British Bats Face Challenges After Second Cold Spring In A Row

Latest figures from the National Bat Monitoring Programme show there were fewer British bats counted last year than the year before. With insect numbers down this summer and with bat breeding season delayed by the unseasonable start to this year conservationists are concerned.

Dr Kate Barlow, Head of Monitoring at the Bat Conservation Trust says,

"After 2 years of long, wet, winters and a particularly late and cold start to summer this year, the outlook isn't too promising for our bats. The most recent results from the National Bat Monitoring Programme showed that there were fewer bats were counted in 2012 than in 2011 for most species monitored.

And, after the coldest march in fifty years, summer this year has a late start and things are still running behind schedule for some species. This year Britain's bats need all the help they get."

"A National Trust report last month has revealed that this year, winged insect numbers are also down. So bats, struggling to bounce back from last year, this year's cold spring and delayed summer, may face food shortages, particularly those species that rely on moths."

"Bats are long-lived for small mammals, some species routinely live up to 20 years. All our bats produce only one baby a year (twins are very rare) so a few years of bad weather could have dramatic impact on numbers of bats if they are unable to find enough food to allow them to breed successfully. "

Several of Britain's bat species are listed as European Priority species, highlighted as among the most at risk species in Europe with numbers having declined steeply over the last century, thanks to a variety of reasons including changes in farming and land use, the use of pesticides and in some cases persecution.

Protection under law offers a lifeline but we need more volunteers

The fact that bats and their roost sites are protected at law provides a lifeline to those colonies of bats who have managed to survive the inclement weather.

At this time of year babies are usually being born in maternity roosts, summer gatherings of female bats giving birth and suckling their young. Mothers usually leave their young in crèches in the roost whilst they go out to feed at night. Protecting these roosts secure the future for these threatened creatures, many of which are found living alongside us in buildings.

Some positive news

Over the past 15 years, the National Bat Monitoring Programme has shown that population trends are increasing or stable for all of the 10 species (or groups of species) that we survey. Whilst these are positive results, it should be remembered that the trends reflect relatively recent changes to bat populations and before this time, in the second half of the twentieth century, there were considerable historical declines in bat populations. The overall positive trends over the last 15 years are not affected by the recent low reported bat numbers, but we need to keep a close eye on what is happening following the recent spell of bad weather for bats.

To help count bats this summer for the National Bat Monitoring Programme visit www.bats.org.uk/nbmp

If you find a bat out during the daytime or grounded or injured at any time, please call the Bat Helpline on 0845 1300 228.

Detail on figures

The most recent results from the National Bat Monitoring Programme showed that there were fewer bats were counted in 2012 than in 2011 for most species monitored.

In 2012 our volunteers counted bats at 704 summer roosts of seven different species. Overall, numbers were down at roosts of six of these seven species.

Activity levels of four bat species are also monitored by our volunteers through a summer bat detector survey. This survey was carried out at 243 sites across the UK in 2012. Overall activity levels of all species were lower than 2011 levels.

The very poor (cool and wet) summer of 2012 may have had an effect on the foraging and reproductive success of some out our bat species.

The activity levels of all four species monitored through the Field Survey (common pipistrelle, soprano pipistrelle, serotine and noctule) were all lower than in 2012 compared to 2011, although in most cases this drop has not affected the overall population trends for the period of monitoring.

Roost Counts were also down on 2011 numbers for most species monitored (lesser horseshoe bat, Natterer's bat, common pipistrelle, soprano pipistrelle, serotine and brown long-eared bat). Only the greater horseshoe bat didn't suffer losses.

For further information please contact Heather McFarlane at the Bat Conservation Trust hmcfarlane@bats.org.uk 02078207168.