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Threats to the European mink

The main threats to the European mink are as follows:

1.   Invasion by the American mink: in Spain, this is the key threat.

The American mink is a larger, more aggressive species, which competes for food and space, and reproduces more successfully. This is leading to the disappearance of the European mink in those areas in which both species co-exist.

At first sight, both mink species are virtually identical, the only discernible difference being the muzzle: the European mink has a white upper and lower lip, whilst the American mink only has a white lower lip…

Although, for the time being, the presence of the American mink has not been detected in the rivers in Navarre, each year the Ministry of the Environment conducts captures in rivers in the neighbouring autonomous communities in order to control this invasive species.

2.    The destruction and degradation of its habitat is another factor contributing to the regression of the species. 

The flood plains have been occupied by agricultural crops and poplar plantations, invading the areas which should be reserved for the development of natural copses and wetlands, necessary to maintain a high level of biodiversity.

The Navarre Government has been working towards increasing the potential habitat of the minks, thereby reducing its risk of extinction. The projects implemented in this respect are focussed on the following actions:

  • The elimination of structures preventing river movement and, therefore, the rejuvenation of the copses and the natural formation of habitats.
  • The creation of favourable breeding areas.
  • The restoration of river bank vegetation to facilitate mink movement and shelter.
  • The publication of a technical document that sets out the guidelines to follow in order to minimise the negative impact of human activity on the species.

3. Death from being struck by a vehicle.

This is another cause of death, seen in the roads crossing the area coming within the European Natura Network, corresponding to the scope of this project.

During 2007, a total of eight black spots were improved and it was subsequently seen that all were used by the European mink and other carnivorous animals.

Currently the Government of Navarre is including fauna crossings that are adequate for this species, in new roads.

4. Drowning inside irrigation siphons. 

Irrigation siphons are used by minks and other carnivorous species for feeding. They jump inside for food, where they are then trapped and unable to get out, leading to death by drowning.

When upgrading irrigation systems, where minks are known to be present, siphons with ramps are constructed in order to allow the animals to get out.

5. Canine distemper virus.

Another great threat to the mink in Navarre is the disease produced by the canine distemper virus, which also affects other wild and domestic carnivorous species. This disease spreads rapidly in high density animal populations, such as the case of the population of European minks living in the lower reaches of the Arga and Aragón rivers.

Studies have been conducted since 2005, demonstrating a considerable drop in this population in addition to an increase in the number of mink specimens that are seropositive to the virus.

6. The great genetic resemblance between the minks at the Site.

Given the fact that this is a dense and isolated population, all specimens are genetically very similar (they could be said to be first cousins), which means that minks have fewer possibilities of adapting to environmental changes, lower defences in the face of diseases and, therefore, a greater risk of extinction.

If one family member falls ill, it is very likely that the rest catch the disease and all the family and neighbours die.

For this reason, there is an ongoing effort to monitor the health status of the population and to precisely determine the consequences and possible solutions to this low genetic diversity.

Partners


    Gestión Ambiental de Navarra, S.A. Fundación Crana Tragsa

Co-financers


    Gobierno de Navarra Gobierno de España

LIFE+ Environmental Recovery of the River Territory: a vital area for the European Mink (Mustela lutreola) | LIFE+ MINK TERRITORY