Nyctalus leisleri     Nlei

Similar calls to Common Noctule but in somewhat higher pitch.
In the open, QCF around 23 kHz and duration well under 20 ms, often 15 ms. Intervals often 200-250 ms.
When active, not as variable as N. nyctalus. Emax altering well above 20 kHz.

This is a typical recording of QCF calls.

Durations 11 -15 ms:

Two species are using QCF calls just above 20kHz, Lesser Noctule and the Parti-coloured bat.
The shape of the Parti-coloured is a bit curved in the start while the lesser noctule has a more straight formed call.

The recording below looks like the Lesser N (Emax = 23 kHz and duration 16 ms) but you will never know for sure.

NleiM00069, 150619 03:04:03 Lillehem, SWEREF99: N:6181827 E:442816 Google Earth