It was like a twisted fairy tale. We had journeyed to Stratford, Ontario, to see the Shakespeare festival, but walking along the Avon River (yes, they really call it that), we were startled by the large number of Mute Swans. Turns out, it wasn’t a natural accumulation. Town representatives thought the birds were a good representation of Elizabethan England and actually released more into the River. Not only that, but they “over-wintered” their birds, keeping them in a heated enclosure until spring rolled around. The “swan release” in April is a major tourist attraction, as the swans are herded along a tourist-lined street!
Stratford’s response is not unlike a lot of cities. The graceful, quiet Mute Swans have been a symbol of elegance and love since the middle ages, and many parks in this country have them, despite their European origin. But like the Starling and the House Sparrow, bringing over “Shakespeare’s birds” has been a mixed blessing.
Like those other birds, Mute Swans have found an open niche in America. While we probably had large swans resident in the Midwest (most likely Trumpeters), they were hunted to extinction quickly, and their niche of deep-water grazer went largely unfilled until Mute Swans were brought over to grace our parks. They started by escaping into the wild in the Northeast, but the Midwest has seen an even bigger growth of their feral population. Parts of Michigan have large numbers, including lakes and marshes around Detroit and all along the Lake Michigan coast (https://www.mucc.org/the-not-so-silent-invasive-mute-swan . They seem to be quite able to survive Midwest winters without any human help.
Why should this matter? The problem is three-fold: first Mute Swans eat a lot – up to 8 pounds of aquatic vegetation a day – so that large numbers of them can quickly alter the ecology of a pond or marsh, truncating local food webs. Second, the big swans don’t really have any natural predators in the U.S.. They nest in remote parts of marshes, and their aggressive nature probably discourages some predators from attacking their cygnets. Finally, Mute Swans are very territorial during the nesting season. These big swans will chase all sorts of other waterfowl away from their nesting territories, basically creating a no-feed zone against other water birds. Coots, Mallards, Pintails, Canada Geese, even humans in canoes – all will be attacked by hissing, flapping Mute Swans if they intrude on their nesting territory.
How can we control mute swans? Some places start early, trapping the adults or addling the eggs. In the Pacific Northwest, the states of Washington and Oregon have been waging a steady war on the big swans, using all of these tricks to cull their population, with some success. The birds’ urban haunts makes hunting a tricky proposition, but California has recently opened a season on them (https://www.pressdemocrat.com/2025/10/22/californians-shoot-swans-year-round/ ), and several other states are considering doing the same. They can be ‘culled’ as nuisance animals in most Midwestern states, but no hunting season is in place yet.
One trick might be to use Swan Decoys. The birds are territorial enough that a few well-placed decoys might discourage young ones from setting up shop in a marsh or lake. Think of it as the reverse of the normal use of decoys. Locally, such a tactic might be inadvertently at work at Watermark Lake in Grandview, where swan decoys have been placed, probably to scare off large Canada Goose flocks. I recently watched a few young Mute Swans avoid the decoys, swimming on the far side of the large lake, eventually abandoning it. This was odd, given that Mute Swans congregate in large winter flocks in Michigan; perhaps the decoys didn’t look ‘Mute’ enough. This is also quite different from the response of breeding adults, which would probably have attacked the decoys. It seems weird that plastic swans (probably imported from China) might be a potential tool to control live swans imported from Europe.