After last week's busy National Insect Week and its launch in the Wildlife Garden on 23 June, we turned our focus onto some important insect predators... bats! We're celebrating the amazing world of these flying mammals at our annual Bat Festival this coming weekend; an event hosted in partnership with the Bat Conservation Trust and with the London Bat Group.
There are over 1,200 species of bat in the world; some are vegetarian and eat fruit and nectar, some eat fish or small mammals including frogs but, like all 18 species known to live in the UK, the majority feed on insects.
These UK bats mainly catch their insect prey in flight. Some such as the Daubenton's bat will also take insects from the surface of large ponds and rivers, and a few including the brown long-eared bat will sometimes glean or pick their insect food from leaves and bark, or even from the ground.
Daubenton's bat in flight over water
© Kevin Durose, Bat Conservation Trust
Brown long-eared bat - also called the whispering bat - looking down from its roost in an old cottage
© Sean Hanna, Kent Bat Group
Bats seen in the Wildlife Garden at dusk are the common pipistrelle (Pipistrellus pipistrellus) and soprano pipistrelle (Pipistrellus pygmaeus). It's a special moment to watch them feeding over the ponds and meadow areas where they catch small moths, caddisflies, midges and other small flies. There are also probably brown long-eared bats in the trees, but their ultrasonic calls are usually too quiet to hear on a bat detector.
Pipistrelle bat in flight
© Hugh Clark, Bat Conservation Trust
Many of these insects start off life in ponds including caddisflies and non-biting midges, and their larvae are often found during pond dipping sessions.
Yellow spotted sedge caddis fly (Philopotamus montanus)
Its larvae are found in fast flowing rivers and streams rather than in wildlife garden ponds!
© Emma Ross
Caddis fly larvae from our pond - find out more about caddis fly larvae cases this weekend
© Larissa Cooper
While the Garden is the Museum's only permanent living exhibition with its collection of native plants and associated wildlife - including insects and bats -the Museum is, of course, renowned for its huge collection of specimens from around the world. Again, this includes bats. Mammals Curator, Louise Tomsett tells us more about these fascinating animals from a curator's perspective:
"There are over 30,000 bat specimens in the collection. Most of our collections are from mid-late 1800s and first half of 1900s.
We have an estimated 95% coverage of species but bat taxonomy is in constant flux so there may be undiscovered species present in the collection. It has happened several times in the collections.
Dry bat skins in the reference collection
© Louise Tomsett
The collection is rich in species variety, geographic range and historical specimens. The collection is particularly important for conservation. Researchers access the specimens to gather information to create an identification guide that is then used in biodiversity surveys.
The geographical locality information associated with the specimens also gives insight to where populations are or where they used to be and can be used to assess declines or changes in species range. Presence of a bat in a particular area also indicates the type of environment and other associated species such as insect prey.
Type specimens in the reference collection. Types are the representative specimens that display characteristics that define that particular species. Descriptions of species are based upon these individuals and they are used as comparative examples when researchers are attempting to designate a new species.
© Louise Tomsett
The collections are sampled for a wide range of genetic research. These samples can provide information on population genetics and may be used in association with living samples to assess inbreeding in populations and support conservation genetics.
The reference collections are kept behind closed doors in special storage areas, with controlled access. This is to prevent fading from light exposure and as protection from dirt, unnecessary handling and from pests that would destroy them.
The job of a curator is to provide access for multidisciplinary research but also to balance this use with preservation for the future as the collections are irreplaceable. Each specimen is a unique example of an animal from a specific time and place. They need to be preserved for future generations.
History has shown us that the collections hold a wealth of undiscovered information and new research techniques to unlock this are being developed all the time. We cannot always predict what research or type of information a specimen will be used for."
To see some of these unique specimens from around the world and to discover more about bats at home - their diet, lifestyle and habitats - join us in our Bat Festival this weekend, 5 and 6 July from 12.00 to 17.00 each day.