The recent Zegrahm Expeditions New Zealand to New Guinea program provided a cornucopia of rare and little known seabird species. It all began with wonderful sightings and photographic opportunities of the recently rediscovered New Zealand storm-petrel and ended with a Beck’s petrel, the fifth of the voyage, as the expedition vessel, the Clipper Odyssey approached the Laughlan Islands in Papua New Guinea. Along the way there were also such species as Heinroth’s and tropical shearwaters, collared, black-winged, Tahiti and white-necked petrels.
The most significant sightings and photographs, however, were of Vanuatu petrels, a species that has not been seen at sea for over 80 years and never before photographed over the ocean. Previously known only from seven museum skins, this rare and virtually unknown seabird has now only been seen twice, since it was originally collected in January of 1927. The Zegrahm team, led by seabird expert Peter Harrison, observed this rare species in the northern Vanuatu Islands just 60 miles from where the original type specimen was collected by Rollo Beck during the Whitney South Seas Expedition.
The sightings of this long-lost seabird species occurred during our northward voyage from Auckland, New Zealand to Port Moresby, Papua New Guinea. The expedition visited several remote and seldom visited island groups in their quest for seabirds, including New Caledonia, the Vanuatu archipelago and the Solomon Islands. Twenty-one individual Vanuatu petrels were seen over a three-day period. Sightings of this “back-from-the-dead” species culminated on February 8 when 11 birds were observed in a one-hour period. Of special significance is that nine of these birds were sitting, rafting on the sea just before dusk in front of several off-shore rock stacks. These islets may indicate a possible breeding haven for this enigmatic species.
In addition to the six specimens collected at sea in 1927 off the island of Mera Lava, Banks Islands, northern Vanuatu, one other specimen was found dead in 1983, on a roadside in New South Wales, Australia. In February of 2009 a small number of Vanuatu petrels were discovered breeding in the mountains of Vanua Lava. The 2010 sightings, therefore, of 21 individual Vanuatu Petrels, at sea, in the same geographic area and at virtually the same time of year as the original 1927 sightings, are noteworthy. They constitute only the second documented sightings of this poorly known species since originally collected over 80 years ago and confirm that the species is still extant.
The six original specimens obtained by the American Museum of Natural History (AMNH) Whitney South Sea Expedition in 1927 lay unnoticed and not recognized as different from the very similar White-necked petrel for almost 50 years. It was not until 1976 that the New Zealand ornithologist, R. A. Falla, recognized them as a smaller, distinct form. They were only described as a full species by M. J. Imber and A. J. D. Tennyson in 2001 (Emu 2001, 101, 123-127).
The identification of Vanuatu petrel at sea is complicated by its close resemblance to the white-necked petrel, Pterodroma cervicalis. The Vanuatu petrel, however, is smaller than white-necked petrel, with a distinctly narrower, longer-tailed jizz. It also shows a more expansive area of dark grey to black on the underside of the primaries and a broader, dark leading edge to the outer underwing between the carpal and wingtip. The identification process is hampered, however, as a small percentage of white-necked petrels, around eight to ten percent, can also show darker tips to the underside of the primaries and a darker leading edge. In this instance, all 21 sightings of Vanuatu petrels showed consistent, solid dark wing-tips and a dark, broad leading edge to the underwing. Hurrah!