For some years, Friends of Abbey Fields has hosted an annual “Bat Walk” (also referred to as our “Bat Evening”). Warwickshire Bat Group usually take the lead in educating us about these marvellous mammals.
Little and Large
Among the largest bats in the world are the group commonly known as “Flying Foxes” found in Southeast Asia and Australia. These bats can weigh up to 1.6kg with a wingspan of up to 1.5m. At the other end of the scale are Kitti’s Hog-Nosed Bats, also known as Bumblebee Bats. This is a threatened species found in Thailand and Myanmar. It is the smallest species of bat and arguably the world’s smallest mammal. These bats typically weigh 2g with a wingspan of 17cm.
Of the 1250 known species, we have about 18 in the United Kingdom, all of which feed on insects (there are no vampire bats here). The smallest bat in the UK is the Pipistrelle, and the largest is the Noctule. Even the tiny Pipistrelle eats up to 3,000 midges per night!
Male bats tend to be solitary, whilst female bats roost in Maternity Roosts until the autumn when they fly off to join the males who often have harems! The female stores fertilised eggs until spring when the ‘pups’ – baby bats – are born. Usually, only one pup is produced by a female each year.
In the Abbey Fields
You will likely see Common Pipistrelle Bats, Soprano Pipistrelle Bats, Noctule Bats, Brown Long-Eared Bats, and Daubenton’s Bats in the Abbey Fields. They like to roost in crevices in buildings, trees, roof spaces, bat boxes and other similar spaces.
During our Bat Walks, we use handheld Bat Detectors, which allow us to listen to the bats locating and catching insects and some of their calls to one another while in flight. Bats communicate or detect using high-frequency sounds (ranging from 15 – 125kHz). Without bat detectors, we would be unable to hear the bats – the detectors convert their sounds to frequencies within the human range.
In the evening, Common and Soprano Pipistrelles can fly low among the trees, over the Abbey Fields Lake, and circling and swooping in the darker areas around the graveyard. As the bats home in on their food, the detectors give out a short burst of sound.
In the UK, all bats hibernate. Some bats migrate from Estonia to the UK in winter and return to Estonia for summer – quite a journey with a big sea crossing!
Did you Know?
- Bats are the only mammals that can truly fly
- Bats are predated upon by owls, hawks, cats and even Great Tits (if they are very hungry)
- Bats generally live between 10 – 20 years, but 1 individual was recorded as living over 40 years!
- In winter bats hibernate in cool buildings, caves or hollow trees
- Britain’s commonest bat, the Pipistrelle, is only 4cm long and weighs about 5 grams – less than a 2p coin. With its wings folded, it can fit inside a matchbox!
- 12 of the 16 bat species found in Britain are either endangered or vulnerable
- Bats are useful for pollination and seed dispersal
Bats in the UK are in serious decline. The use of insecticides is killing their food sources, and their roosting habitats are under threat due to trends in building construction.
Over the years, Friends of Abbey Fields have sponsored installation and maintenance of Bat Boxes in the Abbey Fields in order to encourage an increase in the bat population. Only people with the appropriate licence issued by the government organisation Natural England are allowed to open the boxes!
Bat Box Installation 2004
In March 2003, we asked our members for donations towards providing bat boxes in the Abbey Fields, which proved very successful. The boxes were made for us by the Warwickshire Bat Group and were erected by their volunteers and Warwick District Council Arboricultural team.
In September 2004, Paul Elliot, John Waller and Jackie Underhill from the Warwickshire Bat Group inspected the bat boxes. Each box was marked with a number for future identification and then checked for occupancy. Because the young bats had gone from their parents’ roosts to find their own favourite place, Paul and the others were looking more for signs that bats had been in residence rather than the bats themselves. They found bat droppings in six of the boxes, and one of them, on a large oak to the north of the lake, actually contained a bat, which was thought to be a Soprano Pipistrelle.
- The Warwickshire Bat Group
- The Bat Conservation Trust
- Review the FOAF Newsletters that feature bats
- Reports on FOAF Bat Evenings
Thanks to Dr Jon Russ (Ridgeway Ecology), Julia Waller and Tricia Scott (Warwickshire Bat Group), Celia Rickers, and David Emsley for contributions to this page.