Refe

renc

esAn

thony

, ELP

and T

H Ku

nz.

1977

. Fee

ding s

trateg

ies of

the l

ittle b

rown

bat,

Myo

tis lu

cifug

us, in

south

ern N

ew H

amps

hire.

Eco

logy.

58:77

5-78

6.Ba

rbou

r, RW

, and

WH

Davis

. 196

9 . B

ats of

Ame

rica.

The

Univ

ersit

y Pre

ss of

Ken

tucky

.Ba

rclay

, RMR

2003

. Per

sona

l com

munic

ation

Brigh

am, R

M, H

DJN

Aldr

idge,

and R

L Mac

key.1

992.

Varia

tion

in ha

bitat

use a

nd pr

ey se

lectio

n by Y

uma b

ats, M

yotis

yum

anen

sis.

Chru

szcz

BJ,a

nd R

MR B

arcla

y. P

rolon

ged f

orag

ing bo

uts of

a so

litary

glean

ing/ha

wking

bat,

Myo

tis e

votis

.Can

adian

Jour

nal o

f Zoo

logy.

81: 8

23–8

26Ga

spar

i, M.

1994

. Rep

ort o

n bat

Stud

y at th

e W

ooda

rd B

ay N

atura

l Res

ource

Con

serva

tion

Area

. Unp

ublis

hed r

epor

t to W

ash.

Dept.

of N

atura

l Res

ource

sHa

rris,

AH. 1

974.

Myot

is yu

mane

nsis

in int

erior

south

weste

rn N

orth

Amer

ica, w

ith co

mmen

ts on

Myo

tis lu

cifug

us. J

ourn

al of

Mamm

alogy

55:51

2-51

3.He

nry,

M, D

W T

homa

s, R

Vaud

ry, an

d M C

arrie

r. 20

02. F

orag

ing di

stanc

es an

d hom

e ran

ge of

preg

nant

and l

actat

ing Li

ttle B

rown

bats

(Myo

tis lu

cifug

us).

Jo

urna

l of

Mamm

alogy

. 83:7

67-7

74Jo

hnsto

n, D.

2002

. Data

colle

ction

proto

col -

Yuma

bat

(Myo

tis yu

man

ensis

). Sa

n Fra

ncisc

o Estu

ary W

etlan

ds R

egion

al Mo

nitor

ing P

rogr

amNa

gorse

n, DW

. 199

3. Ba

ts of

Brit

ish C

olumb

ia. R

oyal

Britis

h Colu

mbia

Muse

um H

andb

ook

Orms

bee,

P. 20

03. U

SFS,

Eug

ene,

Oreg

on. p

erso

nal c

ommu

nicat

ion.

Schir

ato, G

, 200

3 pe

rsona

l com

munic

ation

Do

Larg

e C

olon

ies

Cre

ate

Lon

g C

omm

ute

s? E

xam

inin

g M

yoti

sB

at F

orag

ing

Dis

tan

ce a

nd

Du

rati

onG

reg

Falx

a, C

asca

dia

Res

earc

h C

olle

ctiv

e, O

lym

pia,

Wa.

g

regf

@ef

n.o

rg

Intr

oduc

tion

Eac

h sp

ring

and

sum

mer

the

larg

est k

now

n ba

t co

lony

in W

ashi

ngto

n st

ate,

a m

ixed

-spe

cies

mat

erni

ty

colo

ny o

f Litt

le b

row

n an

d Yu

ma

bats

(Myo

tis lu

cifu

gus

and

M. y

uman

ensi

s, o

r "M

YY

U/L

U")

roos

t in

an

aban

done

d ra

ilroa

d pi

er n

ear O

lym

pia,

Was

hing

ton

(Fig

s.

1 &

4).

The

bat

s be

gin

arriv

ing

in A

pril,

hav

e th

eir y

oung

in

ear

ly J

une.

Afte

r the

you

ng b

ecom

e vo

lant

in e

arly

Jul

y th

e co

lony

pea

ks a

t ove

r 3,0

00 in

divi

dual

s, th

en b

egin

s a

stea

dy d

eclin

e as

the

bats

dis

pers

e on

ly a

few

rem

ain

by

Sep

tem

ber.

Bas

ed o

n ex

amin

atio

n of

bat

s in

the

the

hand

, it

appe

ars

that

nea

rly a

ll of

the

bats

roos

ting

in th

e pi

er a

re

Yum

a ba

ts o

r Litt

le b

row

n ba

ts (G

aspa

ri 19

94) b

y ex

amin

ing

the

skul

ls o

f spe

cim

ens

(Sch

irato

200

3, p

ers.

co

mm

) and

in 2

004

by th

e au

thor

col

lect

ing

time-

expa

nsio

n ca

lls w

ith a

Pet

ters

son

D24

0x u

ltras

onic

de

tect

or a

nd a

naly

zing

the

calls

with

Son

oBat

sof

twar

e (P

ette

rsso

n E

leck

troni

k, S

wed

en &

Son

oBat

, Arc

adia

, C

A.).

In

the

coas

tal P

acifi

c N

orth

wes

t the

se 2

spe

cies

are

ex

trem

ely

diffi

cult

to d

istin

guis

h by

mor

phol

ogic

al fe

atur

es

(Har

ris 1

974)

and

iden

tific

atio

n be

twee

n th

ese

two

in th

e ha

nd is

unr

elia

ble

with

out t

he a

id o

f gen

etic

ana

lysi

s or

tim

e ex

pans

ion

call

anal

ysis

(Pat

Orm

sbee

, per

s. c

omm

.).

Bot

h Yu

ma

bats

and

Litt

le B

row

n ba

ts fo

rage

in o

r nea

r rip

aria

n ar

eas

whe

n th

ey a

re a

vaila

ble,

feed

ing

heav

ily o

n aq

uatic

em

erge

nt in

sect

s (B

righa

m e

t al.

1992

); an

d th

is

stud

y su

ppor

ts e

arlie

r rep

orts

that

the

se tw

o sp

ecie

s w

ill

use

sim

ilar r

esou

rces

for m

ater

nity

roos

ts (N

agor

sen

&

Brig

ham

199

3).

The

roos

t are

a is

bor

dere

d by

sal

twat

er in

lets

of

Pug

et S

ound

to th

e no

rth a

nd e

ast,

sem

i-rur

al o

pen

and

woo

ded

land

to th

e so

uth

and

wes

t whi

ch th

en tr

ansi

tions

in

to u

rban

are

as 8

-10

km fr

om th

e m

ater

nity

roos

t. W

e ex

pect

ed th

ese

bats

to fo

rage

at a

ser

ies

of p

onds

and

w

etla

nds

loca

ted

2 an

d 6

km to

the

sout

h of

the

roos

t and

fo

r the

ir ni

ghtly

act

ivity

alte

rnat

e be

twee

n bo

uts

of fo

ragi

ng

and

perio

ds o

f nig

ht ro

ostin

g. T

his

nigh

tly p

atte

rn is

wid

ely

repo

rted

for i

nsec

tivor

ous

bats

. Bot

h of

thes

e as

sum

ptio

ns

gene

rally

pro

ved

to b

e w

rong

for t

his

grou

p.

Met

hods

We

mon

itore

d th

e m

ater

nity

col

ony

popu

latio

n w

ith fl

yout

(em

erge

nce)

cou

nts

from

late

Mar

ch to

ear

ly O

ctob

er, 2

003

and

2004

. We

capt

ured

bat

s le

avin

g th

e pi

er w

ith m

ist n

ets

on 1

6 ni

ghts

bet

wee

n m

id-A

pril

and

late

Aug

ust b

oth

year

s.

We

used

Ski

nBon

d ad

hesi

ve to

atta

ch ra

dio-

tags

with

a 1

2-da

y ba

ttery

life

(.36

gr

am L

B-2

N, H

oloh

il S

yste

ms)

to 4

pre

gnan

t and

6 p

ost-l

acta

ting

bats

. We

gath

ered

an

aver

age

of o

ver 8

nig

hts

of fo

ragi

ng a

nd n

ight

roos

ting

beha

vior

pe

r rad

io-ta

gged

bat

. To

per

mit

inte

nsiv

e m

onito

ring

of th

e su

bjec

ts’ a

ctiv

ities

on

a fi

ne s

cale

, onl

y on

e ba

t was

radi

o-ta

gged

at a

tim

e. T

rack

ing

was

ac

com

plis

hed

by fi

rst e

stab

lishi

ng v

icin

ity lo

catio

ns u

sing

a v

ehic

le o

utfit

ted

with

a Y

aesu

FT-

817

ham

radi

o (V

erte

x-S

tand

ard,

Cyp

ress

, CA

) , o

mni

-di

rect

iona

l gai

n an

tenn

a, lo

w-n

oise

pre

ampl

ifier

, and

dig

ital a

udio

pro

cess

or (t

o re

duce

igni

tion

nois

e) .

The

obse

rver

then

sw

itche

d to

a p

orta

ble

tele

met

ry

rece

iver

and

use

d a

eith

er a

3 o

r 4-e

lem

ent h

andh

eld

Yagi

ant

enna

to o

btai

n di

rect

iona

l inf

orm

atio

n an

d "w

alk-

in" l

ocat

ions

on

the

bat.

Whe

n a

tagg

ed b

at's

si

gnal

was

lost

or c

ould

not

be

hear

d, a

sea

rch

patte

rn w

as in

itiat

ed fr

om it

s la

st k

now

n lo

catio

n. R

e-ac

quiri

ng a

lost

sig

nal c

ould

som

etim

es ta

ke h

ours

, or

not a

ccom

plis

hed

unt

il he

follo

win

g da

y. L

arge

mov

emen

ts s

uch

as s

witc

hing

da

y ro

osts

sep

arat

ed b

y 19

km

wer

e su

cces

sful

ly tr

acke

d, a

nd a

sin

gle

bat

cros

sing

2 P

uget

Sou

nd in

lets

(in

succ

essi

on) w

ere

succ

essf

ully

trac

ked.

Figu

re 5

. C

apito

l Lak

e, O

lym

pia,

Was

hing

ton.

One

of t

he d

ista

nt fe

edin

gar

eas

for t

he b

ats

from

th

e W

ooda

rd B

ay c

olon

y, w

here

som

e fo

rage

d co

ntin

uous

ly fo

r nea

rly 6

hou

rs b

efor

e re

turn

ing

to

a da

y ro

ost,

with

no

rest

bre

aks

or n

ight

roos

ting.

Res

ults

Thre

e of

the

10 ra

dio-

tagg

ed b

ats

fora

ged

for l

ong

perio

ds w

ith n

o ni

ght r

oost

ing

obse

rved

, 3 o

ther

s ni

ght r

oost

ed o

nly

whe

n it

star

ted

rain

ing

whi

le th

ey w

ere

invo

lved

in fe

edin

g, e

mer

ging

shor

tly a

fter t

he ra

in a

bate

d to

con

tinue

fora

ging

. The

rem

aini

ng 4

ro

utin

ely

roos

ted

2 o

r 3 ti

mes

nig

htly

, clo

se to

the

fora

ging

are

a (in

all

case

s a

lake

, lar

ge p

ond

or o

pen

wet

land

) for

bet

wee

n 5

and

40 m

inut

es, t

hen

emer

ging

to c

ontin

ue fo

ragi

ng in

the

adja

cent

are

as. A

ll ra

dio-

tagg

ed b

ats

wer

e tra

cked

to lo

catio

ns g

reat

er

than

8 k

m fr

om th

eir d

ay ro

ost,

7 ba

ts tr

avel

ed g

reat

er th

an 1

2 km

. Fi

ve o

f the

7 b

ats

tagg

ed a

t the

larg

e W

ooda

rd B

ay c

olon

y co

mm

uted

to a

250

acr

e ur

ban

lake

(Fig

. 5) a

dis

tanc

e ov

er 1

3 km

from

the

capt

ure

loca

tion.

Tw

o of

thes

e ba

ts w

ere

track

ed to

th

is d

ista

nt la

ke o

n 6

cons

ecut

ive

nigh

ts e

ach

(one

in J

uly

and

one

in A

ugus

t), a

nd o

ne o

f the

se tr

avel

ed d

irect

ly to

the

lake

from

th

e da

y ro

ost,

fora

ged

non-

stop

for 5

.75

hou

rs, t

hen

trave

led

back

to th

e ro

ost f

or a

tota

l of 6

.75

cont

inuo

us h

ours

"on

the

win

g."

Dis

cuss

ion

Thes

e on

e-w

ay c

omm

ute

dist

ance

s ra

ngin

g be

twee

n 10

and

15

km a

re c

onsi

dera

bly

grea

ter t

han

prev

ious

ly re

porte

d;

stud

ies

and

surv

eys

for t

hese

2 s

peci

es in

dica

te d

ista

nces

of <

1km

to 8

km

bet

wee

n da

y ro

osts

and

fora

ging

are

as (B

arbo

ur a

nd

Dav

is 1

969;

Bar

clay

, per

s. c

omm

.; H

enry

et a

l 200

2; J

ohns

ton

2002

). T

he n

on-s

top

flyin

g fo

r up

to 6

.75

hour

s w

as a

lso

unus

ual.

Chr

uszc

z &

Bar

clay

(200

3) fi

rst r

epor

ted

inse

ctiv

orou

s ba

ts (L

ong-

eare

d m

yotis

, Myo

tis e

votis

) spe

ndin

g 90

% o

f the

ir ou

t-of-r

oost

tim

e fo

ragi

ng. T

hey

felt

this

mig

ht b

e re

late

d to

the

spec

ies

bein

g ne

ar th

e ed

ge o

f its

rang

e, e

xerc

isin

g a

flexi

ble

feed

ing

stra

tegy

as

they

gle

an in

sect

s fro

m s

urfa

ces

as w

ell a

s ta

king

pre

y ae

rially

. Thi

s w

ould

allo

w th

em to

take

adv

anta

ge o

f the

per

iod

betw

een

mid

nigh

t and

sho

rtly

befo

re d

awn

whe

n ae

rial i

nsec

t cou

nts

are

low

er (A

ntho

ny e

t al.

1977

), bu

t ins

ects

on

surfa

ces

are

still

avai

labl

e fo

r gle

anin

g. H

owev

er, s

ince

Litt

le b

row

n an

d Yu

ma

bats

are

thou

ght t

o be

exc

lusi

vely

haw

king

(aer

ial)

feed

ers,

we

expe

ct th

at e

mer

gent

aqu

atic

inse

cts

are

avai

labl

e al

l nig

ht a

t Cap

itol L

ake

durin

g th

e su

mm

er m

onth

s. A

dditi

onal

ly, L

ittle

bro

wn

and

Yum

a ba

ts a

re c

omm

on in

this

regi

on a

nd n

ot n

ear t

he e

xten

t of t

heir

rang

e. T

hese

long

uni

nter

rupt

ed fo

ragi

ng ti

mes

ent

irely

over

this

one

lake

may

indi

cate

that

reso

urce

s at

the

site

are

not

all

that

abu

ndan

t, as

4.5

-5.

5 ho

urs

shou

ld b

e en

ough

tim

e fo

r a

Littl

e br

own

bat t

o fil

l its

sto

mac

h se

vera

l tim

es (B

arcl

ay, p

ers.

com

m).

The

thre

e ba

ts in

our

stu

dy th

at d

id n

ight

-roos

t reg

ular

ly

(incl

udin

g no

n-ra

iny

nigh

ts) d

id s

o fo

r onl

y 10

to 4

0 m

inut

es a

t a ti

me,

and

rare

ly m

ore

than

twic

e a

nigh

t. Th

ree

bats

wer

e ne

ver

obse

rved

nig

ht ro

ostin

g w

hen

away

from

the

day

roos

t. It

is u

nkno

wn

why

thes

e ba

ts w

ere

regu

larly

fora

ging

at g

reat

er d

ista

nces

than

pre

viou

sly

repo

rted

for L

ittle

bro

wn

or Y

uma

myo

tis. P

ossi

ble

expl

anat

ions

offe

red

have

incl

uded

: gre

ater

com

petit

ion

for

reso

urce

s by

a la

rger

col

ony;

bec

ause

the

dist

ant l

ake

offe

rs a

sup

erio

r for

age

oppo

rtuni

ties;

that

the

fine

scal

e m

onito

ring

ofin

divi

dual

bat

s re

veal

s be

havi

or th

at m

ight

be

been

mis

sed

by le

ss in

tens

ive

met

hods

.

13 k

m fr

om

Cap

itol L

ake

Ackn

owled

gem

ents

: Man

y tha

nks t

o Lor

i Salz

er, L

isa H

alloc

k, Mi

chae

l Bak

er, M

ary L

inder

s, Jo

anna

& JD

Mille

r, Jo

hn F

lecke

nstei

n, Jo

hn K

onov

sky,

Don M

artin

, Nan

cy La

ich, K

elly M

cAllis

ter, S

cott P

earso

n, Mi

chae

l Lac

ki, M

ichele

Zuc

kerb

erg,

Marg

aret

Gasp

ari, L

anny

Car

pente

r, Jo

hn C

alamb

okidi

s, Mi

chell

e Stev

ie, S

tephe

n and

Dak

ota P

asqu

al, R

ober

ta Da

venp

ort, T

yra Li

ndqu

ist, G

retch

en B

latz,

Jeff F

oisy,

Lee

Temp

leman

, Aim

ee H

art, P

at Or

msbe

e, an

d to t

he bo

ard o

f Cas

cadia

Rese

arch

. Rad

io tag

ging w

as m

ade p

ossib

le be

caus

e of s

uppo

rt fro

m Ba

ts No

rthwe

st, C

asca

dia R

esea

rch ,

and W

DF&W

Reg

ion 6.

Figu

re 1

. Fem

ale

and

juve

nile

bat

s ro

ost i

n la

rge

clus

ters

und

er th

e su

ppor

ting

beam

s of

the

aban

done

d ra

ilroa

d pi

er.

22 k

m

Conclusion

Our

resu

lts su

gges

t tha

t asp

ects

of th

e re

porte

d fo

ragi

ng b

ehav

ior f

or sm

all m

yotis

bats

is

not

app

licab

le th

is la

ndsc

ape,

and

that

thes

e sm

all b

ats h

ave

the

met

abol

ic c

apac

ity a

nd

endu

ranc

e to

regu

larly

mak

e lo

ng c

omm

utes

to fe

edin

g ar

eas.

Man

yfo

rage

long

hou

rs

inte

rrup

ted

by li

ttle

of n

o ni

ght r

oost

ing,

then

com

mut

e ba

ck to

a di

stan

t day

roos

t. T

he

hypo

thes

is m

ade

in 2

003

that

the

larg

e co

lony

size

at W

ooda

rd B

ay fo

rced

thes

e lo

ng

dist

ance

s in

orde

r to

disp

erse

ove

r a la

rger

feed

ing

area

was

not

supp

orte

d by

the

2004

dat

a ob

tain

ed fr

om “

MY

LU/Y

U”

bats

tagg

ed a

t Cap

itol L

ake

whi

ch c

omm

uted

just

as f

ar (u

p to

15

km) t

o sm

all m

ater

nity

roos

ts in

ent

irely

diff

eren

t are

as (F

igur

e 4)

. Whe

ther

the

beha

vior

of

thes

e ba

ts is

exc

eptio

nal o

r if t

he m

etho

ds e

mpl

oyed

faci

litat

edm

ore

rem

ote

obse

rvat

ions

that

m

ight

hav

e be

en o

ther

wis

e m

isse

d ca

nnot

be

infe

rred

from

this

smal

l stu

dy, b

ut tr

acki

ng b

ats

usin

g m

etho

ds th

at a

llow

con

tinuo

us o

bser

vatio

n of

the

subj

ect’s

beha

vior

may

hel

p us

de

velo

p m

etho

ds fo

r stu

dies

with

larg

er sa

mpl

ing

effo

rt. C

erta

inly

the

obse

rvat

ion

that

the

“sig

nal w

as lo

st”

shou

ld fl

ag th

e ne

ed to

reev

alua

te th

e as

sum

ptio

ns re

gard

ing

the

rang

e.

Trac

king

radi

o-ta

gged

bat

s in

an u

rban

land

scap

e of

fers

som

e un

ique

obs

tacl

es su

ch a

s lim

ited

publ

ic a

cces

s with

in th

e st

udy

area

, and

dec

reas

ed si

gnal

det

ectio

n ra

nge

due

to

incr

ease

d el

ectri

cal i

nter

fere

nce

(fro

m p

ower

line

s, co

mpu

ters

, and

stro

ng ra

dio

sign

als)

and

in

flat

are

as li

ke o

ur st

udy

area

, fro

m th

e la

ck o

f ele

vate

d va

ntag

e po

ints

to in

crea

se th

e lin

e-of

-sig

ht d

ista

nce.

And

bec

ause

of o

ur e

xper

ienc

e w

ith a

def

ectiv

e ta

g, w

e re

com

men

d pe

rfor

min

g di

stan

ce te

sts o

n al

l rad

io ta

gs p

rior t

o de

ploy

men

t on

stud

y su

bjec

ts. W

e co

ntin

ue

to in

vest

igat

e ba

t util

izat

ion

at C

apito

l Lak

e us

ing

tim

e ex

pans

ion

acou

stic

sam

plin

g m

etho

ds

to b

ette

r ide

ntify

the

spec

ies a

nd sp

atia

l dist

ribut

ion

at th

is la

rge

fora

ging

agg

rega

tion.

Figu

re 2

. Myo

tis lu

cifu

gus

with

.37

gram

radi

o ta

g, re

ady

for r

elea

se a

t ca

ptur

e si

te (i

n th

is c

ase

the

fora

ging

are

a).

17 k

m

19 k

m fr

om W

B R

oost

5 km

14 k

m

13 k

m

Larg

e M

ater

nity

Roo

stSm

all/M

ed. R

oost

Nig

ht R

oost

Non

-Woo

dard

Bay

M

yotis

For

agin

g Ar

eaW

ooda

rd B

ay M

yotis

Fo

ragi

ng A

rea

BA

T

KE

Y

Figu

re 4

. Map

of t

he a

rea

used

by

the

bats

und

er s

tudy

, enc

ompa

ssin

g ur

ban

Oly

mpi

a,

Was

hing

ton

and

the

area

nor

th a

nd e

ast o

f Oly

mpi

a bo

rder

ed o

n th

e no

rth b

y Pu

get S

ound

.