Researchers from Loyola, the Sault Ste. Marie Tribe of Chippewa Indians and the University of Connecticut found that muskrats can reduce invasive narrowleaf and hybrid cattails by 71% in a Great Lakes marsh. By cutting stems below the waterline, muskrats create openings that let diverse native plants and animals return. Where muskrats are absent, managers mimicked their cutting and achieved similar reductions, suggesting a practical restoration tool that complements Indigenous ecological knowledge and broader wetland recovery efforts.
Muskrats vs. Invasive Cattails: How a Small Rodent Is Helping Restore Great Lakes Wetlands
Researchers from Loyola, the Sault Ste. Marie Tribe of Chippewa Indians and the University of Connecticut found that muskrats can reduce invasive narrowleaf and hybrid cattails by 71% in a Great Lakes marsh. By cutting stems below the waterline, muskrats create openings that let diverse native plants and animals return. Where muskrats are absent, managers mimicked their cutting and achieved similar reductions, suggesting a practical restoration tool that complements Indigenous ecological knowledge and broader wetland recovery efforts.
15:52, 04.11.2025Environment
Muskrats curb invasive cattails and help revive Great Lakes wetlands
With precise underwater bites, muskrats — large, semi-aquatic rodents with prominent incisors — have emerged as valuable allies for scientists restoring degraded wetlands across the Great Lakes. A Loyola University Chicago-led team, working with the Sault Ste. Marie Tribe of Chippewa Indians and the University of Connecticut, found that muskrats can dramatically reduce invasive cattail cover and promote habitat diversity.
How muskrats change the marsh
Muskrats chew cattail stems below the waterline, severing the plant’s aerial "snorkel" that transports oxygen from the atmosphere to the roots. In dense stands of invasive narrowleaf cattail (Typha angustifolia) and its hybrid with the native broadleaf cattail (Typha x glauca), this feeding behavior creates a patchwork of open water and lower vegetation. Those openings allow plants of different heights to reestablish and provide habitat for fish, invertebrates, birds and amphibians.
“One of the first things that happens is the cattail comes in, outcompetes the very diverse community of native plants,” said Shane Lishawa of Loyola University Chicago. “That prevents plants, aquatic organisms, birds and amphibians from accessing and utilizing these wetlands that are critical for biodiversity across the whole region.”
Evidence from the field
In a freshwater marsh connecting the Munuscong and St. Marys rivers (between lakes Superior and Huron), researchers documented a 71% reduction in invasive hybrid cattails where muskrats were active. The team also observed declines in European frogbit, a floating nonnative plant that thrives among dense cattail stands. These measured effects align with long-standing Indigenous and local ecological knowledge: partners from the Sault Ste. Marie Tribe of Chippewa Indians affirmed muskrats’ role in shaping wetland vegetation.
Cultural context
The common muskrat also appears in Ojibwe creation stories as Wazhashkin, a figure who sacrifices itself to retrieve a small ball of earth that becomes Turtle Island (North America). The study authors highlight this cultural knowledge alongside ecological findings, noting how traditional stories reflect the muskrat’s role in creating habitat for other organisms.
Mimicking muskrats where they are absent
Because muskrat populations have declined regionally and are absent from many wetlands, the researchers tested a human management technique that mimics muskrat cutting by mowing cattail stems below the waterline. That approach produced similar reductions in invasive cattail cover, suggesting a potential restoration tool when muskrats are not present. The team emphasized that such interventions require careful, site-by-site evaluation.
Implications for restoration and policy
Restoration strategies that enlist muskrats, imitate their activity, or combine both could help recover remnant wetlands. Coastal wetlands in the Great Lakes once exceeded 1 million acres, but roughly half have been lost to development, drainage and other human actions. In Illinois alone, as much as 90% of original marsh and swamp has been destroyed. Legal changes such as the U.S. Supreme Court’s 2023 Sackett v. EPA decision have also narrowed federal protections for many inland wetlands, increasing the urgency of local restoration work.
The researchers, who call themselves TeamTypha, recommend further study to track how other species respond to systematic cattail removal, whether by muskrats or human managers. They also note the possibility of relocating muskrats from nuisance areas to degraded wetlands as a restoration tactic, but say any relocation program would need ecological, logistical and ethical review on a case-by-case basis.
Bottom line: Muskrats’ natural cutting of invasive cattails can substantially reduce invasive plant cover, open space for native species, and provide a low-tech, ecology-informed option for wetland restoration when combined with careful management and respect for Indigenous knowledge.
Contact: adperez@chicagotribune.com