Ondatra zibethicus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Rodentia Cricetidae

Scientific Name: Ondatra zibethicus
Species Authority: (Linnaeus, 1766)
Common Name(s):
English Muskrat
Castor zibethicus Linnaeus, 1766

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Linzey, A.V.
Reviewer(s): Amori, G. (Small Nonvolant Mammal Red List Authority) & Tsytsulina, K. (Global Mammal Assessment Team)
A widespread, common, and widely introduced species with no major threats, hence listed as Least Concern.
Previously published Red List assessments:
1996 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: This species occurs in North America, from northern Canada and Alaska south through the United States, except the arid regions of the southwest and Texas, and the Florida peninsula. Introduced to Czech Republic in 1905 in order to establish fur farms, it is now present throughout the Palaearctic, Mongolia, China, northeast Korea, and Honshu Island, Japan. Also introduced in Argentina (Musser and Carleton, 2005).
Countries occurrence:
Canada; United States
Albania; Argentina; Austria; Belarus; Belgium; Bulgaria; Chile; Czech Republic; Estonia; Finland; France; Germany; Gibraltar; Hungary; Italy; Japan; Latvia; Lithuania; Mexico; Moldova; Mongolia; Netherlands; Poland; Romania; Russian Federation; Slovakia; Slovenia; Sweden; Switzerland; Ukraine
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The muskrat is common to abundant in suitable habitats, with average densities of 40 individuals per hectare (Feldhamer, 1999 in Wilson and Ruff, 1999).
Current Population Trend: Stable
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: Muskrats are found in brackish and fresh-water lakes, ponds, streams, rivers, and marshes. Depending on the location, they will either dig burrows into waterside banks, or construct houses of vegitation. Houses are built so that the main chambers are above water level, but can only be entered through underwater tunnels. Separate structures are constructed for feeding and nesting (Feldhamer, 1999 in Wilson and Ruff, 1999). Muskrats exhibit many morphological adaptations for aquatic life, including lips that close behind incisors to allow gnawing under water, partially webbed hindfeet, and the ability to stay submerged for up to 20 minutes. Muskrats are primarily herbivorous, feeding on aquatic vegiation such as cattails and horsetails. During periods of food scarcity, individuals will also consume animal matter such as mussels, turtles, mice, birds, frogs and fish (Wilner et al., 1980)
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): The majority of muskrat mortality is caused by humans. Muskrats are extensively trapped for their pelts, which are of increasing economic value around the world. High population densities of muskrats often result in destruction of local habitat, including damage to river banks caused by burrowing, and the reduction of aquatic vegetation due to over consumption for food and building materials. As a result, muskrats are often treated as a pest species and are trapped, hunted or poisoned to control population levels.

Conservation Actions [top]

Conservation Actions: There are no measures currently in place to protect O. zibethicus. Common and considered "secure" (S5) or "apparently secure" (S3) throughout entire US range. One subspecies of concern: O. Z. ripensis (S2 in Texas). Status in Mexico needs to be assessed.

Classifications [top]

5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable  
5. Wetlands (inland) -> 5.4. Wetlands (inland) - Bogs, Marshes, Swamps, Fens, Peatlands
suitability: Suitable  
5. Wetlands (inland) -> 5.5. Wetlands (inland) - Permanent Freshwater Lakes (over 8ha)
suitability: Suitable  
5. Wetlands (inland) -> 5.7. Wetlands (inland) - Permanent Freshwater Marshes/Pools (under 8ha)
suitability: Suitable  
5. Wetlands (inland) -> 5.14. Wetlands (inland) - Permanent Saline, Brackish or Alkaline Lakes
suitability: Suitable  
5. Wetlands (inland) -> 5.16. Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools
suitability: Suitable  
15. Artificial/Aquatic & Marine -> 15.1. Artificial/Aquatic - Water Storage Areas (over 8ha)
suitability: Suitable  
15. Artificial/Aquatic & Marine -> 15.2. Artificial/Aquatic - Ponds (below 8ha)
suitability: Suitable  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education

Bibliography [top]

Hafner, D. J., Yensen, E. and Kirkland Jr., G. L. 1998. Status survey and conservation action plan - North American Rodents. IUCN/SSC Rodent Specialist Group, Gland, Switzerland.

Musser, G. G. and Carleton, M. D. 2005. Superfamily Muroidea. In: D. E. Wilson and D. A. Reeder (eds), Mammal Species of the World: a geographic and taxonomic reference, pp. 894-1531. The John Hopkins University Press, Baltimore, USA.

Willner, G. R., Feldhamer, G. A., Zucker, E. E. and Chapman, J. A. 1980. Ondatra zibethicus. Mammalian Species 141: 1-8.

Wilson, D.E. and Ruff, S. 1999. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, DC, USA.

Citation: Linzey, A.V. 2008. Ondatra zibethicus. The IUCN Red List of Threatened Species 2008: e.T15324A4513540. . Downloaded on 25 May 2016.
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