Soprano Pipistrelle Emergence

The footage below was taken on the 4th July 2022 at a site in Dorset, 37 minutes before sunset! This is well before the 15 minute start time of a bat activity survey following the good practice guidelines published by the Bat Conservation Trust (BCT) (Bat Surveys for Professional Ecologists: Good Practice Guidelines (3rd edn)). Species such as common pipistrelle and soprano pipistrelle often fly much earlier than 15 minutes before sunset in peak summer months, especially if the weather was sunny and dry during the day. This is why our surveys start a minimum of 30 minutes before sunset, and then continue for 90 – 120 minutes after sunset, in order to record as many emergences as possible.

The soprano pipistrelle is regarded as a crevice dwelling species not a void dwelling species (such as the lesser horseshoe) , which means it does not need an area large enough to hang upside down in. Soprano pipistrelle bats will often roost in areas such as lifted tiles, under hanging tiles and lifted flashing and in the eaves of buildings. The example below shows a soprano pipistrelle flying out from a small area of missing pointing at the end of the slate roof cladding.

Slow – motion footage Soprano pipistrelle emergence from the missing pointing at the end of the slate roof cladding, recorded on an infra-red camera.

Why do we use Infra-red Cameras?

Simply, because the benefit of using Infra-red cameras and illuminators greatly outweighs any reason not to use them. They are an additional resource which allows for greater accuracy in our activity surveys, giving us the ability to pinpoint the areas of emergence and to record those that may have been missed. Daniel Ahern Ecology has been using Infra-red cameras to support its emergence surveys since before the BCT published the Interim guidance note on night vision aids, and the company welcomes the future changes to good practice to ensure that the entire sector begins to use these devices more regularly.

Daniel Ahern Ecology

Home Farm House, Humber Lane, Tidworth, Wiltshire, SP9 7AQ
01980 842709
07880 551441

Get in touch