Alaska
ca ibou
A
he d
of
just
25
ca ibou
calves
eleased
o
a
emote
Alaska
isla d
i
1958
to
p ovide
eme ge cy
meat
fo
US
milita y
pe so el
eve tually
g ew
to
2,750
a imals
by
2005.
The
apid
g owth
placed
heavy
p essu e
o
the
f agile
ecosystem
of
the
Aleutia
Isla ds.
The
sto y
of
the
he d
has
si ce
become
a
example
of
how
i t oduci g
a imals
fo
a
sho t-te m
pu pose
ca
c eate
se ious
e vi o me tal
p oblems
whe
co ditio s
cha ge.
The
populatio
histo y
has
bee
docume ted
i
wildlife
ma ageme t
epo ts
f om
the
Alaska
Depa tme t
of
Fish
a d
Game
(ADF&G),
alo g
with
studies
by
the
US
Fish
a d
Wildlife
Se vice
a d
the
US
Geological
Su vey
(USGS).
Histo ical
eco ds
show
that
the
o igi al
t a spla t
was
a
joi t
p oject
i volvi g
the
US
Navy,
Ai
Fo ce,
Ma i es
a d
wildlife
expe ts.
Du i g
the
Cold
Wa ,
milita y
pla e s
we e
co ce ed
that
emote
bases
could
be
cut
off
f om
o mal
supply
outes.
To
p epa e
fo
such
a
situatio ,
officials
decided
to
c eate
a
self-sustai i g
sou ce
of
meat
o
Adak
Isla d,
i
the
ce t al
Aleutia
Isla ds.
A
Cold
Wa
food
ese ve
The
ca ibou
calves
came
f om
the
Nelchi a
he d
o
mai la d
Alaska.
I
1958,
they
we e
flow
to
U alga
Bight
o
Adak
Isla d.
Ma i e
pe so el
ca ed
fo
the
you g
a imals
afte
thei
a ival.
They
bottle-fed
them
a d
p ovided
beddi g
u til
the
calves
we e
st o g
e ough
to
fi d
food
o
thei
ow .
The
pla
had
two
pu poses.
The
mai
goal
was
to
c eate
a
eme ge cy
food
supply
fo
milita y
pe so el
statio ed
at
Naval
Ai
Statio
Adak.
The
a imals
would
also
p ovide
hu ti g
oppo tu ities
fo
se viceme
du i g
thei
f ee
time.
The
isla d
tu ed
out
to
be
a
u usually
good
e vi o me t
fo
the
ca ibou.
Adak
had
o
wolves
o
bea s
to
hu t
them.
Its
ma itime
climate
was
elatively
mild,
a d
the
isla d
did
ot
have
the
la ge
umbe s
of
biti g
i sects
fou d
i
ma y
pa ts
of
mai la d
Alaska.
The
ca ibou
also
had
ple ty
of
liche s
a d
mosses
to
eat.
Hu ti g
kept
the
he d
u de
co t ol
Fo
seve al
decades,
the
populatio
emai ed
elatively
stable.
F om
1958
u til
the
ea ly
1990s,
milita y
pe so el
egula ly
hu ted
the
ca ibou.
This
hu ti g
effectively
took
the
place
of
the
atu al
p edatio
that
would
o mally
help
co t ol
a
he d.
ADF&G
eco ds
i dicate
that
hu ti g
kept
the
populatio
at
a ou d
300
to
600
a imals
fo
mo e
tha
30
yea s.
Du i g
this
pe iod,
esea che s
fou d
that
the
Adak
ca ibou
we e
doi g
pa ticula ly
well.
They
g ew
la ge ,
p oduced
mo e
calves
a d
bega
ep oduci g
at
you ge
ages
tha
the
o igi al
he d
o
mai la d
Alaska.
The
system
wo ked
because
the
umbe
of
a imals
emoved
th ough
hu ti g
helped
bala ce
thei
high
su vival
a d
ep oductio
ates.
But
that
bala ce
depe ded
heavily
o
the
p ese ce
of
the
milita y.
The
milita y
leaves
a d
the
populatio
explodes
Eve ythi g
cha ged
i
1994,
whe
the
US
Depa tme t
of
Defe se
closed
Naval
Ai
Statio
Adak.
The
closu e
g eatly
educed
the
umbe
of
people
livi g
o
the
isla d.
With
fa
fewe
milita y
pe so el
a ou d,
hu ti g
d opped
sha ply.
The
ca ibou
we e
sudde ly
faci g
almost
o
hu ti g
a d
had
o
atu al
p edato s.
Thei
umbe s
bega
to
ise
apidly.
By
2005,
a
ae ial
a d
g ou d
su vey
by
ADF&G
a d
the
US
Fish
a d
Wildlife
Se vice
cou ted
about
2,750
ca ibou
o
Adak.
Late
su veys
showed
that
the
populatio
emai ed
high.
A
joi t
ce sus
i
2012
estimated
that
betwee
2,500
a d
2,800
a imals
we e
still
livi g
o
the
isla d.
The
he d
had
go e
f om
bei g
a
ca efully
ma aged
milita y
food
ese ve
to
a
majo
ecological
p oblem.
Ove g azi g
damages
the
isla d
The
g owi g
populatio
placed
i c easi g
p essu e
o
Adak’s
limited
vegetatio .
Wildlife
expe ts
docume ted
se ious
damage,
pa ticula ly
i
the
southe
pa ts
of
the
isla d.
The
ca ibou
ate
la ge
amou ts
of
ative
vegetatio ,
i cludi g
slow-g owi g
liche s.
Liche
ca
take
ma y
yea s,
sometimes
decades,
to
ecove
afte
heavy
g azi g.
O ce
the
vegetatio
was
emoved,
the
a imals
also
damaged
the
soil
by
c eati g
la ge
umbe s
of
t ails.
These
t ails
co t ibuted
to
e osio
alo g
coastal
idges
a d
a ou d
lakes
a d
othe
low-lyi g
a eas.
The
p oblem
became
mo e
se ious
as
the
he d
g ew.
With
less
food
available
i
some
a eas,
the
ca ibou
bega
looki g
fo
ew
places
to
feed.
This
eve tually
led
them
beyo d
Adak
Isla d.
Ca ibou
begi
movi g
to
othe
isla ds
Adak
is
sepa ated
f om
ea by
Kagalaska
Isla d
by
a
elatively
a ow
st etch
of
wate .
As
the
he d
expa ded,
some
ca ibou
ma aged
to
c oss
the
cha el.
USGS
esea che s
late
fou d
evide ce
that
ca ibou
had
established
a
p ese ce
o
Kagalaska.
Field
su veys
betwee
2010
a d
2015
eco ded
both
ca ibou
sig s
a d
live
a imals
o
the
eighbou i g
isla d.
Wildlife
ma age s
became
co ce ed
that
the
a imals
could
establish
a
pe ma e t
b eedi g
populatio
the e
a d
eve tually
sp ead
to
othe
isla ds
i
the
Aleutia
chai .
I
2015,
efuge
ma age s
bega
ta geted
effo ts
to
co t ol
the
a imals
o
Kagalaska
a d
p eve t
fu the
expa sio .
A
difficult
p oblem
to
ma age
Co t olli g
the
Adak
he d
emai s
difficult.
The
isla d
is
ext emely
emote,
lyi g
almost
1,200
miles
southwest
of
A cho age.
B i gi g
hu te s
o
p ofessio al
teams
to
the
a ea
ca
be
expe sive
a d
logistically
challe gi g.
Afte
the
milita y
base
closed,
hu ti g
ules
we e
cha ged
to
allow
la ge
ha vests.
Howeve ,
the
umbe
of
a imals
emoved
th ough
hu ti g
has
ot
always
bee
e ough
to
keep
pace
with
the
he d’s
atu al
g owth.
The
isla d’s
isolatio
makes
la ge-scale
co t ol
ope atio s
pa ticula ly
complicated.
The
Adak
ca ibou
sto y
also
shows
how
st o gly
a
ecosystem
ca
depe d
o
huma
activity.
While
milita y
hu ti g
was
taki g
place,
the
populatio
emai ed
withi
a
elatively
ma ageable
a ge.
O ce
that
hu ti g
stopped,
the
same
a imals
apidly
multiplied
because
the e
we e
o
wolves,
bea s
o
othe
majo
p edato s
to
co t ol
them.
A
lesso
i
u i te ded
co seque ces
The
ca ibou
we e
i t oduced
to
Adak
fo
a
p actical
easo .
Du i g
the
Cold
Wa ,
milita y
pla e s
wa ted
a
eliable
sou ce
of
food
i
case
supply
li es
to
the
emote
base
we e
i te upted.
At
fi st,
the
pla
appea ed
to
wo k.
The
he d
su vived,
ep oduced
a d
p ovided
both
eme ge cy
food
a d
hu ti g
oppo tu ities.
But
the
co ditio s
that
allowed
the
he d
to
th ive
also
c eated
the
p oblem.
The
abse ce
of
atu al
p edato s,
ple tiful
vegetatio
a d
a
mild
climate
allowed
the
populatio
to
g ow
apidly
o ce
huma
hu ti g
decli ed.
The
esulti g
ove g azi g
damaged
f agile
isla d
habitats
a d
eve tually
pushed
some
a imals
towa ds
eighbou i g
isla ds.
The
Adak
he d
is
ow
a
well-k ow
example
of
the
isks
i volved
i
i t oduci g
a imals
to
isolated
e vi o me ts.
It
demo st ates
that
a
species
i t oduced
fo
a
specific
huma
eed
ca
become
difficult
to
co t ol
whe
the
ci cumsta ces
that
o igi ally
kept
its
populatio
i
check
disappea .
What
bega
as
a
Cold
Wa
pla
to
p otect
milita y
food
supplies
ultimately
became
a
lo g-te m
wildlife
ma ageme t
challe ge
fo
Alaska.