The exodus was the culmination of an event organised at Gayton Thorpe, near King’s Lynn, by the Norfolk Bats In Churches Project.
Earlier we had listened to a presentation by Philip Parker of the Project who told us there were around 1,200 different species of bat in the world, that is to say they represented one in five of all mammals. There are 18 species in the UK.
Mr Parker and his team have found that 220 of Norfolk’s 700 mediaeval churches have a bat roost. He thought the bats found these churches to their taste because often being built of flint they had lots of spaces where the bats could squeeze in and also a lot of the churches were in dark places, which the bats preferred. Even in East Anglia only a small proportion of churches had large roosts.
In Gayton Thorpe, St. Mary’s Church has a moderately sized maternity roost consisting of 12 female common pipistrelles inside the building and an unknown number of soprano pipistrelles using a box specially placed on the exterior of the building. This meant quite a bit of clearing up was necessary, but the villagers worked round it, he said.
Mr. Parker commented that bats actually had very good eyesight but their main means of getting around in the dark was echolocation. A pipistrelle would eat around 3,000 midges and small flies – equivalent to about the bat’s own bodyweight – each night. This meant they were getting rid of insects that bit people and also that they were eating pests of agricultural crops. Bats could live for 20 years.
After the talk, Mr Parker set up his cameras and bat detectors ready to witness the bats’ departure into the countryside beyond for their nightly foraging trip.
We were also able to see some bats up close as some rescued ones had been taken along. It was amazing to see how tiny the common and soprano pipistrelles and the brown long-eared bat really were when held in someone’s hand; we usually see them when they are flying about and so they seem larger.
As the bats began to leave their roost, we could see them flying about inside the church fairly clearly because the walls had been painted white. And then we went outside to see if we could spot the gap through which they slipped outside. Throughout, we were able to hear the sounds the bats were making via the detectors.
St. Mary’s Church is an attractive building with a round tower, which was built in Saxon times, around 950 – 1000 AD. The top stage of the tower was restored by the Normans some 200 years later. The church underwent some major restoration work in 1900. Although churches with round towers are rare in Britain as a whole, there are 180 of them in East Anglia.
We were pleased to see there was a wildflower area prepared in a sunny spot in St Mary’s churchyard and that another part had been left to go wild. We spotted a pied wagtail foraging in the churchyard just after we arrived.
At home in the early afternoon, there was a different sort of treat to witness. Two buzzards were gliding about high in the sky over our garden, at the same time as a number of swifts – like bats, they are also insect hunters – were darting about after insect prey.
And I tried a final couple of bee hunts in the garden, spotting a white-tailed bee with two yellow bands and a tree bee. I forwarded the details to the Great British Bee Count, which also ended yesterday. I saw the juvenile blackbird, which I mentioned in an earlier post, on the back lawn, so it seems to have fledged. It has yet to grow a tail!