Bulletin of The British Ornithologists' Club 2010 130(4):286-301
47499910

A new taxon of Collared Petrel Pterodroma brevipes from the Banks Islands, Vanuatu

Vincent Bretagnolle, Hadoram Shirihai
Vincent
Bretagnolle
&
Hadoram
Shirihai
286
Bull.
B.O.C.
2010
130(4)
A
new
taxon
of
Collared
Petrel
Pterodroma
brevipes
from
the
Banks
Islands,
Vanuatu
by
Vincent
Bretagnolle
&
Hadoram
Shirihai
Received
12
September
2010
Summary.
A
new
taxon
of
all-dark
and
small-sized
Collared
Petrel
Pterodroma
brevipes
is
described
from
northern
Vanuatu.
The
description
is
based
on
six
specimens
held
at
the
American
Museum
of
Natural
History
collected
in
1927
east
of
Mera
Lava,
in
the
Banks
Islands.
We
recently
discovered
the
new
taxon
to
be
rather
abundant
around
the
Banks
Islands,
apparently
located
its
breeding
grounds,
and
described
its
unique
feeding
behaviour.
The
new
taxon
differs
from
other
populations
of
P.
brevipes,
which
mostly
breed
elsewhere
in
Vanuatu
and
in
Fiji,
in
its
combination
of
smaller
size,
with
shorter
wings
but
relatively
longer
tail,
and
shorter
bill
and
tarsus.
More
importantly,
unlike
any
other
populations
of
P.
brevipes
which
all
are
polymorphic,
present
evidence
suggests
that
the
new
taxon
occurs
solely
in
a
monomorphic
dark
form.
The
new
taxon
is
at
least
as
distinctive
as
many
other
recognised
races
and
even
species
of
petrels.
Subspecies
rank
is
allocated
tentatively;
with
future
study,
the
new
taxon
might
merit
species
status.
Mostly
due
to
predation
by
alien
mammals
at
the
breeding
sites
or
direct
harvesting
by
Man,
many
petrel
taxa
are
globally
threatened
(www.birdlife.org/datazone).
Some
were
even
thought
to
be
extinct
but
have
been
recently
rediscovered,
e.g.,
Zino's
Petrel
Pterodroma
madeira
(Zino
&
Zino
1986),
Magenta
Petrel
P.
magentae
(Crockett
1979,
1994),
Vanuatu
Petrel
P.
(cervicalis)
occulta
(Totterman
2009,
Shirihai
&
Bretagnolle
2010),
Mascarene
Petrel
Pseudobulweria
aterrima
(Jouanin
1970,
Bretagnolle
et
al.
1998),
Beck's
Petrel
P.
becki
(Shirihai
2008)
and
New
Zealand
Storm
Petrel
Oceanites
(Pealeornis)
maoriana
(Saville
et.
al.
2003).
The
increase
in
pelagic
trips
specifically
designed
to
search
for
rare
petrels
never
before
seen
at
sea
has
also
yielded
the
first
documented
at-sea
records
of
Zino's
Petrel
Pterodroma
madeira
(Shirihai
2009)
and
Fiji
Petrel
Pseudobulweria
macgiUivrayi
(Shirihai
et
al.
2009).
In
addition
to
rediscoveries,
previously
unrecognised
petrel
taxa
may
have
been
overlooked
due
to
a
combination
of
lack
of
knowledge
and
their
remote
ranges,
one
example
being
the
still
unresolved
case
involving
the
Black-capped
Petrel
Pterodroma
hasitata
complex
of
the
Caribbean
(Howell
&
Patterson
2008,
Shirihai
et
al.
2010a).
We
first
became
aware
of
the
existence
of
a
new
form
of
Collared
Petrel
Pterodroma
brevipes
in
northern
Vanuatu
in
1997,
while
studying
specimens
in
the
American
Museum
of
Natural
History,
New
York
(AMNH),
when
VB
found
six
dark-coloured
specimens,
collected
at
sea,
by
Rollo
Beck
during
the
Whitney
South
Sea
Expedition
in
January
1927.
These
specimens
were
collected
exactly
at
the
same
location
(east
of
Mera
Lava;
Fig.
14)
and
at
the
same
time
as
the
P.
occulta
specimens
that
were
suggested
to
represent
a
new
species
of
petrel
(Imber
&
Tennyson
1981).
Then,
during
pelagic
work
in
Melanesian
waters
post-2003,
especially
in
January-March
2006
and
2007,
HS
photographed
obviously
different
petrels
on
several
occasions,
including
four
extremely
dark
brevipes
over
the
Torres
Rise,
c.150
km
west
of
the
Bank
Islands
(14°39'S,
165°16'E)
on
16
February
2007.
These
observations
led
to
new
research
into
their
identity:
further
visits
were
made
to
AMNH
(in
August
2008
and
March
2010
by
HS),
and
a
special
expedition
was
made
to
the
Banks
group
in
December
2009
(HS
&
VB)
where
we
conducted
observations
on
P.
brevipes,
and
apparently
discovered