H. Shirihai et al. 75 Bull. B.O.C. 1995 115(2)
A new species of Puffinus shearwater from the
western Indian Ocean
by Hadoram Shirihai, Ian Sinclair & Peter R. Colston
Received 3 February 1995
A small Puffinus shearwater that was found alive on a beach at Durban on
the east coast of South Africa on 20 January 1987, but died shortly after,
was considered to be indeterminate in certain characters (Berruti 1990).
This specimen was presented to the Durban Museum where it was also
examined in detail by IS. In September 1994 it was sent on loan to The
Natural History Museum, formerly the British Museum (Natural
History) (BM (NH)), Tring, where PRC and HS were able to compare it
with a wide range of specimens of both Audubon's Shearwater P.
Iherminieri and Little Shearwater P. assimilis. While doing so, we located
a further specimen in the BM (NH) skin collection (see below) which
visual and x-ray study showed closely to match the Durban specimen in
plumage and structure as well as differing from all other specimens.
Besides the two specimens mentioned above, IS took photographs of
an apparent adult of this form captured on Durban beach in August
1981 (but prematurely released without measurements), and HS had
good views and took photographs of another individual at Eilat, Israel,
between 18 and 21 June 1992. There is also an earlier observation by IS
of a similar bird watched close inshore for an extended period at
Richard's Bay, South Africa (28?47'S, 32?05'E) on 20 February 1976
(Shirihai & Sinclair 1994). We are convinced that we are not dealing
with aberrant individuals since what is apparently this form has been
found to be locally abundant in the western Indian Ocean (Shirihai &
Sinclair 1994). Between January 1990 and January 1993, IS observed
many such individuals seemingly identical to the above mentioned
specimens. These birds occurred both south and north of the Comoro
Islands, west and south of Aldabra (Seychelles), in the Mozambique
Channel (including around the Bassas da India atoll), and east of
Maputo, Mozambique (see Table 1). In these areas, they were easily
recognised at sea by their larger size (compared with Little
Shearwater), and very black-and-white appearance with white undertail
coverts, reminiscent of Manx Shearwater P. puffinus, but smaller and
with much quicker wing-beats.
We appreciate that the taxonomy of the small and medium-sized
shearwaters is still full of uncertainties; but this distinctive form
cannot, on present evidence, be assigned to and treated as a subspecies
of any known form. We therefore consider that it should be treated as a
new species, for which we propose the name
Puffinus atrodorsalis sp. nov.
Holotype. Adult, unsexed, found alive on the beach, Durban, South
Africa (29?53'S, 31?00'E), 20 January 1987 (died shortly after).