DNR's goal for mute swans?
The DNR's short-term goal is to reduce the statewide mute swan population growth to zero by 2016. A longer-term goal is to reduce Michigan's mute swan population to less than 2,000 by 2030.
What can I do if I want to remove mute swans on my property?
The DNR will issue landowners permits to remove mute swans and/or their nests and eggs. Contact your local DNR office and they can provide more information.
Permits for removal of mute swans or mute swan nests/eggs may be issued at any time by the DNR for the following: public health, safety, or welfare; native and endangered/threatened species concerns; and stabilization of population levels/prevention of new populations.
What can I do if there is an aggressive mute swan on my water body?
Contact your local DNR office. Mute swans and their eggs and nests may be taken on public or private property by DNR personnel, local and state police agencies, and under a DNR permit to local units of government, private citizens or a contracted nuisance animal control firm at any time if they are endangering or about to endanger public health, safety or welfare.
Is there a hunting season for mute swans in Michigan?
No. Mute swans are protected under state law and can only be removed under a permit issued by the DNR. There are no plans to create a swan hunting season.
How can I get a permit?
If you have mute swans on your property and wish to receive a permit to remove them or their nests and eggs, contact your local DNR office.
If you have multiple landowners on your water body, you must submit a petition signed by 70 percent of the lakeshore owners or 70 percent of the shoreline ownership; or provide a resolution from an elected local government official (township, city, etc.) who represents the property owners on the body of water that approves mute swan control for that site.
Do other conservation groups support mute swan control?
There are many conservation groups that support the DNR's drastic reduction of mute swan numbers because of the negative impacts mute swan have native birds and wetland habitat. National Audubon Society, Michigan Audubon Society, the American Bird Conservancy and Ducks Unlimited are just a few organizations that have endorsed the reduction of mute swan populations.
Why not just destroy mute swan nests and eggs instead of killing adult swans?
The quickest, and most humane, way to drastically reduce the mute swan population is to decrease adult survivorship by killing adult birds. Because of the mute swan's high reproductive potential and long life span, alternative control methods such as nest and egg destruction to decrease recruitment of young, are not very effective or efficient in reducing populations.
The DNR and permittees have been destroying mute swan nests and eggs, and this has slowed the rate of population growth. The destruction of mute swan nests and eggs will continue and may be the optimal choice for some sites because of social considerations. However, nest and egg destruction alone will not lead to a significant reduction in mute swan numbers.
Why can't the DNR relocate mute swans, both in and outside of Michigan?
The Michigan DNR has a goal to drastically reduce the mute swan population in the next 20 years in order to protect native wildlife species and wetland habitats, as well as minimize dangerous conflicts with humans. Capture and relocation of mute swans would not only fail to solve the immediate problem, but may actually compound it. All of the feral populations of mute swans in North America originated from either the intentional release or accidental escape of mute swans in captivity. Given this history, it would be irresponsible to relocate mute swans to areas where they are not currently present. Likewise, it would not be responsible for the DNR to attempt to solve our mute swan problem by relocating them to other states, either increasing existing populations or expanding the current range of the mute swan, which is already far too large.
What is the Mute Swan Forum?
In 2010, the DNR formed a Mute Swan Forum to discuss mute swan management activities in Michigan. The forum included a diverse group of organizations and agencies such as Ducks Unlimited, Michigan Audubon Society, Friends of the Detroit River, Kellogg Biological Station of Michigan State University, Rouge River Bird Observatory of the University of Michigan, Michigan Lake and Stream Association, Michigan Humane Society and the Detroit Zoological Society. The Mute Swan Forum agreed that increased actions needed to be taken to address the exponential growth of the mute swan population to protect the natural resources of this state.
What will happen if we don't do anything about mute swans?
Mute swans have a tremendous reproductive capacity and few natural predators. Without swift action, the DNR predicts that mute swan numbers could reach over 24,000 in just five years (by 2015). If this happened, Michigan's native wildlife and wetlands would suffer, and there would be unacceptable levels of conflicts with people.
Aren't mute swans legally protected under federal law?
No. Mute swans are not federally protected. Federal protection was removed by the Migratory Bird Treaty Reform Act in 2004 because mute swans are not native to the United States. Therefore, the regulation of mute swans is the exclusive jurisdiction of the state, and mute swans are protected under Michigan law. The DNR allows the removal of mute swans and their nests and eggs through issuance of permits.
What is the DNR doing to control mute swan numbers?
The DNR has a Mute Swan Management and Control Policy and Procedures that outlines both short- and long-term population goals for mute swans in Michigan. Management of mute swans on both public and private lands is covered by these procedures, including issuance of permits for removal of mute swans (humane euthanasia) and their nests and eggs. DNR staff works closely with landowners to assist them in the permitting process and removal of mute swans.
On lands managed by the DNR (including state game and wildlife areas, state park and recreation areas, and state forest lands) there is a goal to eliminate mute swans and manage for native wildlife species and their habitats. DNR personnel are authorized to take mute swans and their nests and eggs.
The DNR is working on developing and improving a number of outreach and education products to inform Michigan's citizens about mute swans and management goals.
The DNR continues to monitor mute swan numbers throughout the state through a mid-winter waterfowl count conducted in early January, then by the Michigan Spring Breeding Waterfowl Survey conducted each April-May.
Do other states manage mute swan populations?
Yes. Most states in the eastern U.S. and mid-western U.S. control mute swans at some level. Most of these states have relatively small mute swan populations and use control activities to keep populations from increasing. Several states have mute swan management plans. Several states do not protect mute swans at all.
Can the DNR kill mute swans on private lands?
Only if the landowners have given the DNR permission and requested mute swan removal. In most cases, the DNR will issue the site a permit for removal of mute swans. Permittees can be authorized to conduct control activities themselves or contract a licensed nuisance animal control firm. DNR staff is not likely to conduct mute swan control activities on private land unless it is removal of aggressive mute swans.
Is the DNR going to kill all of the mute swans?
No. The DNR has a long-term goal to reduce the population to a manageable level of less than 2,000 by 2030.
Why is the DNR just now worried about controlling mute swans?
Concerns over the expanding population of non-native mute swans were first expressed by the DNR in the 1960s and that concern continues today. Mute swan management activities have been taking place for decades at varying levels.