Long-eared bats rule the roost

  Credit: Tom Marshall (taken under licence in controlled conditions)

Catching up with the Brown Long-eared bat colony at our Lings Nature Reserve in Northampton, as part of the annual roost count for the Reserve Bat Conservation Trusts National Bat Monitoring Programme.

We have just completed the 11th annual roost count of our Brown Long-eared bat colony at Lings House, our Northants office located in the middle of Lings Nature Reserve. The count is part of the Bat Conservation Trusts National Bat Monitoring Programme which monitors trends of 11 bat species across the UK and then publishes the State of the UKs bats report. Two counts are made in either half of June as the bats emerge shortly after sunset (or given our bats are a punctual bunch between 21.45 and 21.58). As well as the Brown long-eared bats which shoot off to gleam insects from the surrounding trees we regularly record noctule and common and soprano pipistrelle bats flying overhead. 

Year

Max Count

2008

12

2009

6

2010

19

2011

24

2012

18

2013

24

2014

21

2015

30

2016

27

2017

33

2018

28

 

Our counts show an increasing population over the years (having run out of fingers and toes in 2011 we had to invest in a tally counter) and we assume we have a maternity roost. Based on surveys in the last few years we estimated a healthy population of around 30, a sign that both the roost and Lings Wood are in a good condition.

Brown long-eared bats are medium-sized and as the name suggests their ears are nearly as long as the body.  As well as catching insects in free flight, brown long-eared bats are gleaners, often flying slowly amongst foliage, picking insects off leaves and bark. Their broad wings and tail allow slow, highly manoeuvrable, hovering flight. These bats are known as ‘whispering bats’ because their echolocation sounds are very quiet, making them hard to count as the evening darkens. Summer roosts are usually located in older buildings, barns, churches and trees with colony sizes of around 20 so ours is a large colony.

The UK estimated population of Brown Long-eared bats is 245,000, and based on roost count data the population is thought to be stable since 2001. This roost is one of 61 monitored roosts across the UK, and one of only a handful in the east midlands. This shows the importance of the roost monitoring programme. Even if you don’t know a local roost you can get involved through the BCT field or waterways surveys, which also contribute valuable data towards monitoring the status of our bat populations.