Bats in Hertfordshire & Middlesex

There are approximately 18 species of bat in Britain*, but only 10 are regularly found in Hertfordshire and Middlesex. Another two species (Whiskered and Brandt’s) have been recorded, but very rarely [*One species is, as far as we can tell, extinct as a breeding species. One or two others may be breeding although there is no conclusive evidence. This uncertainty demonstrates how little we know about our native bat populations].

The Common and Soprano Pipistrelles are the most widespread. They are the bats you are most likely see flying around your garden shortly after sunset. They are also amongst our smallest bats weighing less than a sheet of A4 paper and fitting comfortably into a matchbox. Even the largest British bat, the Noctule, only weighs as much as two 50 pence coins.

More information on each species of British Bat can be found at the Bat Conservation Trust’s website:


Bats you can find in Hertfordshire & Middlesex are:

Common Pipistrelle – Widespread, occasionally common. One of the two species most likely to be encountered.

Soprano Pipistrelle – Widespread, occasionally common. One of the two species most likely to be encountered.

Nathusius’ Pipistrelle – Widespread, but still considered scarce. Usually recorded foraging over large water bodies.

Brown Long-eared – Widespread, relatively frequent but not often encountered outside of roosts.

Daubenton’s – Widespread, relatively frequent near still water.

Natterer’s – Widespread, relatively scarce.

Whiskered and Brandt’s – Very few records and so assumed to be rare.

Serotine – Widespread, but scarce.

Leisler’s – Widespread, but scarce.

Noctule – Widespread, but relatively scarce.

Barbastelle – Limited to a few wooded river valleys, where rare.

We welcome records of bats from anyone with sufficient experience to identify to species level. These records will be used to inform planning applications, improve our understanding of bat distribution across the county and guide future conservation and survey effort. If you have recorded bats in Herts or Middlesex, please use our online form (Herts and Middlesex bat record online submission form) to submit your record. Once submitted, these records will be verified and then added to our database and subsequently shared with the Hertfordshire Environmental Records Centre (HERC).