130925-studie-wildlife-comeback-in-europe

Table 3.
Major reasons for
change in the status
of the Eurasian
beaver in Europe.
a nearby German wildlife park and removal is
planned [2] .
Rank Reason for change Description
1 Legislation – Legal
protection and hunting
restrictions
2 Species management
–Reintroductions and
translocations
3 Other – Natural
recolonisation
4 Land/water protection and
management –Habitat
restoration and protection
However, any increase in distribution or
Following effective legal protection in 1899, the
beaver increased in Norway from 60–120 animals
to 1,000 by 1910 and 7,000 in 1919 [5] .
All remnant populations received legal protection
at the beginning of the 20th century [5] .
Population growth resumed in Belarus after a
hunting prohibition in 1996 [5] .
Initially, reintroductions were motivated by the fur
trade, consisted of hard releases and lacked habitat
suitability assessment, but latterly the focus
was more on conservation and more thorough
research [5] .
Reintroductions and translocations have saved
remnant populations from extinction and have
been key in the recolonisation of areas from
which the beaver had gone extinct. Altogether,
reintroductions and translocations have taken place
in at least 25 European countries [5] .
Viable populations have been established in all
countries where reintroductions have taken place [5] .
Eastern Norway was repopulated by individuals
from the adjacent Swedish population [5] .
The Estonian islands of Saaremaa and Hiiumaa were
colonised by natural spread in the 1990s [5] .
The population in Slovenia derived from releases in
Croatian watersheds [2] .
Beaver select the very best habitat available [5] , but
will progressively relax their criteria as better sites
are occupied [2] .
Poor habitat believed to be limiting reproductive
success in Biesbosch National Park in the
Netherlands [5] .
The conservation and regeneration of riparian
zones around rivers for flood control has created
suitable beaver habitat around Europe [5] .
number also entails greater potential for conflict
with humans. While public opinion towards the
beaver and its reintroduction is often positive [23] ,
those that are more directly affected by beaver
behaviour such as farmers and foresters, may
display greater scepticism, although some are
enthusiastic about the possibility of beaver
presence [2] . Level of acceptance depends primarily
on social factors [2] , and these need to be addressed
to mitigate problems. However, there are also
opportunities for the local economy through
wildlife tourism, so early provision of interpretation
and public viewing opportunities are
recommended, and this will also help foster
positive attitudes towards beavers [5] .
There is a particularly great opportunity to
promote the positive ecological effects of beaver
engineering, including the increase in biodiversity
resulting from beaver-induced changes in
habitat, and this has been the focus of more recent
research. Through the creation of ponds, the beaver
increases the amount of available nutrients, which
leads to algae and plant growth. As a result, invertebrate
species richness and biomass are higher
in beaver-influenced streams [24] and clearings [25] .
In Bavaria, 38 species of dragonfly were recorded
at beaver sites, with 11 profiting directly from the
presence of the species [26] . However, vertebrate
species also benefit: twice as many fish species
occur in beaver-influenced habitat, with densities
of up to 80 times higher than in non-beaver sites [26] .
Greater numbers of amphibian species were
present in beaver sites in the Eifel [27] and Bavaria,
where half of all 12 species benefited directly from
beaver activity [26] . In a Russian study, amphibian
productivity was higher in beaver compared
to non-beaver sites [28] . This increase in fish and
amphibian prey results in greater bird variety at
beaver sites, with over 50 rare species (e.g. Black
stork Ciconia nigra) recorded in Bavaria [26] . There is
also evidence that other mammals such as otters,
which can use beaver lodges, take advantage of
the increase in available food [26] . More recently,
studies have demonstrated a positive effect of
beaver clearings for insectivorous bats, providing
new foraging sites for species such as Pipistrellus
spp [29] . More generally, the beaver can support the
necessary restoration of waterways undertaken in
response to climate change and mitigate effects
such as increased flooding at extremely low
cost [26] .
After a long absence from a large proportion
of its range, the Eurasian beaver is now slowly
reclaiming its role as an ecological engineer
and keystone species in European freshwater
ecosystems. The species will undoubtedly increase
further in number and range over the coming
decades, and as confinement to a particular stretch
in a watershed is impractical in the absence of
strong artificial barriers because of the species’
readiness to disperse, management will have to
be implemented at the watershed scale [11] . The
associated benefits of waterway restoration and
potential for tourism will likely outweigh the
cost of beaver-related damage; however, potential
conflict will have to be managed in some countries
to allow for peaceful coexistence and mutual
beneficence of beaver and man.
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