Bat Foraging Distance and Duration · Personal communication Brigham, RM, HDJN Aldridge, and RL...
Transcript of Bat Foraging Distance and Duration · Personal communication Brigham, RM, HDJN Aldridge, and RL...
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
.