130925-studie-wildlife-comeback-in-europe

Reason for positive change
Species management
Legislation
Other
Land/water protection &
management
Figure 13.
Reasons for
resurgence for
the 18 mammal
species in this study.
Horizontal bar shows
the proportion of
species/populations
for which each reason
was identified.
Education
0 5 10 15 20
No. of species
Reasons for species recovery
Primary reason
Secondary reason
Tertiary reason
Overall, drivers of recovery reflect to a degree the
main threats that caused historical declines. As
such, legal protection (e.g. from overexploitation
and persecution, as well as site protection) and
targeted conservation action, were the overarching
reasons for species comeback. Here we provide a
more detailed overview of reasons for recovery for
mammals and birds separately.
Drivers of mammal species recovery
The data reveal that mammal species comeback
tends to rely on a variety of factors. However, for
16 of the 18 mammal species in the study, species
management (e.g. reintroductions, compensation
schemes, changes in hunting regimes) was
cited as one of the top three reasons for recovery,
followed by legal protection (13 out of 18 species;
Figure 13). Furthermore, both emerged as the most
frequently cited primary reason for an increase
in abundance over the study period, probably
because legal protection of species is likely to lead
to better species management in order to comply
with legislation.
Actively boosting existing or setting up new
populations, via translocations and reintroductions,
was the foremost type of species
management linked to increased abundances,
cited for 10 of the 18 mammal species as amongst
the top three reasons for comeback. Management
to reduce non-natural mortality, such as via
changes to hunting regimes and management to
decrease levels of persecution, was amongst the
top three reasons for comeback for five species,
including Harbour and Grey seals. Changes in
hunting practice may frequently be due to legal
protection as well, but we kept these categories
Box 1: How many should there be? Historic baselines for wildlife populations
For many thousands of years, humans have been present in
Europe and have made use of its living resources for food, clothing,
medicines and fuel. The status of European wildlife is therefore
part of a dynamic and changing system, and current trends in
European wildlife need to be interpreted against a sound understanding
of the magnitude and drivers of past changes.
There is a great need to appreciate historic sizes of wildlife
populations in order to gauge how wildlife populations in Europe
are changing today. This baseline level, against which current
and future wildlife populations can be measured, provides us
with the means to make accurate assessments of our successes,
or failures, in wildlife conservation.
The field of historical ecology, used in order to reconstruct
past changes, is developing rapidly. Only recently have scientists
started to unravel the long-term impacts of humans on
wildlife. For long-term trends in biodiversity, there often remains
little option but to set baselines to the point at which systematic
data collection was started, since long-term data sets are
frequently lacking [1] . This is highly undesirable, as systems have
often undergone dramatic change by the time monitoring
programmes start. Typically, for ecological data like estimates of
population abundance, good records began around the 1960s-
1970s. There are limited examples of longer-term abundance
datasets that precede this time period [1, 2] , though sometimes
inferences can be made using ancillary information (e.g. [3] ).
For occurrence or sighting data, there is a greater depth of
historical records from which inference on the changing state
of nature can be drawn. Resources such as museum specimens,
archaeological records and literature monographs can all
provide an enhanced historical record, though any inherent bias
must be carefully accounted for to gain an accurate picture of
the historical distribution of species [4] .
References
1. Willis, K.J., Arauo, M.B., Bennett, K.D., Figueroa-
Rangel, B., Froyd, C.A. & Myers, N. 2007. How
can a knowledge of the past help to conserve
the future? Biodiversity conservation and the
relevance of long-term ecological studies. Philosophical
Transactions of the Royal Society of
London B 362: 175–186.
2. Collen, B., Loh, J., Whitmee, S., McRae, L., AMin, R.
& Baillie, J.E.M. 2009. Monitoring change in vertebrate
abundance: the Living Planet Index. Conservation
Biology 23: 317–327.
3. Rosenberg, A.A., Bolster, W.J., Alexander, K.E.,
Leavenworth, W.B., Cooper, A.B. & McKenzie, M.G.
2005. The history of ocean resources: modeling
cod biomass using historical records. Frontiers in
Ecology and the Environment 3: 84–90.
4. Boakes, E.H., McGowan, P.K.J., Fuller, R.A., Changquing,
D., Clark, N.E., O’Connor, K. & Mace, G.M.
2010. Distorted views of biodiversity: spatial and
temporal bias in species occurrence data. PLoS
Biology 8: e1000385.
276