American Mink

This report is the officially adopted Action Plan for Dublin City. It includes summaries of the known invasive alien species in Dublin City, their geographic distribution and impacts. It also gives guidance to those working in Dublin City on how to address invasive alien species management.

Can simple enrichments enhance caged mink welfare? Pilot data from 756 sub-adults spanning three colour-types (strains)
identified potentially practical enrichments, and suggested beneficial effects on temperament and fur-chewing. Our main
experiment started with 2032 Black mink on three farms: from each of 508 families, one juvenile male-female pair was
enriched (E) with two balls and a hanging plastic chain or length of hose, while a second pair was left as a non-enriched (NE)
control. At 8 months, more than half the subjects were killed for pelts, and 302 new females were recruited (half enriched:
‘late E’). Several signs of improved welfare or productivity emerged. Access to enrichment increased play in juveniles. E mink
were calmer (less aggressive in temperament tests; quieter when handled; less fearful, if male), and less likely to fur-chew,
although other stereotypic behaviours were not reduced. On one farm, E females had lower cortisol (inferred from faecal
metabolites). E males tended to copulate for longer. E females also weaned more offspring: about 10% more juveniles per E
female, primarily caused by reduced rates of barrenness (‘late E’ females also giving birth to bigger litters on one farm),
effects that our data cautiously suggest were partly mediated by reduced inactivity and changes in temperament. Pelt
quality seemed unaffected, but E animals had cleaner cages. In a subsidiary side-study using 368 mink of a second colourtype
(‘Demis’), similar temperament effects emerged, and while E did not reduce fur-chewing or improve reproductive
success in this colour-type, E animals were judged to have better pelts. Overall, simple enrichments were thus beneficial.
These findings should encourage welfare improvements on fur farms (which house 60-70 million mink p.a.) and in breeding
centres where endangered mustelids (e.g. black-footed ferrets) often reproduce poorly. They should also stimulate future
research into more effective practical enrichments.

The purpose of this review is to present the current state of knowledge about the genetics of the American mink (Neovison vison Schreb., 1777) - a species that achieved in the twentieth century an unprecedented ecological success associated with the dynamic development of its economic use. However, despite the large popularity and economic importance of the American mink as a fur animal, and the scale of the problems associated with its introduction beyond the range of natural occurrence, genetic research, particularly molecular genetics and genomics of this species, show relatively little progress. The article contains a comprehensive description of the studies undertaken on the genetics of the species, both in terms of cytogenetics, molecular genetics, genomics, population genetics and phylogenetics. The progress of the genome sequencing project of the American mink is also described as well as its transcriptome annotation. The article also deals with still unexplained and not com...

Can simple enrichments enhance caged mink welfare? Pilot data from 756 sub-adults spanning three colour-types (strains) identified potentially practical enrichments, and suggested beneficial effects on temperament and fur-chewing. Our main experiment started with 2032 Black mink on three farms: from each of 508 families, one juvenile male-female pair was enriched (E) with two balls and a hanging plastic chain or length of hose, while a second pair was left as a non-enriched (NE) control. At 8 months, more than half the subjects were killed for pelts, and 302 new females were recruited (half enriched: ‘late E’). Several signs of improved welfare or productivity emerged. Access to enrichment increased play in juveniles. E mink were calmer (less aggressive in temperament tests; quieter when handled; less fearful, if male), and less likely to fur-chew, although other stereotypic behaviours were not reduced. On one farm, E females had lower cortisol (inferred from faecal metabolites). E ...

The American mink (Neovison vison) is a species that experienced unprecedented ecological success in the 20 th century, which can be seen in both the dynamic increase in its zoogeographical range, and in its effective adaptation to ecological niches in new areas. The driving forces of this phenomenon include intensification and globalization of mink farming, which is accompanied by introduction and rapid spread of the species outside its natural range. The first observations of mink in the wild in Poland took place in the middle of the last century. Within 60 years, American mink colonized almost entire country and the process of invasion and colonization is still ongoing. The high rate of invasion and ecological success achieved by the populations from the introduction is possible due to the high ecological plasticity of American mink, its high reproduc− tive potential, the availability of free ecological niche left by European mink (Mustela lutreola), extinct in many areas, and the frequent lack of natural enemies on the occupied territories. Dynamic geographical spread of allochthonous American mink is associated with a number of very serious ecological problems, primarily through predation, competition and aggression against indigenous fauna, as well as transmission of Aleutian mink disease virus. This results in fact that American mink is regarded as one of most dangerous invasive species in the world. In the absence of practical possibilities of its permanent eradication from Poland, local eradication programs on vulnerable areas (e.g. waterbirds breeding sites), as well as large−scale population size control, promotion of natural enemies and competitors, and improvement of living conditions of its prey− −species are most recommended. The most important in monitoring and control programs of alien populations is limitation of farm−animals escapes and recognition of methods for their simple and unambiguous identification. Indisputable determination of the free−ranging animals origin would allow for taking the appropriate actions against owners of the unsafe farms. At the same time, implementation of a holistic and systemic approach to solve the problem of the presence of American mink in the natural environment would help to fulfil Polish obligations resulting from ratified international conventions and EU law. KEY WORDS American mink, environmental risks minimization, feral population, invasive alien species Nature conservation and invasion of the American mink (Neovison vison) in Poland – a critical analysis ABSTRACT Ochrona przyrody a inwazja norki amerykańskiej (Neovison vison) w Polsce – krytyczna analiza problemu

Most often, genetic variation causing phenotypical changes is calculated exclusively upon the occurrence of non-synonymous variation. However, it has been increasingly more common to state that synonymous mutations and polymorphisms, as well as nucleotide variation present in introns, can have very serious biological effects. In the following work, the potential biological effect (including molecular phenotype) of nucleotide variation within the growth hormone gene in American mink (Neovison vison Schreb., 1777) was evaluated, based on multilocus genotypes of 389 individuals (wild mink from Canada, six colour types of ranch mink, mink acquired from the natural environment in Poland and Iceland), identified by direct sequencing. The focus is on the possible occurrence of changes in a splicing regulatory sequences and sequence motifs, different reading of codons and on an influence on the mRNA secondary structure. The results obtained confirm the hypothesis that synonymity of single-nucleotide variation does not always signify its neutrality.

A review of Dan Powell's 2010 book, Mink Trapping: A Deep and Complete Long Lining System. Chamberlain, SD: Register Lakota Printing. 174 pages.
Powell's effort to help trappers think strategically about their work would help all trappers to improve the efficiency and quality of their work. Too often, a trap-per's fur-fever causes him to neglect his family. Powell properly explains the importance of balance and how proper planning leads to high production in all aspects of one 's life.