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Mute swans: beautiful, invasive, and devastating

Central Michigan University researcher Nicole Wood speaks with Science Around Michigan about invasive mute swans and their impact in Michigan for the #MIspecies campaign. Wood studies the impact of mute swans on Michigan’s valued coastal wetlands. So let’s talk mute swans.

Adrian de Novato: To many people, a swan is a swan is a swan. What’s the difference and why does it matter? Really what I think a lot of people are wondering is why is it considered invasive?

Nicole Wood: To many people it may appear that a swan is a swan is a swan, but Michigan actually has three different swan species that, to the untrained eye, can look very similar. Of the three swan species that inhabit Michigan, two are native, the trumpeter and tundra, and one is invasive, the mute. All three birds are white and the easiest way to tell them apart is by the coloration of their bills. Trumpeter bills are all black and tundra bills are mostly black with a flash of yellow at the base. The bill of the invasive mute swan stands out, as it is almost all orange with a large black knob at the top. Think of mute swan bills as an orange warning flag, marking it as the invasive species, making it easier to recognize.

Image courtesy of the Trumpeter Swan Society.

The mute swan is considered an invasive species for two reasons. The first reason is because the mute swan is a non-native species to Michigan. In fact, it is a non-native species to the entire Western Hemisphere. Mute swans are native to Europe and eastern Asia and were brought over to North America as pets and ornamental birds in the late 1800s to early 1900s. Unfortunately, those birds began to escape and wild populations began to establish themselves.

In 1919, the first documented wild pair of Michigan mute swans were spotted in the northern part of the Lower Peninsula in Charlevoix County.

For a species to be considered invasive, it is not enough for it just to be non-native, the species must also be causing harm to the environment or negatively impacting humans. Research in the Chesapeake Bay area has shown mute swan flocks wiping out entire wetlands of the swans’ preferred food source, submerged aquatic vegetation (SAV), and my own research in the Great Lakes has shown that where mute swans are present there is less SAV.

SAV aren’t just weeds annoying boat owners as they wrap around propellers, SAV is important to the health of a lake. SAV helps regulate the physical make up of lakes, by providing oxygen to the water and reducing the turbidity, helping to make lakes more clear. SAV also provides habitat and food for small fish and invertebrates, making SAV an ideal nursery for many of Michigan’s game and commercial fish. Without SAV, the fish people catch in a lake will be smaller and less numerous. For a state that sees an economic impact well into the billions of dollars from its fisheries, this can be of great concern not only to the environment of Michigan, but also the economy.

Mute Swan
Mute Swan – Courtesy Audubon Society

Mute swans, since their initial introduction to the state of Michigan, have also seen a tremendous growth in their populations. Before the Michigan Department of Natural Resources began taking a more active management role in an attempt to curb the high population growth rate, Michigan had the largest population of mute swans in the US at over 15,000 individuals. Making it even more difficult for the MDNR is that mute swans are a charismatic bird, meaning people like them. Many citizens of Michigan don’t realize that even though a mute swan is a beautiful bird, that its negative impacts on the state can be just as devastating as other common invasive species, such as zebra mussels, sea lamprey, emerald ash borer, etc.

Adrian de Novato: What are the economic and environmental impacts of the mute swan in Michigan?

Nicole Wood: The environmental impacts of mute swans in Michigan, also will impact the economics of Michigan. Mute swans have the potential to damage Michigan’s fisheries. By destroying the SAV habitat that young fish use as nurseries, both Great Lakes and inland lake fish could see a drop in their body sizes and even a drop in their population numbers. Sportfishing in Michigan generates several billion dollars in economic activity, while providing tens of thousands of jobs to Michiganders. Michigan’s commercial fishery generates an additional $40-50 million for the state economy.

Bird watching in Michigan supplies a billion dollar economic impact on the state. Reducing the invasive mute swan will help the threatened trumpeter swan to recover, as more habitat will be available to the native species. Maintaining and restoring the biodiversity of the state is important for protecting the environment. Having a healthy population of trumpeter swans should only help to grow the economic impact of bird watching in Michigan.

Adrian de Novato: If a mute swan moves into my area, shouldn’t I consider that natural?

Nicole Wood: If a mute swan moves into your area, it is not a natural process. Current mute swan movements are a reverberation of the initial human mediated introductions of mute swans to North America.

Adrian de Novato: Why should people care? What can/should people do?

Nicole Wood: The citizens of Michigan should care about the presence of the invasive mute swan, because they can impact the ability of the threatened trumpeter swan to recover back to a healthy statewide population. Mute swans may also impact the health of Michigan’s fisheries, which generate billions of dollars to the state’s economy.

If you see a mute swan on your lake call/email/tweet the Michigan Department of Natural Resources:

(517) 284-9453 (WILD)

The #MIspecies campaign

Help us raise awareness about the serious economic and environmental issues as a result of aquatic invasive species and learn more about how you can help make a difference in your local community at

About Nicole Wood

Nicole Wood is a graduate student at Central Michigan University (CMU). Her thesis work involves the invasive mute swan and their impacts on the ecology of Michigan’s coastal wetlands. Nicole serves on the board of The Wildlife Society – Invasive Species Working Group and is a member of the International Association of Great Lakes Research.

Nicole served as team lead for amphibian and bird surveys as part of a $10 million international Great Lakes basin-wide coastal wetland monitoring project involving several universities. She has managed Michigan bobcat population surveys for the CMU chapter of TWS. Nicole also created and chaired the BioBuds program at CMU, which puts graduate students into elementary schools and teaches young students about wildlife and other science topics.

The use of modern technology in science is one of Nicole’s favorite topics. She likes to use this technology to help discover how species interact with their environments and to help communicate these scientific discoveries with fellow researchers and the general public. The former has lead to research via remote sensing to compliment traditional research methods. The latter has resulted in coordinating the social media of multiple science groups. To find out more about Nicole, her research, and her involvement with science communication (scicomm), visit her website, for links to her multiple scicomm platforms (Twitter, Instagram, Periscope, Snapchat, SoundCloud).


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