Highlight Published
30 Jan 2014 - Bat numbers increased more
than 40 % between 1993 and 2011, after declining
for many years, according to a new report
by the European Environment Agency (EEA),
which considers the state of bat populations
in a handful of countries across Europe.
It is extremely encouraging
to see bat populations increasing after
massive historic declines. It suggests that
targeted conservation policies over the
last years have been successful. But many
bat species are still endangered, so preserving
their habitats is still an important priority.
Hans Bruyninckx, EEA
Executive Director
The EEA report on bats
is the most comprehensive study yet made
of European bat population trends, studying
16 of the 45 bat species found across the
continent. The study is the first to compile
data from ten existing monitoring schemes
in nine countries, building a prototype
European-scale indicator of bat population
trends. Surveyors counted and catalogued
bats hibernating at 6 000 sites in nine
different countries. Overall these species
appear to have increased by 43 % at hibernation
sites between 1993 and 2011, with a relatively
stable trend since 2003.
“It is extremely encouraging
to see bat populations increasing after
massive historic declines,” EEA Executive
Director Hans Bruyninckx said. “It suggests
that targeted conservation policies over
the last years have been successful. But
many bat species are still endangered, so
preserving their habitats is still an important
priority. Monitoring bats also helps understand
changes in wider ecosystems, including climate
change, as they are highly sensitive to
environmental change.”
European bat populations
had previously declined significantly, particularly
during the second half of the 20th century,
largely due to intensifying agriculture,
changes in land use, intentional killing
and destruction of roosts. Bat numbers have
also fallen as their habitats have shrunk,
fragmented and degraded. Additionally, they
have been poisoned by timber-treatment toxic
chemicals such as dieldrin, used in roofs.
Bats tend to be long-lived
animals with a slow rate of reproduction,
so environmental or human pressures can
cause populations to decline very rapidly,
and they tend to recover slowly. For these
reasons bats should still be considered
vulnerable, the report notes. While signs
of increase are positive, conservationists
consider that current populations are still
likely to be smaller than they were before
they declined.
The report brings together
for the first time data from, Latvia, Hungary,
the Netherlands, Austria, Portugal, Slovenia,
Slovakia, the United Kingdom and the German
states Bavaria and Thuringia. The prototype
indicator should be interpreted cautiously
at this stage, as many species and countries
are yet to be represented. It is hoped that
this report will lay the groundwork for
an even more comprehensive study in coming
years, as bats are widely monitored across
Europe.
Most of the species
studied seem to be increasing or stable
in number. Eight bat species increased moderately,
including Daubenton's bat (Myotis daubentonii).
The Whiskered bat and Brandt’s bat (Myotis
mystacinus / brandtii) are so difficult
to tell apart that they are counted together.
These were the only species to register
a strong increase in numbers between 1993
and 2011, according to the survey. Three
were stable, two species were uncertain
and only the Grey long-eared bat (Plecotus
austriacus) declined, albeit moderately.
Nonetheless, many of these species are still
rare and vulnerable.
The report states that
the apparent population increase of most
species may reflect the impact of national
and European conservation legislation, species
and site protection, targeted conservation
measures and widespread awareness-raising,
particularly under the EUROBATS agreement.
Europe’s wildlife is
under pressure in many parts of Europe -
only 17 % of habitats and 17 % of more than
1 000 animal and plant species assessed
under the Habitats Directive (Art.17) have
favourable conservation status.
The Bat Conservation
Trust (BCT), the Dutch Mammal Society (DMS)
and Statistics Netherlands (SN) were key
members of the project team behind the EEA
report. Other organisations that contributed
data and helped to develop the indicator
included national bat and nature conservation
NGOs, governmental organisations and individuals.
In addition, thousands of volunteer surveyors
helped collect the data used.
The EEA report on bats
uses a similar methodology to a recent report
detailing the dramatic decline of grassland
butterflies in Europe. Numbers of these
insects almost halved between 11000 and
2011 due to intensifying agriculture and
a failure to properly manage grassland ecosystems,
the report found.
Note: These images can
be used by press organisations free of charge,
as long as they are credited in the same
way as above. Anyone else seeking to use
these images please contact Sian Moore at
the Bat Conservation Trust.
Plecotus austriacus Image © Hugh Clark/Bat
Conservation Trust
