Probably Nathusius Pipistrelle over the House 31st March, 2017

With a mild overnight forecast, I ran the bat detector remotely in the back garden. Results were of limited quality due to the adjacent house wall, but species were identifiable. Both Common and Soprano Pipistrelle were recorded, the Common Pips triggering the detector frequently throughout the night.

A Noctule was picked up commuting over the house which was good. Then best of all a Bat detected at 23:48hrs caused great excitement as it's peak frequency was 35Khz. This has now been analysed, and I'm 99% sure it is a Nathusius' Pipistrelle, but so distant that a lot of the components of the calls are attenuated out of range.

(The only other option is a Savi's Pipistrelle, which would be pretty incredible with only a handful of UK records. I'd originally thought Batrbastelle, but this has been discounted by the county Bat recorder).

Distant (Probable) Nathusius Pipistrelle sonogram below.