Vanuatu Petrel - first live sighting?

I noticed a short note to the letter page of Birdwatch magazine (June 2008 issue) from Steve Wood (New Zealand) drawing attention to a gadfly petrel he'd photographed in March 2006 near the Kermadec Islands, New Zealand, that is suggestive of Vanuatu Petrel Pterodroma occulta. The photo is reproduced on the Wrybill Birding Tours web site. It is not clear if there is a series of photographs and whether the bird struck him as unusual (e.g. small) in the field.

This very poorly known seabird was first described by Imber and Tennyson in 2001. Six specimens were obtained by the American Museum of Natural History (AMNH) Whitney South Sea Expedition in January 1927, near the Banks Islands but until more recently, not recognized as different from the very similar White-necked Petrel P. cervicalis. In 1983, an additional specimen was taken in northern New South Wales, Australia.

They are significantly smaller than White-necked and show a more expansive area of gray on the underside of the primaries and a broader dark leading edge to the underwing. White-necked Petrels typically show a less dark underprimaries (e.g. photo (Fig. 15) by Chris Collins on OceanWanderers taken on the 2006 WPO recce). However, a number of seasoned field observers have commented that the presence of darker primaries is not unique to the smaller form, a point that is also made from analysis of specimens in the Imber and Tennyson paper. Indeed, check out this wonderful shot taken by B Whylie on a Wollongong pelagic in March 2008. One interesting but tangential point is the repeated occurrence of pairs of very similar looking seabirds (often found together at sea) that differ markedly in size (Tahiti/Beck's, Fea's/Zino, Greater/Lesser Snow Petrel). What's up with that?

Some authors (e.g. Michael Brooke 2004) treat Vanuatu and White-necked as conspecific, at least until more is known, but the split has been acknowledged in the new Australian Checklist (Christidis and Boles 2008). An alternative name in the literature is Falla's Petrel in honor of the renowned ornithologist Sir Robert Alexander Falla. Obviously, seabirders in Australia and New Zealand are looking carefully at 'White-necked/Vanuatu' Petrels and I imagine more information will emerge, especially from birders visiting the waters around the Vanuatu islands. A dedicated chumming expedition, mirroring Hadoram Shirihai's rediscovery of Beck's Petrel in the Bismark Archipelago off Papua New Guinea, may be highly rewarding. I've seen it rumored on the web that Hadoram has photographed candidate Vanuatu's Petrels but have no other information. Perhaps he can chime in here?

The location of Wood's new sighting seems puzzling. The Kermadec Islands (specifically Macauley Island) are the world stronghold for White-necked Petrel with 50,000 nesting pairs, and relatively distant from the locations of the Vanuatuan and Australian specimens. Onley and Scofield (2007) speculate that the birds might breed on Mera Lava (where the types were collected in 1927) and other islands in the northern part of the Vanuatu archipelago. Mere Lava (sometimes spelled Mera Lava) is a small volcanic island 52 km southeast of Gaua in the Banks Group (-14.4629°, 168.042°).

Literature Citations:

Christidis, L. and Walter E Boles (2008) Systematics and Taxonomy of Australian Birds. CSIRO Publishing.

Imber, M. J. and A.J.D. Tennyson (2001) A new petrel species (Procellariidae) from the south-west Pacific. Emu 101 (2): 123-127.

Wood, S. (2008) Another 'lost' petrel found? Birdwatch June 2008 Issue 192, p21.

UPDATE (25 May 2008): See Comments tab (below) for a response from Hadoram Shirihai.

Nesting ecology of Magenta Petrel (Taiko) - It's a man's world

A recent study by Hayley Lawrence and colleagues published in the Journal of Avian Biology (on-line ahead of print) describes the male-female ratio of the endangered Magenta Petrel Pterodroma magentae (aka Chatham Island Taiko). The world population is estimated at around 150 individuals with only 8-15 pairs known to have nested in recent years (Imber et al. 2005). Considerable effort is going into protecting and expanding the one known nesting colony located in dense scrub on the main Chatham Island (Rekohu/Wharekauri, decimal degrees -44.0705°, -176.634°). The new study summarizes genetic analysis of blood samples taken from fledglings and adults returning to the colony. As expected the sex ratio of chicks is close to parity, as of course are the pairs occupying burrows but the researchers find a striking dearth of females when they sample visiting adults. The males dig the nesting burrows and then attract females to them. The paucity of visiting females may help to explain the number of unpaired males. For examples, one male was at least 16 years old when he first bred. Conversely, most females are new breeders in the first season they are detected at burrows. The article does not specifically address the whereabouts of the 'missing females'. Have they perished before reaching breeding age (probably 7 years or longer) or is the density of territorial males too low to attract them to the colony where they can be sampled by researchers? A new colony at Sweetwaters south of the main Chathams settlement of Waitangi, that is being established within a fenced enclosure (to keep out introduced predators) will include an increased density of burrows and a slightly higher number of male chicks. Work on related petrel species such as Gray-faced Petrel (Pterodroma macroptera gouldi) has shown that males exhibit a stronger philopatric tendancy and will thus provide a stronger draw to passing females.

Hayley A. Lawrence, Craig D. Millar, Graeme A. Taylor, Linda D. Macdonald and David M. Lambert (2008) Excess of unpaired males in one of the World's most endangered seabirds, the Chatham Island taiko Pterodroma magentae. Journal of Avian Biology. On-line ahead of print.

M. J. Imber, G. A. Taylor, A. J. D. Tennyson, H. A. Aikman R. P. Scofield, J. Ballantyne, D. E. Crockett (2005) Non-breeding behaviour of Magenta Petrels Pterodroma magentae at Chatham Island, New Zealand. Ibis 147(4):758–763.

More updates from the 2008 Western Pacific Odyssey

Could this be the seabirding equivalent of the moonlandings? The world watching with baited breath? It's Day 21 of the 2008 Western Pacific Odyssey and the expedition has reached Chuuk an island group in the southwestern Pacific (7 deg, 0 min, 0 sec N, 152 deg , 0 min, 0 sec E) with many spectacular bird and marine mammal sightings under their belt. Photos of New Zealand Storm-Petrel, Polynesian Storm-Petrel and Beck's Petrel have been posted on the WildWings web site.

Click here for the latest from the 2008 WPO

2008 Western Pacific Odyssey gets off to a great start

Arguably the hottest ticket in the pelagic birding world is a berth aboard the Spirit of Enderby, operated by Heritage Expeditions (NZ) for its new Western Pacific Odyssey cruise. The month-long voyage begins in Auckland (-36.85°, 174.78°), traversing the Hauraki Gulf (-36.35°, 175.03°) before sailing for Norfolk Island (-29.03°, 167.95°) and New Caledonia (-21.5°, 165.5°). Landfalls are made in the Solomon Islands with a crossing of deep waters in the New Britain Trench. After landing at Truk (7.42°, 151.84°) in the Caroline group, the ship sails north to the Japanese Ogasawara Islands (27.08°, 142.19°) and docks in Yokohama (35.45°, 139.63°). In addition to numerous endemic landbirds, the cruise expects to log an amazing list of tropical Pacific sea birds and cetaceans, with special attention been given to much sought-after species such as Heinroth’s Shearwater, Polynesian Storm-Petrel and newly-rediscovered Beck’s Petrel. This is a MUST for world birders, seabird enthusiasts and travelers of any sort with a passion for remote places of the world.

In a recent posting to Seabird-News, John Brodie-Good relayed a message from leader Chris Collins with highlights of the first few days at sea, including at least 7 New Zealand Storm-Petrel and a fine assortment of pelagic gadfly petrels including Kermadec, Gould’s, White-necked, Black-winged and Grey-faced Petrels. Bristol (UK)-based offshore travel specialist WildWings has a very few places left for the 2009 voyage, some availability for 2010 and are now taking registrations for 2011! With such demand, one wonders how long before the first pelagic ticket scalper appears? Has anyone checked E-bay?