National Nathusius’ Pipistrelle Project

What is the NNPP?

It is thought that the Nathusius’ pipistrelle is a rare species in the UK however it is also an under-recorded species.

Migration patterns of Nathusius’ pipistrelle are relatively well known in mainland Europe but the movements of bats in and out of the UK and their migration routes and origins are not known.

The NNPP was launched to improve our understanding of this elusive species by finding out more about it’s migratory routes and resident & breeding status of this bat in the UK.

Bat groups across the UK are involved with this project, and all the work is done under licence.

How does it work?

There are four main methods for this survey:

  • Identify hotspots of Nathusius’ pipistrelle activity using acoustic bat detector surveys.
  • Using harp traps and acoustic lures (see images below) in activity hotspots, trap individuals under licence and ascertain their breeding status, collect a dropping, a fur sample and ring each individual.
  • If females are captured in the pre-breeding period, undertake radio tracking to locate potential maternity roosts.
  • Stable isotope analysis of fur samples to determine latitudinal provenance and assess migration patterns of the bats.

All data that is collected as part of the survey is sent to the Bat Conservation Trust for analysis

What is a Nathusius’ pipistrelle?

Nathusius’ pipistrelle is a migratory species, and most bats are encountered in autumn, although some do remain all year and breed in the UK. It is similar in appearance to, but slightly larger than the much more commonly found common and soprano pipistrelles, and the fur on its back is longer, sometimes giving a shaggy appearance.

Echolocation calls of Nathusius’ pipistrelle are similar to those of the other pipistrelles. The peak intensity of the call is lower than the other two species, however, at about 38kHz.

Nathusius’ pipistrelle (female) in South London, 2019

What are we doing in London?

London Bat Group first joined the project in 2016 and we had a training day with bat expert Daniel Hargreaves.

We first identified activity hotspots in London for Nathusius’ pipistrelle through acoustic surveys. We then used this information to select our survey sites. At our selected sites we initially look for suitable location to set up harp traps and lures, ideally this would be close to a body of water and sheltered. (picture of harp trap set up). The survey starts at sunset, we turn the lures on and wait for bats to show up!

Although our target species is Nathusius’ pipistrelle, we still process any other species we trap. Processing involves sexing, ageing and identifying the species of the bat. When a Nathusius’ is trapped, we take extra details to confirm the species ID.

If it is a female Nathusius’ pipistrelle, this bat is ringed by an experienced bat worker. We ring bats to find out more about the migratory patterns and behaviour.

Nathusius’ pipistrelles trapped in London – female (left) and male (right)

Results

Two bats from Latvia turned up in Greater London in August and September 2017 (the minimum distance travelled for this migration is 1,490km!)