Management Information
The population size of introduced Mustela vison (American mink) in some countries is so large that that complete eradication, without re-invasion from neighbouring countries or from fur farm escapes, is thought to be virtually impossible (CCS Undated). Detailed knowledge of population sizes and distribution is lacking for most countries in which American mink have established. In the UK, mink are widespread along waterways and around the coast, and the population size has been estimated at over 110,000 (± 55,000; source: JNCC). However, there have been successful mink eradication programs on some islands where re-invasion is easier to control and seabirds have re-colonised nesting sites following mink control in Scotland. A proposal to eradicate mink from the Western Isles in Scotland by Central Science Laboratories (York) and Scottish Natural Heritage is currently being funded by the EU and other countries are addressing the feasibility of carrying out similar eradication schemes (Moore et al. 2003). Macdonald and Harrington (2003) suggest a holistic approach to mink management, involving mink removal, habitat restoration, and the recovery of native competitors. It is necessary to ask whether control can be achieved on any geographical scale, how long term the effects will be, and what the costs would be in terms of either money or animal welfare (Reynolds et al. 2004). The return of the larger otter could be an important component of mink control in the UK as otters are hostile and detrimental towards the American mink (Macdonald and Harrington 2003). In Denmark the focus has been on prevention of mink escape from farms. In Finland, dogs are used to locate the mink and then an air-blaster is used to flush them out. In some areas of conservation importance, or for the protection of livestock, exclusion using mink-proof fences may be the most effective tool. Various types of repellent may also be used (Baker and Macdonald 1999; in Macdonald and Harrington 2003).
Removal of minks by live trapping is a successful method of control. In areas where native mustelids live selective killing procedures may be necessary. Bait containing mink scent glands has been found to be particularly successful (Roy et al. In Press), as mink, like other mustelids, communicate via scent deposition.. The expense of such an operation at a large scale may be prohibitive but this method has been successfully used in the Western Isles (UK), Belarus and on Hiiumaa Island in Estonia (where the mink was eradicated) (Macdonald and Harrington 2003). Modelling excerises have predicted that 60% of mink removed need to be juveniles or sub-adults in order to significantly impact mink numbers. The timing of mink control is also important; at the end of summer mink that remain are sometimes regarded as a "doomed surplus" and thus their removal would entail a waste of culling effort. Please follow this link for an overview of the management methods adopted for the control of Mustela vison compiled by the ISSG
Location Specific Management InformationArchipelago National Park
A mink control programme has been carried out on the outer archipelago of SW Finland. This has resulted in an increase in numbers of tufted duck, velvet scoter and shelduck (Council of Europe, 2002).
Mink removal from Nauvo, Trunso began in 1992-93. Mink were removed using a tracking hound to find and locate the mink, and an air-blasting device to flush the mink from its refuge. In the initial years, high numbers of mink were removed (up to 63 individuals per year). Five individuals were removed after reinvading in spring and summer in 1996, 1997, 1999 and 2001. The area has been considered mink-free during most breeding seasons of birds (Nordstrom and Korpimaki, 2004).
Mink removal from Korppoo, Uto-Jurmo began in 1998. At least 50 mink were removed between autumn 1998 and spring 2001, and up to two mink have been recorded on islands during the breeding season of birds. Most of the area has been mink free between 1999 and 2001 (Nordstrom and Korpimaki, 2004). Avon catchment
In the Avon catchment, most current mink control is carried out for fisheries management (Reynolds et al., 2004). Benbecula (Western Isles)
The Hebridean Mink Project aims to eradicate the American mink from the Uists and to reduce their numbers in South Harris. This is carried out line trapping and capturing animals at den sites found using dog searches. Live trapping is used as it is the most publicly acceptable, humane and successful technique, and the bait used is mainly fish or fish oil, or scent glands removed from local male mink (Roy et al. In Press). Use of poisons or fumigants was ruled out due to the risks to non-target species (Moore et al., 2003). At the conclusion of this project in March 2006 a total of 532 mink had been caught, 230 in the Uists, and 302 in Harris. In Harris, capture rates are low, with mostly male individuals being caught on the southern and east coast. In North Uist, the trend appears to be towards a female-biased population. The projects also aims to maintain public awareness of the Hebridean Mink Project. Caithness
In 1987, mink farming was prohibited on any island where they were not already present in Scotland, and in Caithness and Sutherland, under The Mink (Keeping) Order, 1987. Cox Is.
A preliminary feasibility study has been carried out for the possible eradication of American mink and raccoons from Cox and Lanz Island. Both Cox and Lanz Island are considerably larger than any island where mustelids have previously been eradicated. Both islands would need to be eradicated simultaneously to prevent reinvasion, as they lie only 1100m apart. Denmark
The annual mink bag has increased from less than 1000 in the 1970s to 7000-8000 in the past five years.
Escaped fur animals which are not recaptured within two months are considered game, and hence can be hunted/controlled throughout the year. A recent government order placed restrictions on mink farmers in an attempt to minimise farm escapes. Dungeness
Mink control is an established policy on several nature reserves in the UK, including Dungeness. England
Section 14 of the Wildlife and Countryside Act 1981 prohibits release or escape of American mink into the wild (Macdonald et al., undated), and fur farming is now outlawed (Fur Farming (Prohibition) Act 2000; in Reynolds et al., 2004). In England and Wales, mink have been controlled using three main methods (Macdonald et al., undated): trapping, hunting with hounds on foot, and shooting. Trapping (killing or live capture traps) is the main method used. In the 1960s, the Ministry of Agriculture, Fisheries and Food trapped over 5000 mink in England and Wales, with a similar effort occurring in Scotland by the Department of Agriculture. By the mid 1970s, the attempt was seen as futile and was abandoned. More recently, trapping is used as a conservation tool at water vole sites, as well as by farmers, gamekeepers, angling clubs etc. Hunting with hounds was also widespread. An estimated 400-1400 mink were killed by registered minkhound packs annually (many of which previously hunted otters prior to this species' protection), until hunting with dogs was made illegal in 2005 in England and Wales. Conservationists believe that mink hunting has the potential to cause disturbance to other wildlife, such as otter. Shooting is mostly ad hoc, carried out by farmers and gamekeepers. The majority of mink are killed during winter or in autumn when juveniles are dispersing. It is unlikely that any current method of control in the UK could achieve eradication, and it is recommended that mink control be prioritised in areas of high conservation concern, such as areas with populations of water voles. Macdonald and Strachan (1999; in Macdonald et al., undated) recommend that control is carried out between January and April in the UK, to target breeding females. In lowland England, the recovery of the otter may work against the mink, but recovery of the European polecat (Mustela putorius) will make mink trapping more problematic. Finland
Mink control has been carried out in Finland's Archipelago National Park. Gorodok Nature Reserve
Trapping of American mink in Gorodok Nature Reserve was initiated in 1992/1993, to halt the decline of European mink (Mustela lutreola). In a 20 x 30 km area, 70-80 American mink were removed in the first year - an estimated 80% of the local population. In 1998, a further 73 American mink were captured, and between then and 2001 another 40 have been removed. Gwent Levels
Mink control is an established policy on several nature reserves in the UK, including Gwent Levels. Hiiumaa Island
M. vison was eradicated from Hiiumaa Island in 1998. The estimated population size was 50 (Macdonald et al. 2002). A variety of traps were used with varying degrees of success: initially the "Conibear-type" trap was used with commercially produced mink lures, then locally-built wooden live traps with local fish bait, but neither had great success rates. The eradication was successfully completed using modified leg-hold traps. The endangered European mink (Mustela lutreola) has since been reintroduced (MacDonald and Harrington, 2003). Iceland
In Iceland, the first law which stated that American mink should be eradicated was passed in 1949 (Hersteinsson, 1999; in Hammershoj, 2004). Local authorities were charged with employing hunters to kill mink within the community boundaries, but despite these efforts, feral populations of mink are still present throughout Iceland (Hammershoj, 2004). Mink control is an established policy to protect breeding seabird populations in some areas (Reynolds et al. 2004). Lanz Is.
A preliminary feasibility study has been carried out for the possible eradication of American mink and raccoons from Cox and Lanz Island. Both Cox and Lanz Island are considerably larger than any island where mustelids have previously been eradicated. Both islands would need to be eradicated simultaneously to prevent reinvasion, as they lie only 1100m apart. Minsmere
Mink control is an established policy on several nature reserves in the UK, including Minsmere. Pagham Harbour
Mink control is an established policy on several nature reserves in the UK, including Pagham Harbour. Patagonia (Chile)
The American mink is the subject of a dispersal control programme in Chilean Patagonia (Ruiz et al. 1996; in Jaksic et al. 2002), and the potential for mink fur to be used in handcrafts is being investigated (Jaksic et al. 2002). Romney Marshes
Mink control is an established policy on several nature reserves in the UK, including Romney Marshes. Rye Harbour
Mink control is an established policy on several nature reserves in the UK, including Rye Harbour. Scotland
Section 14 of the Wildlife and Countryside Act 1981 prohibits release or escape of American mink into the wild (Macdonald et al., undated), and fur farming is now outlawed (Fur Farming (Prohibition) Act 2000; in Reynolds et al., 2004). In England and Wales, mink have been controlled using three main methods (Macdonald et al., undated): trapping, hunting with hounds on foot, and shooting. Trapping (killing or live capture traps) is the main method used. In the 1960s, the Ministry of Agriculture, Fisheries and Food trapped over 5000 mink in England and Wales, with a similar effort occurring in Scotland by the Department of Agriculture. By the mid 1970s, the attempt was seen as futile and was abandoned. More recently, trapping is used as a conservation tool at water vole sites, as well as by farmers, gamekeepers, angling clubs etc. Hunting with hounds was also widespread. An estimated 400-1400 mink were killed by registered minkhound packs annually (many of which previously hunted otters prior to this species' protection), until hunting with dogs was made illegal in 2005 in England and Wales. Conservationists believe that mink hunting has the potential to cause disturbance to other wildlife, such as otter. Shooting is mostly ad hoc, carried out by farmers and gamekeepers. The majority of mink are killed during winter or in autumn when juveniles are dispersing. It is unlikely that any current method of control in the UK could achieve eradication, and it is recommended that mink control be prioritised in areas of high conservation concern, such as areas with populations of water voles. Macdonald and Strachan (1999; in Macdonald et al., undated) recommend that control is carried out between January and April in the UK, to target breeding females. A mink control programme is currently underway in Scotland's Western Isles. Scott Is.
A preliminary feasibility study has been carried out for the possible eradication of American mink and raccoons from Cox and Lanz Island. Both Cox and Lanz Island are considerably larger than any island where mustelids have previously been eradicated. Both islands would need to be eradicated simultaneously to prevent reinvasion, as they lie only 1100m apart. Somerset Levels
Mink control is an established policy on several nature reserves in the UK, including Somerset Levels. State Forest District (Thy)
209 mink were killed during a three-year control scheme between 1998 and 2000 in Thy State Forest District. There were also a number of non-target deaths, including other mustelids such as polecat, as well as rodents and birds. Strumpshaw Fen
Mink control is an established policy on several nature reserves in the UK, including Strumpshaw Fen. Sutherland
In 1987, mink farming was prohibited on any island where they were not already present in Scotland, and in Caithness and Sutherland, under The Mink (Keeping) Order, 1987. United Kingdom (UK)
Section 14 of the Wildlife and Countryside Act 1981 prohibits release or escape of American mink into the wild (Macdonald et al., undated), and fur farming is now outlawed (Fur Farming (Prohibition) Act 2000; in Reynolds et al., 2004). In England and Wales, mink have been controlled using three main methods (Macdonald et al., undated): trapping, hunting with hounds on foot, and shooting. Trapping (killing or live capture traps) is the main method used. In the 1960s, the Ministry of Agriculture, Fisheries and Food trapped over 5000 mink in England and Wales, with a similar effort occurring in Scotland by the Department of Agriculture. By the mid 1970s, the attempt was seen as futile and was abandoned. More recently, trapping is used as a conservation tool at water vole sites, as well as by farmers, gamekeepers, angling clubs etc. Targeting animals during the breeding season between January and April in the UK (Macdonald and Strachan 1999, in Macdonald et al. Undated) or finding them at natal den sites during the summer denning period seems to have the most impact on populations (Moore et al. 2003).
The Game Conservancy Trust (GCT) has developed a mink raft known as a "GCT mink raft" that provides a means of both monitoring and then capturing American mink. It incorporates a moist sandy clay mixture to records footprints of visiting animals. Once a mink is detected managers install traps on the rafts. This system minimises the number of traps and time needed, increasing cost-efficiency and decreasing manpower and traps used. Once mink have been caught, the trap can be removed and the raft returned to ‘detection’ mode. These rafts are already being used by the WildCRU team researching mink control in Oxfordshire. The Universities Federation for Animal Welfare have awarded their first Wild Animal Welfare Award to Dr Jonathan Reynolds of the Game Conservancy Trust, for designing this trap. The award recognised the fact that this trap alleviates and prevents to harm animals in the wild because while many other trapping systems are unselective the GCT mink raft allows mink to be caught whilst minimising the risk of capturing of non-target species.Hunting with hounds was also widespread. An estimated 400-1400 mink were killed by registered minkhound packs annually (many of which previously hunted otters prior to this species' protection), until hunting with dogs was made illegal in 2005 in England and Wales. Conservationists believe that mink hunting has the potential to cause disturbance to other wildlife, such as otter. Shooting is mostly ad hoc, carried out by farmers and gamekeepers. The majority of mink are killed during winter or in autumn when juveniles are dispersing. It is unlikely that any current method of control in the UK could achieve eradication, and it is recommended that mink control be prioritised in areas of high conservation concern, such as areas with populations of water voles, or nature reserves. Macdonald and Strachan (1999; in Macdonald et al., undated) recommend that control is carried out between January and April in the UK, to target breeding females. In lowland England, the recovery of the otter may work against the mink, but recovery of the European polecat (Mustela putorius) will make mink trapping more problematic. A mink control programme is currently underway in Scotland's Western Isles.
In 2003, scientists from Royal Holloway College demonstrated that reed beds could provide water voles with refuge from predation by mink and other mustelids. To investigate the mechanism involved, the researchers radio-tracked mink to monitor their habitat use. Mink generally hunted close to main watercourses and avoided the depths of the reed bed. This finding confirmed the importance of reed beds on the criteria for selecting National Key Sites for water voles (Macdonald and Baker 2005). Wales
Section 14 of the Wildlife and Countryside Act 1981 prohibits release or escape of American mink into the wild (Macdonald et al., undated), and fur farming is now outlawed (Fur Farming (Prohibition) Act 2000; in Reynolds et al., 2004). In England and Wales, mink have been controlled using three main methods (Macdonald et al., undated): trapping, hunting with hounds on foot, and shooting. Trapping (killing or live capture traps) is the main method used. In the 1960s, the Ministry of Agriculture, Fisheries and Food trapped over 5000 mink in England and Wales, with a similar effort occurring in Scotland by the Department of Agriculture. By the mid 1970s, the attempt was seen as futile and was abandoned. More recently, trapping is used as a conservation tool at water vole sites, as well as by farmers, gamekeepers, angling clubs etc. Hunting with hounds was also widespread. An estimated 400-1400 mink were killed by registered minkhound packs annually (many of which previously hunted otters prior to this species' protection), until hunting with dogs was made illegal in 2005 in England and Wales. Conservationists believe that mink hunting has the potential to cause disturbance to other wildlife, such as otter. Shooting is mostly ad hoc, carried out by farmers and gamekeepers. The majority of mink are killed during winter or in autumn when juveniles are dispersing. It is unlikely that any current method of control in the UK could achieve eradication, and it is recommended that mink control be prioritised in areas of high conservation concern, such as areas with populations of water voles. (Macdonald and Strachan 1999; in Macdonald et al., undated) recommend that control is carried out between January and April in the UK, to target breeding females. Western Isles
The Hebridean Mink Project is a five-year nature conservation initiative aimed at eradicating the alien predator, American mink (Mustela Vison) from the islands of North Uist, Benbecula and South Uist, and significantly reduce their numbers in Harris in a bid to protect internationally significant population of ground nesting birds. This five year project is now drawing to a close and efforts are focussed on eradicating mink from the remainder of the Western Isles. The project was set up by a partnership of Scottish Natural Heritage, The Scottish Executive, the Royal Society for the Protection of Birds, Comhairle nan Eilean Siar (the local auhtority for the Western Isles), Central Science Laboratory and Western Isles Enterprise. The total cost of the project was £1.65m.Half of this was from the EU LIFE Nature Fund, a funding organisation that aims to help the protection of 'Natura' sites designated under the EC Habitats and Wild Birds Directives. The remainder of the funding will be provided as follows: £443,000 from Scottish Natural Heritage, £150,000 from The Scottish Executive, £52,000 from RSPB, £100,000 from Comhairle nan Eilean Siar, £42,000 from the Central Science Laboratory, and £35,000 from Western Isles Enterprise.
The project was run with the equivalent of 11 full time posts over a five year period; 10 trappers and a manager. Research work was carried out by a Phd student. The traps used were small cages hidden under turf and bated with fish. They contain the animal but cause no physical harm. Every trap involved in the project was checked at least daily and all mink caught are destroyed humanely using one shot to the head with an airgun.
Mink are also widespread in Lewis and Harris and the long term aim is to remove them entirely from the whole of the Wester Isles. An important part of this project therefore was to assess the mink populations at different densities, and their responses to control, in order to develop a model for determining a possible strategy and the costs of a second phase on Lewis and Harris. Annual surveys and monitoring of breeding bird populations was carried out on North Uist and Benbecula to assess the effects of the control. A community liaison committee has been established to invite participation of local interest groups and those with experience of mink trapping. An information leaflet on the project was produced for distribution on the islands and elsewhere. Press and media coverage was encouraged to raise awareness of the project and its objectives. The findings will be published in scientific literature, and a European Workshop was held at the end of the project to disseminate the results. Wickham Fen
Mink control is an established policy on several nature reserves in the UK, including Wickham Fen.
Management Resources/Links
2. Bonesi, L. and Macdonald, D.W. 2004. Evaluation of sign surveys as a way to estimate the relative abundance of American mink (Mustela vison), Journal of Zoology 262: 65-72.
Summary: This study looks at the use of sign (scats and footprints) as a reliable and efficient method to estimate the relative abundance of the American mink (Mustela vison). 3. Bonesi, L. and Macdonald, D.W. 2004. Impact of released Eurasian otters on a population of American mink: a test using an experimental approach. Oikos. 106: 9-18.
Summary: This paper discusses the results of an experiment releasing otters into areas inhabited by American mink in the United Kingdom. It was found that otters have a dramatic effect on the distribution and density on the mink population. 4. Centre for Conservation Science (CCS)., Undated. Control of North American mink outside their native range. 5. Council of Europe. 2002. Workshop on invasive alien species on European islands and evolutionary isolated ecosystems: Proceedings. Convention on the conservation of European wildlife and natural habitats. Document prepared by the Directorate of Culture and of Cultural and Natural Heritage.
Summary: This document outlines a number of key issues regarding invasive alien species in Europe. 6. Desholm, M., Christensen, T.K., Scheiffarth, G., Hario, M., Andersson, Å., Ens, B., Camphuysen, C.J., Nilsson, L., Waltho, C.M., Lorentsen, S-H., Kuresoo, A., Kats, R.K.H., Fleet, D.M. and Fox, A.D. 2002. Status of the Baltic/Wadden Sea population of the Common Eider Somateria m. mollissima. Wildfowl. 53: 167-203.
Summary: This articles outlines the status of the eider duck population in northern Europe, and outlines possible reasons for an apparent decline, including the presence of American mink. 8. Genovesi, P. 2005. Eradications of invasive alien species in Europe: a review. Biological Invasions. 7 (1): 127-133.
Summary: This paper gives details of the eradications of introduced species in Europe, including the eradication of M. vison from Hiimaa Island in Estonia. 9. Gillies, C. and Williams, D. Undated. Using tracking tunnels to monitor rodents and mustelids.
Summary: This paper gives detailed information about how to use tracking tunnels. 10. Hammershøj, M., 2004.Population ecology of free-ranging American mink Mustela vison in Denmark. PhD thesis – National Environmental Research Institute, Kalø, Denmark. 30 pp. http://afhandlinger.dmu.dk
Summary: This PhD discusses the presence of American mink in Denmark, and outlines some management options. 11. Hebridean Mink Project. Bulletin February 2004.
Summary: This newsletter gives information and news updates on the project which aims to control and eradicate American mink in the Western Isles of Scotland. 12. Hebridean Mink Project. Bulletin May 2004.
Summary: This newsletter gives information and news updates on the project which aims to control and eradicate American mink in the Western Isles of Scotland. 14. Hudson, P. and Cox, R. 1998. Mink problems in the Outer Hebrides: a pilot study, Game Conservancy Annual Review: 133-135. 15. Lariviere, S., Walton, L.R. and Virgl, J.A. 2000. Field anesthesia of American Mink, Mustela vison, using halothane, Canadian Field-Naturalist 114(1): 142-144.
Summary: A look at the use of halothane for the anesthesia of American Mink for capture-recapture operations. 17. Macdonald, D.W., Tattersall, F.H., Johnson, P.J., Carbone, C., Reynolds, J.C., Langbein, J., Rushton, S.P. and Shirley, M.D.F. Undated. Management and control of populations of foxes, deer, hares, and mink in England and Wales, and the impact of hunting with dogs. A report to the committee of inquiry into hunting with dogs.
Summary: This extensive document outlines the history of mink control in the United Kingdom, and gives recommendations for future management options. 19. Nordström, M. and Korpimäki. 2004. Effects of island isolation and feral mink removal on bird communities on small islands in the Baltic Sea. Journal of Animal Ecology. 73: 424-433.
Summary: This paper discusses the results of mink removal from some islands in Archipelago National Park in south-west Finland. 20. Nordstrom, M., Hogmander, J., Laine, J., Nummelin, J., Laanetu, N. and Korpimaki, E. 2003. Effects of feral mink removal on seabirds, waders and passerines on small islands in the Baltic Sea.
Summary: This paper discusses the results of mink removal from some islands in Archipelago National Park in south-west Finland. 21. Proulx, G. and Barrett, M.W. 1991. Evaluation of the Bionic Trap to Quickly Kill Mink (Mustela Vison) in Simulated Natural Environments, Journal of Wildlife Diseases 27(2): 276-280.
Summary: This study tests the effectiveness of the Bionic(R) trap. 22. Reynolds, J.C., Short, M.J. and Leigh, R.J. 2004. Development of population control strategies for mink Mustela vison, using floating rafts as monitors and trap sites. Biological Conservation. 120: 533-543.
Summary: This study looked at various management techniques for American mink in the Avon catchment in the UK, and presented a new method of trapping using rafts. 23. Yamaguchi, N. and Macdonald, D.W. 2001. Detection of Aleutian disease antibodies in feral American mink in southern England, Veterinary Record 149 Abstract (16): 485-488.
Summary: Fourteen of 27 American mink (Mustela vison) trapped in the upper Thames region were positive for anti-Aleutian disease antibodies. This occurrence of the Aleutian disease parvovirus (ADV) in a feral American mink population suggests that it could threaten populations of at least two protected mustelids, the otter (Lutra lutra) and the polecat (Mustela putorius), and may also play a role in the apparent decline of local mink populations in Britain. 24. Yamaguchi, N., Rushton, S. and Macdonald, D.W. 2003. Habitat preferences of feral American mink in the Upper Thames, Journal of Mammalogy 84(4): 1356-1373.
Summary: This study looks at habitat use by members of a wild population of American mink (Mustela vison) that were live trapped and radiotracked year round in the Upper Thames region, United Kingdom. Results Page: 1
|
