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  • Myocastor coypus (Photo: Aurelio Perrone, Applied Ecology Research Center, Turin, Italy)
  • Myocastor coypus (Photo: Aurelio Perrone, Applied Ecology Research Center, Turin, Italy)
  • Myocastor coypus (Photo: Aurelio Perrone, Applied Ecology Research Center, Turin, Italy)
  • Myocastor coypus (Photo: Aurelio Perrone, Applied Ecology Research Center, Turin, Italy)
  • Myocaster coypus (Photo: J. Patrick Fischer, Wikimedia Commons)
  • Myocaster coypus (Photo: Peleg, Wikimedia Commons)
  •  Myocaster coypus (Photo: Jos� Reynaldo da Fonseca, Wikimedia Commons)
  • Myocaster coypus (Photo: Philippe Amelant, Wikimedia Commons)
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Common name
ragondin (French), Sumpfbiber (German), Biberratte (German), coypu (English), nutria (English), ratão-do-banhado (Portuguese, Brazil), coipù (Spanish)
Synonym
Similar species
Ondatra zibethicus
Summary
Myocastor coypus (coypu) is a large semi-aquatic rodent which originated from South America. However, due to escapes and releases from fur farms there are now large feral populations in North America, Europe and Asia. Their burrows penetrate and damage river banks, dykes and irrigation facilities. Myocastor coypus' feeding methods lead to the destruction of large areas of reed swamp. Habitat loss caused by coypus impacts plant, insect, bird and fish species.
Species Description
Myocastor coypus (coypu) is a large rodent (5-9kg; 40-60cm body; 30-45cm tail), superficially rat-like, pelage brown and yellow-brown in colour with a cylindrical tail. It has webbed hindfeet, with a footprint up to 15cm long, imprints of the web is often visible; incisors are prominent and bright orange-yellow (unlike rats which are yellow-brown), with white marks on muzzle (Woods et al. 1992, Carter and Leonard 2002). Faeces cylindrical, up to 70mm long, with fine longitudinal striations (LeBlanc, 1994).
Notes
Myocastor coypus (coypu) prefer habitats near the water, animals are rarely observed over 100m away from river. Severe winter could reduce reproductive success and adult survival.
Lifecycle Stages
Myocastor coypus (coypu) breed throughout the year; post-partum oestrus. Sexual maturity 3-10 months. Gestation 127-138 days. Mean litter sizes 5-6 (2-9), prenatal embryo losses are common during cold winter and in females in poor health condition. Woods et al. 1992)
Uses
Myocastor coypus (coypu) are valued as a source of fur (Carter and Leonard 2002) and have been used as a meat source. Coypu provides prey for alligators and other native predators in some areas
Habitat Description
Myocastor coypus (coypu) are generally found near permanent water, particularly reed beds and swamp/marsh. Also found in rivers, streams, lakes, ponds and brackish marsh in coastal areas.
Reproduction
Placental. Sexual. Significant relationship between winter severity and female reproduction in the following spring. Prenatal embryo losses are high until 13-14 weeks of gestation. Sexual maturity 3-10 months. Gestation 127-138 days. Litter size 2-9; prenatal embryo losses are common during cold winter and in females in poor health condition. (Woods et al. 1992, Genesis Laboratories, Inc. 2002)
Nutrition
Herbivorous, Myocastor coypus (coypu) eat wetland plants and crops. Selective feeding causes massive reduction in reed swamp. Occasional feeding on freshwater mussels are reported. It practices coprophagy. (Woods et al. 1992, Carter and Leonard 2002, Genesis Laboratories, Inc. 2002)
Pathway
Fur farms, introduced for fur exploitation.

Principal source: Woods, C.A., Contreras, L., Willner-Chapman, G. and Whidden, H.P. 1992. Myocastor coypus. Mammalian Species 398: 1-8.,
Carter, J. and Leonard, B. 2002. A review of the literature on the worldwide distribution, spread of and efforts to eradicated the coypu (Myocastor coypus). Wildlife Society Bulletin 30: 162-175.

Compiler: Dr. Sandro Bertolino, DIVAPRA Entomology and Zoology, University of Turin, Italy & IUCN/SSC Invasive Species Specialist Group (ISSG)

Review:

Publication date: 2008-04-13

Recommended citation: Global Invasive Species Database (2024) Species profile: Myocastor coypus. Downloaded from http://iucngisd.org/gisd/species.php?sc=99 on 08-12-2024.

General Impacts
Myocastor coypus (coypu) burrows undermine the banks of rivers and dykes causing instability (Carter and Leonard, 2002). Feeding on rhizomes and young shoots of marsh plants leads to plant community breakdown and can lead to erosion in coastal habitats (LeBlanc, 1994). Coypu feeding on sea oat rhizomes in Mississippi barrier islands have led to sand dune erosion in these important habitats (GSMFC 2005).

At high densities coypu are able to convert marshland to open water by feeding on plants. Habitat destruction caused by coypu threatens rare marshland species of bird, fish and invertebrates. In Italy coypu have caused breeding whiskered tern (Chlidonias hybrida) to decline by largely destroying the cover of water-lilies Nymphaea in Valli di Argenta a designated IBA (Important Bird Area). The habitats of two national treasure species in Japan - a critically endangered dragon fly (see Libellula angelina in IUCN Red List of Threatened Species) and a fish the vulnerable deep-bodied bitterling (see Acheilognathus longipinnis in IUCN Red List of Threatened Species) (Shirow Tatsuzawa, pers. Comm.) are threatened by coypu.

Coypu also feed on agricultural crops (Carter and Leonard 2002) including sugarcane, alfalfa and root crops (Woods et al. 1992)

Management Info
Feral populations of coypu are managed by shooting and trapping. Eradication is preferable for small to medium size populations but some level of control is essential in most cases if eradication is not feasible . High fur prices can help encourage sufficient hunting to control populations (Carter and Leonard 2002). In times of high fur prices little damage was observed to wetlands in Louisiana, USA (Marx et al. 2003). In 2002 a bounty system existed in Louisiana. That year a $12.5 million investment resulted in 342 trappers returning 300,000 tails over a 4 month season. Animals were shot or trapped and carcasses were either retained and sold as pelts or disposed of in the wetlands (Marx et al. 2003). Coypu have been eradicated from a number of states in the USA and are classed as pests in countries throughout the world (Carter and Leonard, 2002). A population of around 6000 coypu (Genovesi, 2005) was eradicated from East Anglia, UK in a campaign using cage traps. 24 trappers were employed for 8 years at a cost of £2.5 million (Gosling, 1989). An eradication was proposed for a small lake in Sicily but opposition by the World Wildlife Fund (WWF) prevented the eradication taking place (Genovesi, 2005). An unsuccessful attempt was made to use pythons (Python rebae) as a biocontrol for coypu in Lake Navaisha in Keya (Harper et al. 1990)
Countries (or multi-country features) with distribution records for Myocastor coypus
Informations on Myocastor coypus has been recorded for the following locations. Click on the name for additional informations.
Lorem Ipsum
Location Status Invasiveness Occurrence Source
Details of Myocastor coypus in information
Status
Invasiveness
Arrival date
Occurrence
Source
Introduction
Species notes for this location
Location note
Management notes for this location
Impact
Mechanism:
Outcome:
Ecosystem services:
Impact information
Myocastor coypus (coypu) burrows undermine the banks of rivers and dykes causing instability (Carter and Leonard, 2002). Feeding on rhizomes and young shoots of marsh plants leads to plant community breakdown and can lead to erosion in coastal habitats (LeBlanc, 1994). Coypu feeding on sea oat rhizomes in Mississippi barrier islands have led to sand dune erosion in these important habitats (GSMFC 2005).

At high densities coypu are able to convert marshland to open water by feeding on plants. Habitat destruction caused by coypu threatens rare marshland species of bird, fish and invertebrates. In Italy coypu have caused breeding whiskered tern (Chlidonias hybrida) to decline by largely destroying the cover of water-lilies Nymphaea in Valli di Argenta a designated IBA (Important Bird Area). The habitats of two national treasure species in Japan - a critically endangered dragon fly (see Libellula angelina in IUCN Red List of Threatened Species) and a fish the vulnerable deep-bodied bitterling (see Acheilognathus longipinnis in IUCN Red List of Threatened Species) (Shirow Tatsuzawa, pers. Comm.) are threatened by coypu.

Coypu also feed on agricultural crops (Carter and Leonard 2002) including sugarcane, alfalfa and root crops (Woods et al. 1992)

Red List assessed species 6: CR = 1; VU = 3; LC = 2;
Locations
ITALY
JAPAN
NETHERLANDS
UNITED KINGDOM
Mechanism
[1] Predation
[4] Grazing/Herbivory/Browsing
[1] Rooting/Digging
Outcomes
[2] Environmental Ecosystem - Habitat
  • [2] Reduction in native biodiversity
[6] Socio-Economic
  • [4] Damage to agriculture
  • [1] Human nuisance 
  • [1] Damage to infrastructures
Management information
Feral populations of coypu are managed by shooting and trapping. Eradication is preferable for small to medium size populations but some level of control is essential in most cases if eradication is not feasible . High fur prices can help encourage sufficient hunting to control populations (Carter and Leonard 2002). In times of high fur prices little damage was observed to wetlands in Louisiana, USA (Marx et al. 2003). In 2002 a bounty system existed in Louisiana. That year a $12.5 million investment resulted in 342 trappers returning 300,000 tails over a 4 month season. Animals were shot or trapped and carcasses were either retained and sold as pelts or disposed of in the wetlands (Marx et al. 2003). Coypu have been eradicated from a number of states in the USA and are classed as pests in countries throughout the world (Carter and Leonard, 2002). A population of around 6000 coypu (Genovesi, 2005) was eradicated from East Anglia, UK in a campaign using cage traps. 24 trappers were employed for 8 years at a cost of £2.5 million (Gosling, 1989). An eradication was proposed for a small lake in Sicily but opposition by the World Wildlife Fund (WWF) prevented the eradication taking place (Genovesi, 2005). An unsuccessful attempt was made to use pythons (Python rebae) as a biocontrol for coypu in Lake Navaisha in Keya (Harper et al. 1990)
Locations
Management Category
Prevention
Eradication
Control
Unknown
Bibliography
24 references found for Myocastor coypus

Management information
Bomford, M., 2003. Risk Assessment for the Import and Keeping of Exotic Vertebrates in Australia. Bureau of Rural Sciences, Canberra.
Summary: Available from: http://www.feral.org.au/wp-content/uploads/2010/03/PC12803.pdf [Accessed August 19 2010]
Carter, Jacoby., 2007. Worldwide Distribution, Spread of, and Efforts to Eradicate the Nutria (Myocastor coypus) USGS National Wetlands Research Center
Summary: Website contains information about the introduced range of the coypu broken up by continent.
Available from: http://www.nwrc.usgs.gov/special/nutria/index.htm [Accessed 29 January 2008]
Carter, J. and Leonard, B. P. 2002. A review of the literature on the worldwide distribution., spread of, and efforts to eradicate the coypu (Myocastor coypus) Source. Wildlife Society Bulletin. 30(1): 162-175.
Fasham, M; Trumper, Kate., 2001. Review of non-native species legislation and guidance Department for Environment, Food & Rural Affairs
Summary: Available from: http://www.defra.gov.uk/wildlife-pets/wildlife/management/non-native/documents/review-report.pdf [Accessed 12 March 2010]
Genesis Laboratories, Inc. 2002. Report prepared for the Lousiana Department of Wildlife and Fisheries. 155pp.
Summary: Thorough review of biology and natural history, control and socioeconomic and cultural effects of coypu in Louisiana
Genovesi, P. 2005. Eradications of invasive alien species in Europe: a review. Biological Invasions. 7 (1): 127-133.
Summary: This paper gives details about the eradications of invasive species from Europe.
Gosling, L. M. 1989. Extinction to order. New Scientist, 4 march 1989: 44-49.
Summary: Results of the eradication campaign in England.
Gosling, L. M. and Baker, S. J. 1987. Planning and monitoring an attempt to eradicate coypus from Britain. Symposia of The Zoological Society of London 58: 99-113.
Summary: Populations simulations were used to help plan a campaign to eradicate feral coypus.
Gosling, L. M., Baker, S. J. and Clarke, C. N. 1988. An attempt to remove coypus (Myocastor coypus) from a wetland habitat in East Anglia. Journal of Applied Ecology 25: 49-62.
Summary: A trial was carried out to test wether it was possible to eradicate coypu using cage trapping.
Harper, D.M., Mavuti, K.M. and Muchiri, S.M., 1990. Ecology and management of Lake Naivasha, Kenya, in relation to climatic change, alien species introduction, and agricultural development. Environmental Conservation 17: 328-336.
Summary: Information about failed attempt to eradicate coypu using pythons (Python rebae)
LeBlanc, Dwight J. 1994. Nutria Prevention and control of wildlife damage. (Eds) Scott E. Hygnstrom Robert M. Timm & Gary E. Larson
Summary: Concise review of coypu damage and control methods, focussing on Louisiana
Available from: http://www.ces.ncsu.edu/nreos/wild/pdf/wildlife/NUTRIA.PDF [Accessed 21 January 2008]
Marx, J., Mouton, E., Linscombe, G. 2003. Nutria harvest distribution 2002-2003 And A survey of nutria herbivory damage in coastal Louisiana in 2003. Unpublished report by Fur and Refuge Division, Louisiana Department of Wildlife and Fisheries.
Summary: Hisrory of nutria colonisation of Louisiana. Also contains a survey of damage to wetlands caused by nutria and infrotmation about the 2003 nutria harvest including a breakdown of different hunting methods in different habitats
Tatsuzawa, Shirow. Department of Regional Science, Hokkaido University, Japan.
Summary: Interview at ISSG HQ. Auckland, 19 March 2004.
General information
Abbas, A. 1991. Feeding strategy of coypu (Myocastor coypus) in central western France. Journal of Zoology, London, 224: 385-401.
Summary: Feeding strategy of coypu and ability to colonize new habitats
Borgnia, M., Galante, M. L. and Cassini, M. H. 2000. Diet of the coypu (Nutria, Myocastor coypus) in agro-systems of Argentina Pampas. Journal of Wildlife Management 64(2): 354-361.
Summary: Diet composition and food selection of coypu in three riparian habitats.
CONABIO. 2008. Sistema de informaci�n sobre especies invasoras en M�xico. Especies invasoras - Mam�feros. Comisi�n Nacional para el Conocimiento y Uso de la Biodiversidad. Fecha de acceso.
Summary: English:
The species list sheet for the Mexican information system on invasive species currently provides information related to Scientific names, family, group and common names, as well as habitat, status of invasion in Mexico, pathways of introduction and links to other specialised websites. Some of the higher risk species already have a direct link to the alert page. It is important to notice that these lists are constantly being updated, please refer to the main page (http://www.conabio.gob.mx/invasoras/index.php/Portada), under the section Novedades for information on updates.
Invasive species - mammals is available from: http://www.conabio.gob.mx/invasoras/index.php/Especies_invasoras_-_Mam%C3%ADferos [Accessed 30 July 2008]
Spanish:
La lista de especies del Sistema de informaci�n sobre especies invasoras de m�xico cuenta actualmente con informaci�n aceca de nombre cient�fico, familia, grupo y nombre com�n, as� como h�bitat, estado de la invasi�n en M�xico, rutas de introducci�n y ligas a otros sitios especializados. Algunas de las especies de mayor riesgo ya tienen una liga directa a la p�gina de alertas. Es importante resaltar que estas listas se encuentran en constante proceso de actualizaci�n, por favor consulte la portada (http://www.conabio.gob.mx/invasoras/index.php/Portada), en la secci�n novedades, para conocer los cambios.
Especies invasoras - Mam�feros is available from: http://www.conabio.gob.mx/invasoras/index.php/Especies_invasoras_-_Mam%C3%ADferos [Accessed 30 July 2008]
Gulf States Marine Fisheries Commission (GSMFC), 2005. Myocastor coypus (Kerr, 1792)
ITIS (Integrated Taxonomic Information System), 2005. Online Database Myocastor coypus
Summary: An online database that provides taxonomic information, common names, synonyms and geographical jurisdiction of a species. In addition links are provided to retrieve biological records and collection information from the Global Biodiversity Information Facility (GBIF) Data Portal and bioscience articles from BioOne journals.
Available from: http://www.cbif.gc.ca/pls/itisca/taxastep?king=every&p_action=containing&taxa=Myocastor+coypus&p_format=&p_ifx=plglt&p_lang= [Accessed March 2005]
Mendelssohn H & Y Yom-Tov, 1987. Eds. Vol 7: Mammals. Plants and Animals of the Land of Israel. Ministry of Defence/The Publishing House, Society for the Protection of Nature in Israel.
Reggiani, G., Boitani, L. and De Stefano, R. 1995. Population dynamics and regulation in the coypu Myocastor coypus in central Italy. Ecography 18: 138-146.
Summary: Demographic parameters of a coypu population in Mediterranean climate.
Reggiani, G., Boitani, L., D Antoni, S. and De Stefano, R. 1993. Biology and control of the coypu in the mediterranean area. Suppl. Ric. Biol. Selvaggina XXI: 67-100.
Summary: Biology and regulation factors of coypu population in mediterranean habitats.
Willner, G. R., Chapman, J. A. and Pursley, D. 1979. Reproduction, physiological responses, food habits, and abundance of nutria on Maryland marshes. Wildlife Monograph 65: 43.
Summary: Study on feeding strategies, population dynamics and adaption of coypus.
Woods, C.A., Contreras, L., Willner-Chapman, G. & Whidden, H.P. 1992. Myocastor coypus. Mammalian Species 398: 1-8.
Summary: Detailed taxonomic information about the species. Map of original native range. Information about breeding, feeding and general impacts. Mainly focussed on native range, some mention of impacts and management in introduced range.
Contact
The following 3 contacts offer information an advice on Myocastor coypus
Bertolino,
Sandro
Myocastor coypus, Sciurus carolinensis
Organization:
DIVAPRA Entomology & Zoology, University of Turin
Address:
Via L. da Vinci 44, 10095 Grugliasco (TO), Italy
Phone:
+39 0116708677
Fax:
+39 0116708586
Gosling,
Morris
Myocastor coypus (leader of the eradication programme of the coypu in England) - United Kingdom
Organization:
Evolution and Behaviour Research Group, Department of Psychology
Address:
Ridley Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK
Phone:
+44 191 2225232
Fax:
+44 191 2225622
Tatsuzawa,
Shirow
Organization:
Department of Regional Science, Hokkaido University.
Address:
N10, W7, Kita-ku, Sapporo 060-0810, Japan
Phone:
+81-11-706-3053
Fax:
+81-11-706-3053
Myocastor coypus
ragondin, Sumpfbiber, Biberratte, coypu, nutria, ratão-do-banhado, coipù
Date assessed
Year published
Eicat category
Justification for EICAT assessment
Confidence rating
Mechanism(s) of maximum impact
Countries of most severe impact
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Contributors
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Recommended citation
(2024). Myocastor coypus. IUCN Environmental Impact Classification for Alien Taxa (EICAT).