This document provides information about identifying bat species through their physical characteristics such as size, coloration, ear shape, and habitat. It includes descriptions and photos of 15 North American bat species commonly found in the eastern United States. The intended audience is bat rehabilitators and enthusiasts. The creator requests photo credits when sharing the document.

1. By The Save Lucy Campaign
www.saveLucythebat.org

2.  Slide show is intended for bat rehabilitators and bat
enthusiasts. Please feel free to distribute, but be nice
and credit the source.
 This is a work in progress. Species will be added as
photos are procured.
 In a very few instances, photo credit is unknown. If we
have used a photo that belongs to you or your
agency, please let us know who to credit. Thanks in
advance!
 All other photos belong to Rich Sturges and/or The
Save Lucy Campaign.

4. FACE
Muzzle
Broad? Narrow?
Bald? Furred?

5. EARS
Shape
Narrow? Rounded?
Length
Short? Long?

6. Tragus
The narrow element
in the ear
Important in telling
Myotis spp. apart

7. BODY
Size
Weigh!
Measure nose to tail
Coat
Color
Some have banded fur
Color varies with age and
among individuals
Length
Furred tail membrane?
Furred wrists?

8. SIDE VIEW
Color of dorsal vs.
ventral fur
Color of wing, tail
membrane

9. FOREARM
Measure!!
For the love of all
that is holy, measure
the forearm!!!
Over 40mm and
brown =
big brown bat

10. FOOT
If forearm is less
than 40mm, might
need to measure foot

11. ToeHairs
For brown bats with
forearms under
40mm, might need
to examine toe hairs
Copious?
Long?
Usually need
magnification and
very good light to see

12. Keel
For brown bats with
forearms under
40mm, might need
to look at calcar
Yes!!
No!!

13. Bats!!

14.  Short, rounded ears
 Broad, bald muzzle
 Forearm OVER 41 mm
 16—20+ grams; 14 inch wingspan
 Nonmigratory
 Uses buildings summer and winter
 Also uses caves and mines for
hibernation
 Beetle eater
 2 young per year born late
May early June
 Lifespan 15—18 years

15.  Long, narrow ears
 Sharp, furred/whiskered muzzle
 Forearm 34—41 mm
 7—9 grams; 9inch wingspan
 Highly variable in color and body size.
 Often uses buildings or barns in
summer
 Migrates to caves in winter—may
move 200+ miles to reach appropriate
hibernacula
 Forms large colonies
 May roost with other myotis species
 One pup per year
 Lifespan 30+ years
PAGameCommission

16. Big Brown Bat Little Brown Bat

17.  ENDANGERED
 Uses building roosts, but also
associated with old trees with
sloughing bark
 Is known to roost with Little
Brown Bats
 Same size and very similar
appearance to Little
Brown Bat
 Nose is slightly shorter; face
has a pinkish cast;
keeled calcar; sparse, short
toe hairs; small foot
 Migrates to caves for winter; recovered over
200 miles from banding sites
Courtesy: John Chenger, Bat
Conservation & Management, Inc.
Courtesy: NY DEC
Courtesy:JohnChenger,Bat
Conservation&
Management,Inc.

18. Photo by Adam Mann, Environmental Solutions and
Innovations
Little Brown Bat Indiana Bat

19.  Proposed for ESA listing
 Extremely long, narrow ears extend 4mm
past nose when pushed forward
 Narrow, sparsely furred muzzle
 Horizontally striated tail membrane is diagnostic
 Forearm 32—39 mm
 7—9 grams; 9 inch wingspan
 Very similar in
appearance to Little Brown Bats
 May roost with other myotis
species or in small colonies of
conspecifics.
 Found in deck umbrellas, tree hollows,
loose siding
 Thought to migrate to caves for winter
BUT new information suggests this
may not be true

20. Little Brown Bat Northern Long Ear Bat
B. Crokus

21.  ENDANGERED
 Somewhat larger than other
Myotis species
 6—13 g; 40—46mm forearm
 Woolly gray or russet fur
 Hair is solid color base to tip
 Membrane attaches at ankle;
claws are notched
 Uses caves year round, but moves
to three distinct cave roosts:
hibernation, nursery, summer

22.  Gray to bright brown fur
 5—8 g ; forearm 36—40mm
 10 in wingspan
 Belly fur markedly lighter
than dorsal fur
 Pinkish face, wooly fur
 Southern coastal areas; Great
Dismal Swamp
 Not common
Smithsonian Museum of Natural HIstory

23.  Distinctive black mask
 Smallest bat in region
 3—5g; wingspan 8.5—9.5 in
 Forearm 30—36mm
 Foot is only 8mm; keeled calcar
 Associated with scree and talus
slopes
 Western, mountainous areas
 Rare across range
 Dependent on puddles and road
ruts for drinking water

24.  Small bat, but looks like big
brown bat
 6—12 grams, 9—10 in
wingspan
 Forearm 33—39mm
 Tragus short, curved, rounded
 Usually uniformly dark
 Range is mainly south of LBB’s
but overlaps in mid-Atlantic
 Uses buildings in summer
 No one knows what they do in
winter, but one was recovered
from a moving box in winter.
Possibly had been in attic.

25. Evening Bat
Little Brown Bat

26.  Formerly Eastern pipistrelle
 Very small bat with reddish
brown fur and red forearms
 6—8 g; up to 9 in wingspan
 Forearm 31—35 mm
 Long, pointed ears
 Banded fur; dark, light,
dark
 Forms small maternity
colonies in tree hollows
and sometimes
under decks and open
barn lofts
 Has twins; pups are under
1 g at birth
 Migrates to caves for winter
 Often killed at turbine sites

27.  Very distinctive; black or deep
chocolate brown with silver tipping
on dorsal fur. Face, ear, and facial fur
are uniformly dark.
 Medium sized ; 8—12g
 Forearm 37—44mm; wingspan 11 in
 Not usually associated with
buildings, but have been recovered
from open sheds and garages during
winter
 May enter caves on occasion
 Form small maternity colonies
in tree hollows in northeast or in
higher elevations in mid-Atlantic
 Considered highly migratory;
found dead at wind turbines

28.  Very distinctive; buffy, gray,
& rust fur; black points;
short, rounded ears with black rims
 Forearm 46—58mm; 16 in wingspan
 Largest North American Bat;
20—38 grams
 Migratory; may move from
Canada to Mexico; overwinters in
mid-Atlantic; lactating female
recovered in Haymarket, VA in 2013
 Foliage bat; does not use
buildings
 Highly impacted by wind
turbines

29.  Buffy, sandy, or red with short,
rounded ears
 Medium sized bat; 9—15g
 Forearm 35-45mm; 12 in
wingspan
 Males are smaller and more
brightly colored
 Highly migratory;
common wind turbine
victims
 Foliage bat; does not
use buildings
 Solitary; raises young
in tree foliage
 Mates on the wing
 Often hit by cars
 Prone to window strikes
 Blue Jays prey on mothers with young

30.  Very similar to red bats
 Deep russet
fur, mahogany colored
skin
 10—15 g; forearm 35—45
mm
 12 in wingspan
 Known from the
southern coastal regions
SmithsonianMuseumofNaturalHistory
Mammalwatching.com

31.  Pale yellowish fur
 Larger than reds or
Seminoles
 18—24g; forearm 45—56
mm
 Wingspan 14—15 in
 Only recorded from one
county in SE VA
John Abbott

32.  ENDANGERED
 Lumpy nose
 Ears more than 1” long
 9—12 g
 Cave dependent year round
 Very sensitive to
disturbance
 Virginia state bat!
 State ENDANGERED
 Very similar to VBEB
 Ears more than 1” long
 8—14 g
 Highly associated with tree
hollows in swamps, but
uses other habitats in range