A
fe al
cat
with
a
tipped
ea ,
i dicati g
it
was
eute ed
i
a
t ap- eute – etu
p og am.
Images
C edit:
B ocke
I aglo y/Wikipedia
Asce sio
Isla d
offe s
a
st iki g
example
of
how
quickly
a
i t oduced
p edato
ca
eshape
a
isla d’s
wildlife.
Cats
b ought
to
the
South
Atla tic
isla d
i
1815
p eyed
heavily
o
seabi ds,
d ivi g
almost
all
species
away
f om
the
mai
isla d
a d
leavi g
su vivi g
colo ies
i
places
cats
could
ot
each.
Mo e
tha
a
ce tu y
late ,
co se vatio ists
bega
a
majo
effo t
to
emove
the
fe al
cats
while
p otecti g
the
isla d’s
domestic
a imals
a d
people.The
campaig
succeeded,
a d
the
last
fe al
cat
was
killed
i
Ja ua y
2004.
I
the
yea s
that
followed,
seabi ds
bega
etu i g
to
pa ts
of
the
mai la d
whe e
they
had
p eviously
bee
u able
to
b eed
safely.
The
study
published
i
‘O yx’
(The
I te atio al
Jou al
of
Co se vatio ,
Camb idge
U ive sity
P ess)
docume ts
both
the
difficult
e adicatio
campaig
a d
the
ea ly
sig s
of
ecove y,
showi g
how
emovi g
o e
i vasive
p edato
ca
eope
habitat
fo
wildlife.
How
did
cats
cha ge
Asce sio
isla d’s
seabi d
colo ies
Asce sio
Isla d
is
a
97-squa e-kilomet e
isla d
i
the
t opical
South
Atla tic.
Although
much
of
its
la dscape
is
ugged
a d
ba e ,
it
has
lo g
bee
a
impo ta t
home
fo
seabi ds,
i cludi g
the
e demic
‘Asce sio
f igatebi d’
a d
a
disti ct
fo m
of
masked
booby.Befo e
cats
a ived,
the
isla d
suppo ted
huge
seabi d
colo ies.
Thei
i t oductio
i
1815
cha ged
that
d amatically.
Acco di g
to
the
study,
cats
p eyed
so
heavily
o
seabi ds
that
all
but
the
‘sooty
te ’
disappea ed
f om
the
mai
isla d.
The
su vivi g
bi ds
we e
la gely
pushed
i to
cliff
ledges,
offsho e
stacks
a d
small
isla ds
that
cats
could
ot
each.
Eve
sooty
te s
we e
still
heavily
ta geted
whe
they
attempted
to
oost
o
b eed
o
the
mai la d.
Juve ile
Asce sio
F igatebi d.
Image
C edit:
D ew
Ave y/Wikipedia
Why
was
emovi g
the
fe al
cats
such
a
difficult
task
Removi g
fe al
cats
f om
a
u i habited
isla d
would
al eady
be
a
dema di g
co se vatio
p oject.
Asce sio
p ese ted
a
additio al
challe ge
because
a ou d
900
people
lived
the e,
while
domestic
cats
also
eeded
to
be
p otected.
The
esea che s
explai ed
that
the
campaig
had
to
elimi ate
fe al
cats
without
c eati g
u acceptable
isks
to
people
o
pets.
Six
mo ths
befo e
the
e adicatio
bega ,
co se vatio ists
sta ted
public
meeti gs,
ewspape
a ticles,
email
updates
a d
co sultatio s
with
local
o ga isatio s.Domestic
cats
we e
equi ed
to
be
egiste ed,
mic ochipped
a d
eute ed.
Ow e s
we e
also
give
eflective
colla s
so
that
pets
could
be
ide tified
du i g
the
ope atio .
Local
people
we e
t ai ed
a d
employed
fo
mo ito i g
wo k,
helpi g
to
build
wide
commu ity
i volveme t
i
the
p oject.
How
we e
the
fe al
cats
emoved
The
e adicatio
p og amme
bega
i
Feb ua y
2002
a d
used
a
combi atio
of
poiso ed
bait
a d
live
t appi g.
A eas
a ou d
settleme ts
we e
t eated
diffe e tly
because
of
the
p ese ce
of
people
a d
domestic
a imals.
A
o e-kilomet e
buffe
a ou d
each
settleme t
was
kept
f ee
of
poiso
bait.
I stead,
la ge
umbe s
of
‘cage
t aps’
we e
used
the e.
Outside
those
a eas,
poiso ed
fish
bait
was
deployed
ac oss
the
isla d.The
ope atio
took
place
i
stages.
The
fi st,
k ow
as
the
‘k ock-dow ’
phase,
aimed
to
emove
most
of
the
fe al
cats
quickly.
It
was
followed
by
a
‘mop-up’
phase,
du i g
which
wo ke s
sea ched
fo
sig s
of
cats
a d
ta geted
the
emai i g
a imals.
Fi ally,
a
two-yea
co fi matio
phase
used
hu d eds
of
t acki g
pits
to
make
su e
o
b eedi g
fe al
cats
emai ed.
The
scale
of
the
effo t
was
substa tial.
The
p oject
used
mo e
tha
42,000
cage-t aps,
while
75,902
poiso ed
baits
we e
laid.
The
last
fe al
cat
was
killed
o
31
Ja ua y
2004.
Subseque t
mo ito i g
p oduced
o
evide ce
of
a
emai i g
ep oduci g
fe al
populatio .
Did
the
seabi ds
actually
etu
afte
the
cats
disappea ed
The
a swe
was
yes,
although
the
ecove y
was
g adual.
The
study
fou d
that
‘5
seabi d
species’
ecolo ised
pa ts
of
the
mai la d
afte
the
e adicatio
p og amme.
Thei
umbe s
i c eased
ove
the
study
pe iod,
with
ew
colo ies
appea i g
i
mai la d
a eas
close
to
existi g
colo ies.The
etu
was
especially
sig ifica t
because
these
a eas
had
p eviously
bee
accessible
to
cats.
Befo e
e adicatio ,
seabi ds
attempti g
to
establish
themselves
the e
faced
a
se ious
isk
of
bei g
killed.
O ce
that
th eat
disappea ed,
bi ds
f om
established
colo ies
could
begi
expa di g
i to
p eviously
u safe
habitats.
The
cha ge
was
also
visible
i
deaths
of
adult
sooty
te s.
The
study
epo ts
that
the
umbe
of
adult
sooty
te s
fou d
dead
i
thei
colo ies
fell
f om
mo e
tha
4,500
a
yea
to
egligible
levels
afte
cats
we e
emoved.
This
suggested
that
adult
su vival
had
imp oved
co side ably.
Sooty
te .
Image
C edit:
Ma i ha
do
B asil/Wikipedia
Why
did
the
seabi ds
ot
ecove
immediately
Removi g
the
cats
solved
o e
majo
p oblem,
but
it
did
ot
i sta tly
esto e
the
isla d’s
seabi d
populatio .
Resea che s
fou d
that
b eedi g
success
fo
seve al
species
was
elatively
low
compa ed
with
populatio s
elsewhe e.
They
suggested
seve al
possible
expla atio s.
Food
availability
a ou d
Asce sio
could
have
limited
b eedi g
success.
Ma y
bi ds
a ivi g
to
establish
ew
mai la d
colo ies
we e
also
likely
to
be
i expe ie ced
b eede s.
I
additio ,
black
ats
we e
obse ved
eati g
seabi d
eggs
a d
chicks
afte
the
cats
had
disappea ed.The
esea che s
st essed
that
fu the
wo k
would
be
eeded
to
dete mi e
how
much
each
facto
affected
the
bi ds.
Impo ta tly,
the
study
did
ot
suggest
that
the
ats
had
simply
i c eased
because
the
cats
we e
go e.
I stead,
at
umbe s
appea ed
to
fluctuate
with
ai fall,
vegetatio
g owth
a d
food
availability.
What
does
Asce sio
Isla d’s
ecove y
show
The
Asce sio
Isla d
p oject
demo st ates
that
emovi g
a
i vasive
p edato
ca
allow
wildlife
to
eclaim
habitat
that
had
effectively
bee
lost.
The
ecove y
was
ot
immediate
o
complete.
The
ew
seabi d
colo ies
bega
with
o ly
a
few
i dividuals,
a d
seabi d
colo ies
ca
take
time
to
g ow.
The
esea che s
oted
that
futu e
g owth
was
likely
to
depe d
heavily
o
co ti ued
immig atio ,
while
ep oductio
withi
the
ew
colo ies
could
emai
slow
because
b eedi g
success
was
elatively
poo .The
p oject
also
showed
that
co se vatio
o
i habited
isla ds
equi es
mo e
tha
simply
emovi g
a
i vasive
species.
Public
commu icatio ,
ca eful
pla i g
a d
p otectio
of
domestic
a imals
we e
all
impo ta t
pa ts
of
the
ope atio .
Fo
Asce sio
Isla d,
the
disappea a ce
of
fe al
cats
did
ot
i sta tly
etu
the
isla d
to
its
fo me
state.
But
it
emoved
a
majo
obstacle.
Seabi ds
that
had
bee
fo ced
i to
p edato -f ee
efuges
fo
ge e atio s
bega
movi g
back
o to
the
mai la d,
p ovidi g
a
ea ly
sig
that
damaged
isla d
ecosystems
ca
begi
to
ecove
whe
the
p essu e
espo sible
fo
thei
decli e
is
emoved.