Stoke Church bat walk 23/07/24
Introduction:
There are 18 species of bat in the UK of which 15 have been recorded within the Parish of Hartland.
Last year we discovered that Common Pipistrelle and Serotine Bat roost in the church; and four other species were recorded within Stoke.
Many thanks to Braunton Countryside Centre and the North Devon AONB team members for joining us and loaning bat detectors for the evening.
Species seen / recorded this year:
Common Pipistrelle - They probably roost between the roof slates and roof panelling inside the church; and can be seen flying inside the church before climbing over the top of the North porch door to emerge outside.
The first bat emerged at 21:12 and 405 recordings were made during the next hour; and were identified by tuning the detector to 45 kHz and listening for a wet slapping sound.
Some people heard the "feeding buzzes" made by the bat when it was about to catch insects; the sound resembled a dolphin call.
They were also recorded making social calls between them and other Common Pipistrelle bats.
Serotine Bat - Probably roosts around the gable end of the church in the roof space or wall voids.
The first bat was seen / detected at 21:44 around the East side of the church flying high and was noticeably larger than the Pipistrelle. They were detected by tuning the detector to 30 kHz and listening for an irregular hand clapping sound.
27 recordings were made of this bat echolocating over the next 15 minutes before it either returned to it's roost or flew off to hunt somewhere else.
What to look for in flight:
Look up into the sky to see bats silhouetted.
How big is the bat? Is it noticeably large?
Can you see the ears? Likely to be a long-eared bat
How high in the sky are they flying? Large species such as Noctule, Lesser Noctule and Serotine all fly high up around the same height as Swifts and Swallows.
How are they flying? Acrobatic flight or flying in a straight line and swooping down?
What are they flying over? Water, tree tops, around shrubs, within woodland or just above the ground.
Bat facts:
Bats are the only mammal capable of sustained flight and the earliest known fossils are from the Eocene approximately 52 million years ago.
Sound is produced by their voice box to navigate, hunt for food, socialise and provide warnings.
Human's can hears sounds up to a frequency of 20 kHz (20,000 Hz) and UK bats make sounds between 17 & 145 kHz.
Bat detectors have ultra-sonic microphones and they convert the sounds to a frequency that we can hear them.
The Common Pipistrelle can eat up to 3,000 insects in a night.
Nathusius's Pipistrelle hibernates in Eastern Europe and migrates to Britain in the summer travelling a distance of more than 1500 miles.
An adult female will rear one pup a year that is typically born in June and July.
The oldest recorded UK bat was over 30 years old.
Roosts are comparable to hotels; different species can live in roost sites and tree roosting species such as Noctule Bat can live in 20 different trees throughout a typical year.
In this part of North Devon most bat species are active throughout the year; although in mid-winter their feeding flights are limited to 30 minutes to 2 hours.
Bats will leave their roosts to feed etc providing it's not raining heavily or very windy; freezing temperatures is not a barrier to them being active since there are large numbers of moths, caddis flies and midges flying during mid-winter.
The Pipistrelle is the smallest UK bat having a body length of 35-45mm; wingspan of 200-235mm and weigh 3-8 grams.
The Greater Horseshoe is the largest with a body length of 57-71mm; wingspan of 350-400mm and weigh 17-34 grams.
The Serotine Bat that we saw has a long body that the Greater Horseshoe but a shorter wingspan.
Further info:
UK Bat species
Bat detectors
WildID - British Bats
British Bats Calls - A Guide to Species Identification by Jon Russ
Shebbear Bat Care - Please contact them promptly if you find an injured / exhausted bat and always wear gloves to handle them
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