European Mink (Mustela lutreola) Status, threats and actions needed August 2013

Transcription

1 European Mink (Mustela lutreola) Status, threats and actions needed August 2013 By Tiit Maran: Director of Foundation Lutreola Scientific Secretary of Tallinn Zoo and Head of Species Conservation Research Lab Associate Professor of Zoology in Tallinn University Member of the following IUCN SSC Specialist Groups: Small Carnivores, Conservation Breeding and Invasive Species The paper is divided into two parts: introductory information and the list of suggested actions for European Mink conservation both on European and national scale. For those familiar with the issues related to the European Mink conservation, it is recommended to skip the first part and focus only on the second one. CONTENTS Introductory information... 2 Original range... 2 Agents of decline... 2 Current status... 2 Actions underway... 4 All European actions needed... 5 Actions needed in Member States... 7 Spain... 7 France... 7 Romania... 7 Estonia

2 INTRODUCTORY INFORMATION Original range The European Mink was formerly a widely spread species in Europe. It ranged from mid-finland to the Black sea. In the east, it reached to the Ural Mountains with even some evidence of limited distribution to the eastern side of the mountain range. In western Europe, the historical extent of its range is not fully known. It is not clear how far to the west the initial range expanded. The first records from France and Spain date back to the mid-19 th and mid-20 th century, respectively. This gives ground to the suggestion that this species is a relatively recent arrival there. Also, the exceptionally high genetic uniformity of the western population seems to support the idea of recent (secondary?) expansion of the species into France and Spain. Agents of decline Several agents are driving the decline of the European Mink. The most of important of these are habitat loss, over-exploitation and the impact of the introduced American Mink (Neovison vison). The relative roles of these factors have varied through time and they usually have acted in concert, with cumulative effect. In addition, also other minor factors may pose local threats to the remnant populations like hybridization, road casualties, Aleutian disease, secondary poisoning etc. The American Mink is nowadays by far the most threatening agent due to the difficulty to eliminate its impact. However, in such a Critically Endangered status as the European Mink now finds itself, any minor additional factor may result in full extinction of a remaining local population. Current status According to the last assessment of The IUCN Red List of Threatened Species, published at the end of 2011, the European Mink is regarded as a Critically Endangered species (the highest category of extinction risk). This critical global status of the species was already suspected during the previous assessment in 2006, but due to lack of evidence about its status in Russia, it was classified only as Endangered (the rank below Critically Endangered). Even then, Critically Endangered status was clearly warranted for the populations in the European Union. The current natural range consists of few isolated fragments: in northern Spain and western France, in the Danube delta in Romania, in the Ukraine and Russia. The species is in decline in its currently remaining range enclaves. The European Mink seems still to be widespread in the Danube delta in Romania. However, American Mink farming in the Ukrainian side of the delta poses a serious threat to the species. In the Vologda Region (Russia), considering the rapid decline of the species in the neighbouring regions and the presence of the American Mink, it is not likely that the European Mink populations will hold out much longer. In the Arkhangelsk Region (Russia), a 2

3 population exists in the northwest of the region close to the northern limit of the species s range. This results in very low abundance of the species there. The presence of the American Mink is likely to pose a serious threat to the European Mink s long-term existence also there. Some national estimates of population size: a. Spain: around 500 mink spread over approximately 2,000 km of rivers. The population management is divided between 8 local provinces with relatively low-level coordination of actions. So far the population has survived largely because of regular American Mink control on border of, and within, the European Mink range during last 10 years. The results of the control, however, are jeopardized by 3 (2 in Basque Country and 1 in Castilla y León) American Mink farms inside the range (because escapees from farms are serious threat to the wild European Mink population) as well as expansion of existing populations of feral American Mink. Any decrease or cessation (even a temporary one) in American Mink control will inevitably result in the fast collapse of the European Mink population in this country. Right now such a decrease is possible, given the paucity of funding, in the current economic climate. Further, the prohibition of mink-farming in some European Union countries has resulted in increased strong pressures to establish new mink farms in countries which have not yet prohibited them, notably Spain, even inside European Mink range. b. France: the last assessment is around 10 years old. The present status is unknown. It is suspected that the overall number of European Mink individuals remains below 200 and these are scattered between separated habitat patches. In May 2013, the construction of a European Mink conservation breeding facility was launched in the zoological gardens Zoodysee for around 60 animals. However, until the present range and the status of the wild European Mink and its habitats remain unclear, one can hardly come up with any promising reintroduction or enforcement strategy of the species. c. Danube delta, Romania: the number and distribution of the species are not fully clear. The only recent source of information is the European Mink handbook, published in The decline is obvious from hunting bag statistics: in 1956, 3800 pelts and in 1980, 80 pelts. There are various statements of the population size from mink to mink. No reliable estimate of the size is available, because so far the inventories undertaken have not followed sampling design allowing generalizations for the whole area. Ad hoc observations suggest some recent (since 2010) increase in number, although again the lack of structured sampling design in surveys prevents any well-grounded conclusions about trends. An American Mink published record in 2003 in the Danube delta suggests potential invasion of the American Mink into the delta. This is especially alarming because, if this occurs, a rapid decline in the European Mink population is inevitable. d. Belarus: the species is considered to be extinct in both last two small range fragments. e. Ukraine: the European Mink was recently re-discovered in the Danube and Dniester deltas. A proposed population figure (reliability unknown) for the whole country is around 500 and the population is considered to be highly fragmented. The American Mink is present. The 3

4 population, if it still exists, is quite likely to be at the very edge of extinction. f. Russia: in most of the country s 61 administrative regions within the species s historical range it is extinct or believed to be extinct (40 regions, 66%). Only in seven regions is it known to be extant. In nine further regions it is believed to survive still. In only 12 regions is the European Mink expected to survive for longer than 10 more years. The American Mink is now present almost within the whole remaining range. g. Estonia: the last record of a native wild individual dates back to Since 2000 a release programme in Hiiumaa Island is going on, supported by conservation breeding program in Tallinn Zoo. The island population is still not sustainable. h. Germany: the wild population disappeared at the end of 19th century. The two release operations have not resulted in wild populations so far. Actions underway General: conservation breeding programme in the frame of European Mink EEP (European Endangered Species Programme) with about 250 mink in around 15 facilities (majority in Tallinn Zoo) since Spain: (a) conservation breeding programme since 2004, (b) pilot reinforcement in the province of Alava , (c) ongoing special programme to control American Mink within and around European Mink range, (d) monitoring of European Mink covering most of the autonomous communities, (e) habitat restoration operations, (f) various conservation research. France: in 2010 a government programme for conservation breeding and reintroduction was started for the next six years. In May 2013, the construction of the facility was launched in zoo Zoodyssee (in Chize). Germany: (a) conservation breeding programme in Osnabrück managed by Association Euronerz under surveillance of the European Mink EEP programme, (b) two reintroduction programmes: in Saarland since 2006 and in Lower Saxony since in Results are unclear till now. Estonia: (a) conservation breeding in Tallinn Zoo (around 100 mink) since the late 1980s and coordination of European Mink EEP programme, (b) establishment of island population in Island Hiiumaa (Dagö) since 2000, (c) various conservation research studies, (d) regular monitoring of establishing island population in Hiiumaa Island, (e) habitat restoration in preparation in Hiiumaa Island, (f) plan prepared to test the community conservation approach in mainland Estonia for control of the American Mink and release of European Mink. Romania: (a) continuous live-tapping for European Mink monitoring since 2003, (b) collection of direct and indirect sighting/observations of European Mink by several field technicians, (c) the handbook for Mink conservation published in (d) ecological restoration of agricultural polders and fishponds since 1994 (over 15,000 ha restored) is beneficial for mink, (f) 4

5 limited funding hampers the plans to perform inventory of European Mink presence outside Danube Delta Biosphere reserve. The Ukraine: no information about any conservation action. Russia: no information about any conservation action. ALL EUROPEAN ACTION NEEDED All-European coordinated action is urgently needed because, as indicated below, piecemeal approaches are not succeeding in stopping this species s decline. The required actions can be divided into umbrella-actions and several problem- or goal-oriented action groups: 1. All-European action plan for the European Mink. Currently, various actions are underway in several Member States without coordination and/or information dissemination between Member States, even though these actions would benefit from such exchanges. The European Mink is regarded as a priority species and species of European Community importance. The EU Habitats Directive obliges Member States to take actions to ensure the favourable status of the species. Reaching the favourable status of the species is unlikely with isolated actions by Member States. It is most likely that without dramatic change in the management of this species, it will disappear from the European Union fauna by The formulation of goals, required actions and mechanisms for activity coordination between Member States are urgently needed. The elaboration of a European Mink action plan would be the simplest way to achieve this. 2. Awareness campaign. Despite the European Mink s critical status, the problem of the European Mink s demise and the need for focussed conservation efforts has not been reflected much in the mass media. Therefore, public awareness about European Mink conservation issues and needs is pretty low. This is particularly obvious if a comparison is made with the mass-media coverage that the Iberian Lynx, Lynx pardinus, has received. Public support for European Mink conservation actions is of the utmost importance, and to ensure this it is necessary to prepare and conduct professional awareness and marketing campaigns about the species. 3. Ex situ management of the species. Given the critical status of all the wild populations, the effective management of captive population is critical to secure the maintenance of the species genetic diversity ex situ and, in this way, to keep the option for species recovery in the wild open for the future. Proper genetic management of the population needs a captive population larger than is financially feasible for any single Member State. Therefore a joint 5

6 all-european management of the captive population is essential. This requires swift and good coordination and exchange of information. 4. Mitigation of the impact of American Mink. Three basic actions could mitigate this impact: (a) Streamlining mink-farming legislation in EU countries. Current efforts to regulate American Mink farming in several mink-farming countries in European Union have resulted in mass-opening of American Mink farms in other EU countries, so far without such rules. One example is Spain, which as a European Mink range-state is likely to result in catastrophic additional negative effect on the country s remaining European Mink populations. There is urgent need to streamline mink-farming legislation in EU countries, for instance by means of minimum biodiversity safety standards applicable to mink farms in all Member States. (b) Reduction of American Mink escapes from fur-farms. Because the origin of American Minks in the wild cannot be traced back to the source farm, the problem of unintentional escapes has been impossible to control. Yet, farms are the source of the spread of many feral American Mink nowadays, as shown by some relatively recent research articles from Poland, Denmark and Russia. If the source cannot be traced back, the polluter cannot be sanctioned for the pollution (escaped American Minks). A new forensic technique of genetic identity cards (GICs) for animals is currently being elaborated. If the farms are obliged to make GICs for their breeding stock in certified laboratories and this information is available to authorities, the source of feral American Minks can be easily traced back to the farms and the farms can be sanctioned for polluting the nature with alien species, forcing them, in this way, to reduce the level of escapes. (c) Promotion of American Mink control techniques. Spain has long experience in reducing the number of American Minks in the wild with techniques of live-trapping. This is one reason why this country hosts such a significant remaining population of this species. Also, Estonia effectively removed the American Mink from Island Hiiumaa. Similarly, UK and Finland have conducted American Mink control programmes on islands. The generalised and synthesised experience from these efforts can be a key for implementing similar actions in other potential European Mink rescue regions, e.g. in France and in Romania. 5. Promoting (re-)introduction efforts. Estonia and Spain, and also Germany, have gained a lot of experience with (re)-introductions of the European Mink. The gained experience can be used to launch similar actions in other Member States without performing local trial-error learning process in each country. Collaboration and all-european approach to the reintroduction operations can help to identify suitable sites for reintroduction and to apply the best-known techniques for establishment of new wild populations. 6

7 6. Improvement/restoration of riparian habitats. The remaining as well as the newly established populations are, as a rule, very restricted in the area used. Because of this they are very sensitive to environmental variations. Therefore, actions of habitat restoration, which could result in the increase of the population size, should be regarded as of high importance. The European Mink is fully dependent upon the quality and availability of the riparian habitats. The latter, along with all other freshwater habitats, are highly endangered in Europe and therefore the European Mink can be regarded as perfect flagship species for riparian biodiversity. ACTIONS NEEDED IN EU MEMBER STATES Spain 1. Centrally coordinate American Mink eradication/control and European Mink status monitoring. 2. Ensure continuous funding for American Mink control and monitoring. 3. Remove the existing 3 American Mink farms within European Mink distribution area. 4. Extend the reintroduction/reinforcement programme. France 1. Assess the present status of the species in the country. 2. Elaborate the aims and procedures for the conservation breeding programme. 3. Identify sites for release of the European Mink. 4. Determine release technique for reintroduction. 5. Identify management tools to avoid invasion of the American Mink into European Mink release areas. Romania 1. Determine sampling methodology for status inventory; undertake the inventory itself. 2. Determine sampling methodology for monitoring scheme to reveal the trends in the status of the population; undertake the monitoring scheme itself. 3. Identify potential threats with emphasis on American Mink invasion routes. 4. Radio-track animals to study home-range, habitat use and movements of the European Mink in Danube Delta. This action is important because in the delta the Minks are likely to have typical linear home ranges along watercourses, but instead have two-dimensional ranges. 7

8 This prevents the use of the results of studies done elsewhere (investigating animals with linear home-ranges) in designing management in the Danube Delta. 5. Undertake a public awareness campaign with the preparation of species identification materials. 6. Study the potential of captive breeding management in Romania, as a sub-programme of the whole European programme. Estonia 1. Restore key habitats in Hiiumaa Island. 2. Continue and expand the captive breeding programme. 3. Test the potential for starting restoration of European Mink populations in mainland with community conservation approaches. 8