130925-studie-wildlife-comeback-in-europe

Figure 1b.
Map highlighting
areas of range
expansion,
persistence and
contraction of the
Wolverine in Europe
between 1955 [31]
and 2009–12 [2, 18] .
Please note that the
contraction observed
from 1955 to 2012
is likely to be an
artefact of the
difference in map
resolution caused
by a disparity in
the accuracy of
the methods used.
Expansions in
southern Norway
are likely to be
overestimations
resulting from the use
of range information
comprising areas of
sporadic occurrence
in which the species
is culled.
Wolverine now occupies approximately 1,938,000
km 2 , which is just under 40% of its historical distribution
(Figure 1a).
The recent positive change in distribution is
also reflected in the abundance trend of monitored
Wolverine populations. The species shows a steady
increase of approximately 270% over the 26-year
period between 1979 and 2005, with a doubling in
number in the 1990s (Figure 2). The trend, which
starts in the late 1970s due to non-availability of
data before this point in time, is based on 19 populations
from Norway, Sweden, Finland and Russia,
representing a minimum of 245 individuals or 9%
of the total European population from 2009–12. It
should be noted, however, that this Figure is likely
to be an underestimate, as most of the populations
used density measures, which are unusable for
estimating the minimum number of individuals
represented. In addition, existing estimates may
not be reliable for this hard-to-monitor species.
because these bounties were paid per individual,
and den sites were often easier to find. Legal
protection, which started in Sweden in 1969 and
was gradually established in Norway between 1973
and 1983 [8, 29] , has therefore played a major role in
the recent comeback of the species. It has resulted
in increases in the populations of both countries [8] ,
and allowed the Wolverine to spread naturally into
the forested landscapes from which it had been
extirpated in Sweden [28] .
However, divergent management strategies
have led to differing rates of recovery in the two
countries. In Norway, the species is publicly hunted
using generous quotas, and there is extensive lethal
control in certain regional management zones [4] .
Some areas in the southwest follow a zero tolerance
rule regarding Wolverine breeding to minimise
conflict with sheep husbandry, which reduces the
probability of reproduction by 25 times compared
Figure 2.
Change in Wolverine
population
abundance by
decade and overall
change between
1979 and 2005.
Please note that
for this species,
95% confidence
limits could not be
calculated.
Drivers of recovery
300
The gradual range expansion and population
increase observed in Europe since the 1960s can
be explained by a number of reasons discussed
in the literature. Much of the initial contraction
observed in the Wolverine from the mid-19 th
century (Figure 1a) can be attributed to human
persecution due to livestock depredation [4, 8, 29] ,
which was reinforced by a bounty payment system.
The impact was primarily on females with cubs
% change
240
180
120
60
0
1960s 1970s 1980s 1990s 2000–05 1979–2005
123