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Consumption of freshwater bivalves by muskrats in the Green River, Kentucky

American Midland Naturalist

By:
, , and
DOI: 10.1674/0003-0031-170.2.248

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Abstract

Muskrats (Ondatra zibethicus) are known to prey on freshwater bivalves (mussels and clams) and can negatively impact imperiled mussel species. However, factors that influence muskrat predation on bivalves are poorly understood. We evaluated the feeding ecology of muskrats in the Green River, Kentucky, by using stable isotope analysis of muskrat hair samples and by monitoring bivalve shell deposition at muskrat middens. Bayesian mixing-model analysis of stable isotope δ15N and δ13C ratios revealed that the median muskrat biomass derived from bivalves was 51.4% (5th and 95th percentiles were 39.1 to 63.4%, respectively), a much higher dietary proportion than previously reported. Shell depositions by muskrats at middens decreased with the availability of seasonal emergent vegetation, suggesting that the consumption of animal matter is in response to a scarcity of plant foods, perhaps exacerbated by the altered flow regimes on the Green River. Our results add to the growing body of evidence that muskrats have the potential to impact mussel population growth and recovery in some environments.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Consumption of freshwater bivalves by muskrats in the Green River, Kentucky
Series title:
American Midland Naturalist
DOI:
10.1674/0003-0031-170.2.248
Volume
170
Issue:
2
Year Published:
2013
Language:
English
Publisher:
University of Notre Dame
Contributing office(s):
Leetown Science Center
Description:
12 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
American Midland Naturalist
First page:
248
Last page:
259
Number of Pages:
12
Country:
United States
State:
Kentucky
Other Geospatial:
Mammoth Cave National Park