Bats

Bats are the only true flying mammal. There are 1,500 species of bats in the world (as of September 2025), and more are still being discovered. Bats account for more than a quarter of mammal species in the UK and around 20% of all mammal species worldwide.

There are 18 resident bat species in the UK and they make up almost a quarter of our British mammal species

Conservation and Threats.

In the UK, bat populations have declined considerably over the last century. Bats are still under threat from building and development work that affects roosts, loss of habitat, the severing of commuting routes by roads and threats in the home including cat attacks, flypaper and some chemical treatments of building materials. Other potential threats can include wind turbines and lighting if they are sited on key bat habitat on near roosts.

Bats found in Highfield Park –

Ultrasonic bat calls were recorded at three locations in Highfield Park, using an Audio Moth bat detector, between September 21st and October 5th, 2021 and then again in August 2022 at a third site, by M E Clarke.

Recordings were made for 10 nights at site HP01, at the edge of the Cell Barnes pond, 10 nights at site HP03 at the Cell Barnes grasslands and for 5 nights at HP02, a mature tree next to areas of young trees in Hither Wood.

The detector turns on shortly before sunset and off shortly after sunrise and records a 10 second file whenever it is triggered by a sound greater than about 15kHz. The files are inspected using analysis software and each file is labelled with the name of the species identified with the calls shown. The number of files for a species is a measure of the species activity and corresponds broadly with the number of times a bat passes within detection distance (usually up to 20 or 30 metres).

The results for the three sites are summarised in the table below:

Table 1: The number of files counted for each species at each of the three sites

A few notes are given here on each of the species recorded. More information on these species can be found at: http://www.bats.org.uk/pages/uk_bats.html

Common pipistrelle (pipistrellus pipistrellus): These are the commonest and smallest of British bats. There was evidence of heavy foraging over the pond at site HP01 but there was little evidence of feeding (feeding buzzes) at the other site which suggests that the pipistrelles there were feeding in the general area of the detector at HP02.

Soprano pipistrelles (pipistrellus pygmaeus): are similar to the common pipistrelles but distinguished by a higher frequency echolocation call. They seem to prefer woodland and tend to be recorded in higher numbers there than in more open areas. At HP01 the calls were mostly rather faint indicating that they were flying and foraging some way from the detector.

Brown long ear (plecotus auritus): This is another very common British bat but is recorded in much smaller numbers than the pipistrelle species. It often uses a quiet call and feeds by gleaning in tree foliage as well as by echolocation. Only a single pass was recorded at HP01 and none at HP02.

Natterer’s (myotis nattereri): It can be difficult to distinguish between the six UK species of myotis bat by their echolocation calls but the Natterer’s bat can usually be identified by the exceptionally wide frequency range, from about 20kHz to well over 100kHz. In the recordings at HP01 the myotis files are clearly Natterer’s.

Noctules (nyctalus noctula): The noctule is the largest UK bat. It is recorded quite widely in the open countryside and tends to feed on larger insects in more open areas than the smaller bats. Only a few “fly by” passes were recorded at the two Highfield sites