130925-studie-wildlife-comeback-in-europe

The widespread range contraction is also
reflected in the population trend for European
populations of Iberian lynx (Figure 2). The trend,
which starts in 1965 due to non-availability of data
before this period, shows a decrease of around 85%
by 2005, with consistently negative change in all
decades except between 2000 and 2005 (Figure 2).
According to our data, species abundance
declined by 80% in the 1960s and 1970s, which is
in line with the 80% reduction estimated in Spain
for the period 1960–1978 [36] , with local extinctions
reaching a high in 1970–75 [7] . This decline
was previously attributed to the introduction
of myxomatosis from Australia via France [37] ,
however the most likely explanation is that this
factor made populations vulnerable to anthropogenic-induced
changes in land use, level of
exploitation, and prey and habitat availability [7] .
For example, urban migration after 1960 resulted
in the loss of diversity in the Mediterranean
scrubland at the landscape level, as well as the
replacement of native vegetation by plantations [7] .
A small but sustainable population of around
1,100 animals remained in the early 1980s [38] ,
although another rapid decline followed between
1980 and 1985 [7] . The introduction of Rabbit
Haemorrhagic Disease (RHD) in 1988 again caused
high mortality in rabbits [12] . While affecting the lynx
directly, profit losses from small game hunting due
to rabbit decreases may have encouraged owners
to optimise habitat for big game species, which
further suppressed rabbit recovery, and human-induced
mortality including illegal hunting and
traffic deaths will have also played a role [12] . Between
1950 and 1989, and an average of 31.5 lynx were lost
per year due to non-natural causes, although this is
likely to be an underestimation [39] .
Our results indicate that the 1980s were the
second most devastating during the study period,
with a decline of nearly 40% (Figure 2). Some
sources quote a decline of more than 80% between
1987 and 2007 [18] ; this could not be confirmed in
this study, where an increase occurred between
2000 and 2005. Protection, captive breeding
and other conservation measures are likely to
have contributed to this [38] . Overall, the decline
observed from 1960 is attributed to rabbit decline,
habitat loss and fragmentation, and non-natural
mortality [8, 39] . The abundance trend for Iberian
lynx is based on five populations from Spain,
representing an average 190 individuals or 68%
of the total European population from 2010. The
country coverage is 50% because the data set
comprises no populations from Portugal. However,
it is generally accepted that the species has gone
extinct in Portugal [9] , so it is reasonable to assume
that the coverage is, in fact, 100%.
% change
20
0
-20
-40
-60
-80
Drivers of recovery
1960s 1970s 1980s 1990s 2000–05 1965–2005
No associations with increasing or decreasing
population-level trends could be found in our data
set, which may be due to small sample size, as well
as the fact that a combination of different threat
processes may have affected the species at different
times over the past 50 years [8] . As discussed above,
the decline observed since the 1960s has been
attributed to a combination of prey base depletion
through disease, habitat loss and fragmentation,
and non-natural mortality [8, 39] . Fragmentation of
habitat and populations is a particular concern, as
Iberian lynx do not cross open areas over five km
wide [41] , making them very sensitive to discontinuous
ranges [23, 26, 42] .
While the recent increase in population size as
well as parts of the species’ range is insignificant
compared with the magnitude of former decline,
the identification of beneficial factors is relevant
to the future conservation of the Iberian lynx
(Table 3). Legal protection has been suggested as
one of the causes of the recent moderate recovery
in numbers, and although mortality ratios
were indeed lower after 1973, in some regions
the decrease of natural mortality started long
before, probably because of changes in game
management [39] . In addition, the high relative
density of lynx found in protected areas is likely
due to specific habitat management strategies as
opposed to protection per se [43] . While management
changes associated with a shift from small to large
game hunting was previously associated with
declines in Iberian lynx, lower levels of predator
control and the growth of thick scrubland may
have been beneficial for rabbits and, consequently,
for the lynx in the Sierra Morena [39] .
Management strategies have been intensified
within the framework of several EU LIFE
projects, which include a variety of conservation
measures such as habitat quality improvements,
monitoring, disease prevention and addressing
natural and human-caused mortality [10] . The
Figure 2.
Change in the Iberian
lynx population
abundance by
decade and overall
change between
1965 and 2005. Please
note that due to the
way change was
calculated, decadal
change does not sum
to overall change.
For this species,
95% confidence
limits could not be
calculated.
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