Ray Collier Country Diary- Mink
Mink - 1st December 2008
Escapes of non-native mammals into the wild have caused serious problems in the Highlands such as the damage to agriculture by the rabbit and sika deer, either introduced for sport such as in Strathdearn south of Inverness or escapes from deer parks such as Rosehall in Sutherland that brought their own problems. Sika are now freely hybridising with red deer to the extent that some people believe there will eventually be no pure red deer anywhere in mainland Scotland. Perhaps the most calamitous of all the introductions has been the North American mink that was originally imported to Britain in the late 1920s with the aim of breeding them in captivity for their valuable pelts. The first mink farms in Scotland were established in 1938 but everyone underestimated the ability of the mink to escape and they soon became established in the wild.
Mink are about the size of a pine marten but slightly smaller with the original wild ones being dark chocolate brown which looks black especially when wet. There is often a white chin patch and the white varies in shape and size so no individual is the same. The mink in captivity were bred to a variety of shades and colours, but once breeding in the feral state the offspring soon revert to the original colour and pattern. The normal litter is five to six and the young are weaned after eight weeks, reach adult size in four months, and can breed the following year. The breeding sites, called dens, have been found in a variety of places such as in tree trunks, and holes and crevices among stones including scree.
Soon after the mink were brought into the "fur-farms" there were reports of escapes and of feral mink living in the wild, but it was not until 1956 that the first breeding was noted. At first the animals were regarded as pests and they were trapped and shot wherever possible, and although thousands were killed it had little effect on the populations. At one time there was even a school of thought that said we might as well accept the mink as an addition to our wildlife as it seemed to be permanently established and in any case eradification did not seem a possibility. As the mink numbers rose and it spread through much of the landscape from hills to coastline and woodland to moorland their effect became more apparent. Part of its success is the very wide range of food they will predate. Rabbits, where common, are a major food but myxymatosis still effects the numbers of rabbits and other food is sought . Mink on the coast can cause havoc in seabird colonies and any ground nesting birds. Breeding birds on islands are often predated such as gulls and terns and some of these colonies were wiped out. Coastal mink will feed on prey found in rock pools such as crab and blenny whilst in rivers they take all species of fish but especially the slow moving ones such as eels. There is evidence that they have had a devastating affect on water voles and on some rivers and burns these increasingly rare mammals have been wiped out. At one time it was thought that mink displaced otters but now the reverse seems the case so there must have been other factors involved. It now seems that where otters moved into rivers and burns the mink move out. Better techniques for capturing mink have now evolved so there is the chance that the numbers of mink can at last be controlled.
Escapes of non-native mammals into the wild have caused serious problems in the Highlands such as the damage to agriculture by the rabbit and sika deer, either introduced for sport such as in Strathdearn south of Inverness or escapes from deer parks such as Rosehall in Sutherland that brought their own problems. Sika are now freely hybridising with red deer to the extent that some people believe there will eventually be no pure red deer anywhere in mainland Scotland. Perhaps the most calamitous of all the introductions has been the North American mink that was originally imported to Britain in the late 1920s with the aim of breeding them in captivity for their valuable pelts. The first mink farms in Scotland were established in 1938 but everyone underestimated the ability of the mink to escape and they soon became established in the wild.
Mink are about the size of a pine marten but slightly smaller with the original wild ones being dark chocolate brown which looks black especially when wet. There is often a white chin patch and the white varies in shape and size so no individual is the same. The mink in captivity were bred to a variety of shades and colours, but once breeding in the feral state the offspring soon revert to the original colour and pattern. The normal litter is five to six and the young are weaned after eight weeks, reach adult size in four months, and can breed the following year. The breeding sites, called dens, have been found in a variety of places such as in tree trunks, and holes and crevices among stones including scree.
Soon after the mink were brought into the "fur-farms" there were reports of escapes and of feral mink living in the wild, but it was not until 1956 that the first breeding was noted. At first the animals were regarded as pests and they were trapped and shot wherever possible, and although thousands were killed it had little effect on the populations. At one time there was even a school of thought that said we might as well accept the mink as an addition to our wildlife as it seemed to be permanently established and in any case eradification did not seem a possibility. As the mink numbers rose and it spread through much of the landscape from hills to coastline and woodland to moorland their effect became more apparent. Part of its success is the very wide range of food they will predate. Rabbits, where common, are a major food but myxymatosis still effects the numbers of rabbits and other food is sought . Mink on the coast can cause havoc in seabird colonies and any ground nesting birds. Breeding birds on islands are often predated such as gulls and terns and some of these colonies were wiped out. Coastal mink will feed on prey found in rock pools such as crab and blenny whilst in rivers they take all species of fish but especially the slow moving ones such as eels. There is evidence that they have had a devastating affect on water voles and on some rivers and burns these increasingly rare mammals have been wiped out. At one time it was thought that mink displaced otters but now the reverse seems the case so there must have been other factors involved. It now seems that where otters moved into rivers and burns the mink move out. Better techniques for capturing mink have now evolved so there is the chance that the numbers of mink can at last be controlled.
posted by Corinne @ 11:55 AM
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