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
288
Bull.
B.O.C.
2010
130(4)
the
new
form's
breeding
island.
We
compare
our
findings
to
P.
brevipes
observed
at
sea
off
Gau
Island,
Fiji
(cf.
Shirihai
et
al.
2009).
Murphy
(1929),
Bourne
(1983)
and
Imber
(1985)
tackled
the
complexity
posed
by
the
subgenus
(or
superspecies)
Cookilaria.
All
recent
authors
have
chosen
to
treat
P.
brevipes
and
Gould's
Petrel
P.
leucoptera
as
separate
species
(e.g.,
Watling
1986,
Brooke
2004).
Furthermore,
Imber
&
Jenkins
(1981)
validated
New
Caledonian
Petrel
P.
I.
caledonica
de
Naurois,
1978,
as
a
race
of
Gould's
Petrel
from
New
Caledonia,
distinct
from
nominate
P.
I.
leucoptera
which
breeds
on
Cabbage
Tree
Island,
New
South
Wales,
Australia.
Since
Murphy
(1929)
and
Bourne
(1983)
no
one
has
inferred
that
P.
brevipes
remains
poorly
known
taxonomically,
although
Imber
(1985)
questioned
whether
more
than
one
subspecies
might
be
involved.
Other
than
the
pioneering
work
on
P.
brevipes
by
Watling
(1986),
no
one
has
extensively
examined
the
variation
presented
by
this
taxon.
Despite
that
the
holotype's
provenance
is
doubtful
(Murphy
1929),
the
type
and
co-type
are
indeed
assignable
to
P.
brevipes
(pers.
obs.).
Our
familiarity
with
all
populations
assigned
to
P.
brevipes
and
P.
leucoptera
known
to
date,
involving
specimens
in
some
of
the
world's
major
museums
and
live
individuals
in
or
around
all
of
the
breeding
islands,
has
yielded
the
discovery
of
a
new
taxon
of
P.
brevipes.
The
morphometric
differences
found
in
six
of
the
seven
AMNH
specimens
(see
below
for
AMNH
216923,
which
we
consider
separately)
were
augmented
by
study
of
plumage
variation
at
sea,
and
by
the
apparently
distinctive
pelagic
feeding
behaviour.
For
our
purposes
here,
we
will
focus
mostly
on
standard
morphological
differences
from
all
other
populations
of
P.
brevipes.
Given
that
this
work
remains
in
progress
(a
thorough
genetic
analysis
is
currently
ongoing),
and
the
lack
of
any
comparative
acoustic
studies,
we
conservatively
assign
the
new
taxon
subspecies
rank,
under
the
following
name:
Pterodroma
brevipes
magnificens
subsp.
nov.
Magnificent
Petrel
Holotype.
See
Fig.
2.
American
Museum
of
Natural
History,
New
York
(AMNH
216919).
Male
collected
on
28
January
1927
by
R.
H.
Beck
at
sea
east
of
Mera
Lava,
Banks
Islands,
north
Vanuatu.
Precise
locality
unknown,
but
based
on
the
original
label,
the
AMNH
catalogue,
and
the
Whitney
South
Sea
Expedition
diary
by
Frederick
P.
Drowne,
this
is
c.30
nautical
miles
east
of
Mera
Lava
(cf.
Imber
&
Tennyson
2001).
We
are
uncertain
of
the
age
of
the
holotype:
all
feather
tracts
are
apparently
of
the
same
generation,
suggesting
a
recently
fledged
bird,
but
many
of
the
larger
upperwing-coverts,
tertials
and
scapulars
are
already
worn
and
bleached
browner,
suggesting
an
adult.
The
bill
is
uniform
black
(without
obvious
horn-coloured
markings
characteristic
of
older
individuals),
which
might
also
support
the
notion
that
it
is
juvenile,
but
in
contrast
the
primary
tips
are
round
(not
pointed)
suggesting
an
adult.
Finally,
Beck
labelled
it
as
a
male
at
'nesting'
stage,
suggesting
enlarged
gonads,
but
Murphy
who
examined
the
specimens
not
long
after
they
were
skinned
concluded
that
these
were
juveniles
in
slightly
worn
plumage
(Murphy
unpubl.
MS
at
AMNH).
Measurements
of
the
holotype.
Wing
length
208.0
mm;
tail
length
97.0
mm;
oilmen
(bill
length
from
feathers)
23.0
mm;
bill
depth
(at
top
of
maxillary
unguis
to
base
of
mandibular
unguis)
8.0
mm;
tarsus
length
27.8
mm.
Paratypes.—See
Fig.
2
and
Table
1^
(for
mean
values).
.AMNH
215400
(female),
216921
(male),
216920
(male)
and
222193
(female),
all
collected
by
R.
H.
Beck
at
sea
at
the
same
locality
as
the
holotype,
on
28/29
January
1927.
Measurements
(by
HS)
as
follows:
AMNH
215400:
wing
212.0
mm;
tail
99.0
mm;
oilmen
(to
feathers)
21.5
mm;
bill
depth
(top
of