|Scientific Name:||Castor fiber|
|Species Authority:||Linnaeus, 1758|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Batbold, J., Batsaikhan, N., Shar, S., Amori, G., Hutterer, R., Kryštufek, B., Yigit, N., Mitsain, G. & Palomo, L.J.|
|Reviewer(s):||Amori, G. (Small Nonvolant Mammal Red List Authority) & Temple, H. (Global Mammal Assessment Team)|
The Eurasian beaver has shown good recovery across much of its range, as a result of conservation programmes. The highest numbers are found within Europe. Conservation measures are ongoing to prevent the population declining again and as long as these continue, there is no reason to continue to assess the species as threatened or Near Threatened. Now Least Concern. However, the Asian populations remain very small and under serious threat, and these populations urgently need conservation measures.
|Range Description:||The Eurasian beaver Castor fiber was once widespread in Europe and Asia. However, by the beginning of the 20th century, over-hunting had drastically reduced both the numbers and range of the species. In Europe, only a few isolated sites remained: parts of the Rhone (France) and Elbe (Germany), southern Norway, the Neman River and Dnepr Basin (Belarus) and Voronezh (Russia). A series of management measures and reintroductions have enabled the beaver to return to much of its former range, and there are now a number of rapidly expanding populations extending from Spain and France across central and eastern Europe to European Russia, and in Scandinavia and parts of western Finland.
Free-living populations of beavers are now established or establishing in most regions of their former European range, the main exceptions to date being Portugal, Italy, the south Balkans and Great Britain (Halley and Rosell 2002, Ceña et al. 2004). Detailed information on the status and distribution of the Eurasian beaver in each range state can be found in Halley and Rosell (2002), and information on the population that was translocated to Spain in 2003 can be found in Ceña et al. (2004). It is generally a lowland species, but occurs up to 850 m in Europe (Halley pers. comm. 2006).
In Mongolia, a small population exists along the Bulgan River in northern Dzungarian Govi Desert, in the south-western corner of Mongolia. Mongolian-German Biological Expeditions carried out conservation introductions along Hovd River in Mongol Altai Mountain Range in 1974, 1975, and 1978, and along Tes River in northern Hangai Mountain Range in 1985, 1988 and 2002. In all cases Mongolian beavers from the Bulgan River were used in order to protect the gene pool in the central Asiatic hydro-geographic basin (Stubbe and Dawaa, 1982; Stubbe et al., 2005a). A separate attempt to reintroduce beavers from Voronezh Reserve (Russian Federation) was unsuccessful (M. Stubbe pers. comm.).
Native:Belarus; China; France; Germany; Kazakhstan; Luxembourg; Mongolia; Norway; Russian Federation
Regionally extinct:Moldova; Portugal; Turkey; United Kingdom
Reintroduced:Austria; Belgium; Croatia; Czech Republic; Denmark; Estonia; Finland; Hungary; Italy; Latvia; Liechtenstein; Lithuania; Montenegro; Netherlands; Poland; Romania; Serbia (Serbia); Slovakia; Slovenia; Spain; Sweden; Switzerland; Ukraine
Present - origin uncertain:Bulgaria
|Range Map:||Click here to open the map viewer and explore range.|
By the beginning of the 20th century, the global population had been reduced to eight populations, totalling approximately 1,200 individuals (Halley and Rosell 2002). Protection (beginning with a hunting ban implemented in Norway in 1845), natural spread and reintroductions have resulted in a rapid recovery in numbers and range, particularly in Europe. In 1998, the global population was estimated at 430,000 (Nolet and Rosell 1998), by 2002 it had reached at least 593,000 (Halley and Rosell 2002), and in 2006 the minimum estimate was 639,000 (D. Halley pers. comm. 2006). This is almost certainly a considerable underestimate, as both population and range are in rapid expansion (Halley and Rosell 2002, 2003; D. Halley pers. comm. 2006). Considerable further expansion in range and population, especially in western Europe and the lower Danube basin, can be expected. If current trends continue, the Eurasian beaver will be a fairly common mammal in much of Europe within the next few decades.
However, populations in Asia are still considered small. In Mongolia, reintroductions have been successful and the population has reached 150, and in China the population is about 700 (Halley and Rosell 2002, EMA Workshop 2006, Smith and Xie in press).
In Mongolia in 1964, the population size was estimated to consist of 100-150 individuals (Stubbe and Chotolchu, 1968), rising to 200 individuals by 1973 (Zevegmid and Dawaa, 1973). In 1991, surveys estimated there to be approximately 300 individuals along Bulgan and Hovd rivers (Stubbe et al., 1991). The most recent population assessment was conducted in 2004, which recorded 40 lodges along Hovd River and estimated the population to consist of 130-150 individuals (Shar, 2005). Ten beaver settlements were recorded in the Tuvan section of Tes River in 2005 (A. Saveljev pers. comm.), and the Mongolian section of this river is believed to contain a similar beaver population (M. Stubbe pers. comm.).
The Chinese subspecies of the Eurasian Beaver (C. f. birulai) is one of the rarest and least known aquatic mammals in China. In the 1970s it was believed that only 100 animals remained in fewer than 20 family groups. Currently, only one substantial population is known, at the Buergan River Beaver Reserve along the Xinjiang-Mongolian border - a narrow strip 50 km long and only 500 m wide. Here the population is estimated to be only 500 animals, and only 700 may live in all of China.
|Habitat and Ecology:||Beavers are adapted for a semi-aquatic life, using a variety of freshwater systems, including rivers, streams, irrigation ditches, lakes, and swamps. They generally prefer freshwater habitats surrounded by woodland, but may occur in agricultural land or even suburban and urban areas (Tattersall 1999, Halley and Rosell 2002). In northern Scandinavia, beavers may be found right up to the limit of the willow zone in the mountains, where knee-high willow bushes are the only woody vegetation and it is iced over for 8 months of the year. This is not preferred habitat, but they can survive there. In many places, beavers live both on the valley floor, and on the mountain plateau above (where it is wooded), with a break in distribution where streams flow down the steep valley sides. In general beavers should be able to live in almost any freshwater habitat where there are trees or shrubs and the gradient is not precipitous. However, patterns of recolonisation demonstrate a clear preference for still or slow, laminar water flow if it is available (Nowak 1999, Halley and Rosell 2002, Halley pers. comm. 2006).|
The beaver's historic decline was caused by over-hunting for fur, meat and castoreum (a secretion from the scent glands), combined with loss of wetland habitats. Beaver populations were severely reduced in most countries by mediæval times, but the species clung on in marshes and other inaccessible places until the advent of efficient steel traps and accurate firearms in the 17th century; and then through to the 19th century there was a rash of final extinctions for these reasons combined with drainage of many of the large marshland areas in which the species clung on (all of the European refugia where the species survived, except in Norway, are extensive marshlands).
Today, beaver populations in Europe are expanding rapidly, and there are no major threats (e.g. threats of a magnitude likely to cause decline at the regional level). Competitive exclusion of the native European beaver C. fiber by its American cousin C. canadensis may be a threat in parts of Finland and north-west Russia, but it is not a major threat regionally. In Europe North American beavers are now confined entirely to Finland and north-west Russia, where populations are increasing only slowly (due to heavy harvesting). The former population at a reservoir near Paris has been removed, and populations introduced to Poland and Austria have apparently gone extinct in competition with C. fiber, the opposite of what has tended to happen in Finland and north-west Russia (it has been suggested that, due to differences in the life history of the two species, Eurasian beavers may have a competitive advantage at more southerly latitudes, whilst North American beavers may be more successful further north: D. Halley pers. comm. 2006). There are no serious prospects of further introductions (Halley and Rosell 2002, D. Halley pers. comm. 2006). The two species do not interbreed (Tattersall 1999). Road kill is an important source of mortality for some populations (Tattersall 1999). Rapidly expanding beaver populations may come into conflict with humans in some areas, as they do some damage to forestry and crops. Such damages should be put into perspective: they tend to be less severe than those caused by other species such as deer and voles, but are noticed because beavers are a new and unfamiliar species in areas where they have been recently introduced (Halley and Rosell 2002).
In Mongolia, illegal hunting for skins, meat and castoreum still occurs in some areas such as the Tes River. Habitat loss through selective clear-cutting of willow, upon which this species relies for food and shelter is also a threat; this is known to be occurring along the Bulgan River and is leading to isolation of small populations and inbreeding. Pollution of water systems is also a threat. A hydroelectric dam in the Chinese section of the Bulgan River prevents migrations in this area (M. Stubbe pers. comm.).
In China, firewood gathering has depleted much of the forest on which the beavers need to subsist; additionally heavy grazing pressure has further reduced vegetation needed by beavers.
A number of conservation measures have contributed to the species' recovery in Europe, including reintroductions and translocations, hunting restrictions, and habitat protection. It is listed under the Bern Convention (Appendix III) and the EU Habitats and Species Directive (Annex V for the Swedish and Finnish populations, Annex II and IV for all others). In Finland, C. canadensis populations are controlled to prevent them spreading into the west where C. fiber occurs. Halley and Rosell (2002) recommend regulated hunting as the optimal management regime in managed landscapes with healthy beaver populations. Management of beaver populations should be at the watershed scale, except where large human-made dams form significant barriers to spread. Early provision of interpretation and public viewing opportunities is also recommended, as this provides a benefit to the local economy through wildlife tourism, and helps foster positive attitudes to beavers (Halley and Rosell 2002). This has been a successful feature of several recent reintroductions. Reintroduction to Italy has been recommended in a European Union/Bern Convention Nature and Environment Series document (Nolet 1996). Considerable efforts have been made to develop a beaver reintroduction programme in Scotland, and a full public consultation showed strong support for such a scheme among the general public, including in rural areas where beavers were likely to be released (Halley and Rosell 2002).
In Mongolia, C. f. birulai is protected as Very Rare under part 7.1 of the Law of the Mongolian Animal Kingdom (2000), and is included as Rare in both the 1987 and 1997 Mongolian Red Books (Shagdarsuren et al., 1987; MNE, 1997). This subspecies is also listed as Very Rare under the 1995 Mongolian Hunting Law (MNE, 1996). Approximately 11% of the species’ range in Mongolia occurs within protected areas.
Conservation measures in place in Mongolia:
1) Bulgan Gol Nature Reserve was established along the Bulgan River in 1965 to conserve this species.
2) Many translocations and conservation introductions have taken place over the past 50 years to enhance the Mongolian population.
The species is considered Endangered (EN A1bcd) in the Chinese Red List.
|Citation:||Batbold, J., Batsaikhan, N., Shar, S., Amori, G., Hutterer, R., Kryštufek, B., Yigit, N., Mitsain, G. & Palomo, L.J. 2008. Castor fiber. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 05 March 2015.|