Pipistrellus pipistrellus Ppip
The Common pipistrelle is a close relative to the Soprano pipistrelle. They were regarded the same species earlier but they differ in Emax frequency. A pipistrelle below 50 kHz can be a Common pipistrelle and it can be as low as 42 kHz. So there is an overlap with the Soprano as well the Nathusius’s. The intervals between calls at normal hunting is well below 100 ms.
Here is a recording with Emax at 45 kHz and intervals 90 ms. Nice and clear.
This recording also contains some very weak calls from a Soprano pipistrelle.
Emax is about 45 kHz but there are longer intervals. Can it be a Nathusius’s?