British Bats

By Sue Searle

Key Bat Facts

• 17 species breeding in the UK

• All of these are ‘Microchiroptera’

• Only flying mammals

• Long-lived – up to 30 years

• Pipistrelle is thumb-size

• British bats only eat insects

Bats around the World

• >950 species

• Almost ¼ of all mammal species are bats!

• Order Chiroptera – means hand wing

• Only mammals able to undertake powered flight

• Wing is formed from thin membrane of skin stretched

between the foot and the finger tips

Distorted truth!

‘As blind as a

bat’

•No British bats drink

blood – they eat

insects

•3 bat species

worldwide drink

blood from large

animals

•Only in Central and

Southern America

•Bats look like they are

baring their teeth when

they are echolocating

•However, if handled

they may bite as a

means of defence

Bats drink

blood – they’re

vampires

Bats are aggressive

– they bare their

teeth at you

•Not blind, but can’t

see in colour

•Fairly good night

vision – good

sensitivity rather than

good resolution

•Only 10 UK bats have

tested positive for

carrying rabies virus

•Over 6000 bats tested

since 1986

•Mainly Daubenton’s

Bats carry

rabies

Bats get in

your hair

Bats use Echolocation

to find their way

around. They do not

usually knock into

anything but

sometimes they make a

mistake!

Bat species in Britain

Vespertilonidae

3 pipistrelle species

6 Myotis species

3 ‘big bats’

2 long-eared bat species

Barbastelle

Rhinolophidae

Lesser horseshoe

Greater horseshoe

British Bats Pipistrelles

•3 species

•Britain’s smallest bats

•Crevice dwellers

•Common pipistrelles and

soprano .pipistrelles are Britain’s

..commonest bats

•Nathusius’ pipistrelle is rare but

..widespread

Soprano pipistrelle

Long-eared bats

•2 species

•Very long ears, joined at base

•Often roost along ridge beam in

buildings

•Brown long-eared bats are

..common and widespread.

•Grey long-eared bats are rare

..and restricted to Southern

..England

Brown long-eared bat

British Bats Myotis bats

•Largest genus in Britain – 5 species

•No post-calcarial lobe and paler fur on underside

•Crevice dwellers

Natterer’s

-Favours

..woodland

-Common and

..widespread

Daubenton’s

-’water bat’

-Common and

..widespread

Bechstein’s

-long ears

-Rare &.restricted -

Woodland sp.

Brandt’s and Whiskered

-very similar

-uncommon and not

in Scotland

Alcathoe's Whiskered bat

first discovered in 2010, smallest

bat in UK

British Bats Barbastelle

•Black bat

•Unmistakeable appearance

•Prefers ancient woodland

•Rare but wide ranging

•Southern England and Wales

Big bats

• 3 species

•Noctule: Largest British bat,

roosts in trees, common, not in

northern Scotland or Ireland.

•Leisler’s: Smaller relative of

noctule, common, stronghold in

Ireland.

•Serotine: Different genus,

shaggy fur and long tail.

Noctule Serotine

Leisler’s Barbastelle

Horseshoes

•2 species

•Distinctive nose leaf

•Hanging bats

•Greater horseshoe: pear sized,

..rare and restricted to south

..west England and Wales.

•Lesser horseshoe: plum sized,

..rare (less so than greater),

..south.west England, Wales and

west.midlands.

Greater horseshoes Lesser horseshoe

British Bats Any other bats?

• Vagrants blown over from

continent or arrive in

shipments of wood –

e.g. Geoffroy’s

•Greater mouse-eared bat. ..Only

one bat known in Britain.

Greater mouse-eared

bat

Echolocation

• Ultrasound pulse

from mouth or

nose

• Sound reaches

prey and is

reflected

• Using time of reflection, the bat can

calculate the distance

The Bat’s

Wing Thumb 1st finger

2nd finger

Tail

4th finger

Blood

vessels

3rd finger

• Can you

guess the

species?!

Bat Habitat • Roost sites – barns, houses, caves, trees…

• Ideally mosaic of woodland, slow moving/still water and grazed grassland

Good connectivity between roosts and feeding areas

(e.g. bushy hedges/tree lines)

Different species have different habitat

preferences

The Bat’s Year

Bat Roosts

• Bats roost in trees, buildings, caves and

under bridges

• Only horseshoe bats actually hang

The Signs

• Piles of droppings

• Moth wings

• Greasy marks

• Gaps under eaves and in roof, and

no cobwebs in them

Where would bats be roosting in a

house?

Types of roosts

Hibernation

Summer

Night roost or feeding

perch

Maternity

Transitional

Mating

Bat Roosts

Pipistrelles

Lesser

horseshoes Brown long-eared

and pipistrelle

Lesser

horseshoes

Lesser

horseshoes

Lesser

horseshoes

Brown long-

eared

Serotine

Tree roosts

Trees – splits, fissures

woodpecker holes, behind

ivy stems

Man-made bat boxes

Veteran trees (roosts)

Bat Droppings

Mouse

or bat?

Hard Crumbly

Survey Timings and Effort

Survey

objective

Dusk survey Dawn survey

Bat activity away

from the roost

Sunset to 2-3 hours

after sunset1

2 – 1 ½ hours before

sunrise to sunrise

Bat emergence

from and re-entry

to roost

¼ hour before sunset to

1 ½ - 2 hours after

sunset2

2 – 1 ½ hours before

sunrise to 15 minutes

after sunrise3

Mating activity Sunset to 4 hours after

sunset

-

1 when site is larger than 1 ha and within 4 km of greater horseshoe bat roost, 3

hours is required.

2 Some bats may emerge earlier than ¼ hour before sunset.

3 Some bats may return to their roost after sunrise.

From BCT Good Practice Guidelines

Seasonality

J F M A M J J A S O N D

Bat activity surveys

Optimal period Sub-optimal period

Dusk emergence and dawn re-entry surveys

J F M A M J J A S O N D

Bat Conservation

• Bats have seriously declined

• Greater and lesser horseshoe endangered

• Nine other species are threatened

Reasons…

• Loss of roost sites

• Chemical timber treatment

• Decline of prey species

• Loss of hunting grounds

Bat Protection & Conservation

• Bats are fully protected by several pieces

of legislation

• Together they prevent intentional killing,

injuring or capture, disturbance and damage

to a roost site.

• Licences are required

• Conservation: roost protection, regulation of

building work, control of pesticide use

• Bat Conservation Trust

References

Bat Conservation Trust (2016). Bat Surveys – Good Practice Guidelines (3rd

Edition). Bat Conservation Trust, London

Mitchell-Jones A.J. and McLeish A.P. (2004). Bat Worker’s Manual (3rd Edition).

JNCC