Tahiti Petrel Pseudobulweria rostrata Scientific name definitions

Despite its name, the Tahiti Petrel has been recorded from such far-flung localities as Oman, South Africa and the United States, perfectly illustrating the endlessly astonishing dispersal capacities of most of the truly pelagic seabirds. Of course, these records represent rather extraordinary acts of vagrancy, the species’ regular range instead being limited to the equatorial Pacific, with breeding outposts in Fiji, American Samoa, the Society Islands, Marquesas Islands, Gambier Islands, Vanuatu and New Caledonia, and possibly also on Rarotonga (in the Cook Islands), although to date just one egg has been found and the Tahiti Petrel’s breeding ecology is to all intents and purposes unknown. This is a largely dark, large- and bulbous-billed gadfly petrel with a white abdomen and wedge-shaped tail, elongated body, and a long neck but relatively small head. Two races are recognized, although trouessarti differs from the nominate only in its, on average, slightly larger bill. Another Pacific seabird, the even rarer and more poorly known Beck’s Petrel (Pseudobulweria becki) is identical in plumage to the present species, but is considerably smaller with a proportionately more slender bill, and appears plumper bodied, flying with looser, languid and more elastic wingbeats, and shorter, more swooping glides. Nevertheless, good views and, preferably also, experience are necessary to appreciate these differences.

Dark, large-billed gadfly  petrel with white abdomen  , and wedge-shaped tail  ; elongated body, with long neck  but relatively small head , and very stout, bulbous bill . Long-winged, particularly the ‘arm’.

Recalls smaller Phoenix Petrel (Pterodroma alba), and there is extensive overlap between their at-sea ranges in the East Pacific (1 Spear, L. B., S. N. G. Howell, and D. G. Ainley (1992). Notes on the at-sea identification of some Pacific gadfly petrels (genus: Pterodroma). Colonial Waterbirds 15:202–218. Close ), but is larger-billed, with different underwing pattern (lacking diagnostic whitish leading edge), pale tail base (1 Spear, L. B., S. N. G. Howell, and D. G. Ainley (1992). Notes on the at-sea identification of some Pacific gadfly petrels (genus: Pterodroma). Colonial Waterbirds 15:202–218. Close ), and throat has no white (this feature is variable in P. alba) (1 Spear, L. B., S. N. G. Howell, and D. G. Ainley (1992). Notes on the at-sea identification of some Pacific gadfly petrels (genus: Pterodroma). Colonial Waterbirds 15:202–218. Close ); however, all of these features are difficult to see at longer range, when the more albatross-like appearance of P. rostrata (narrower wings usually held straight and perpendicular to body) becomes useful (Pterodroma alba usually holds wings slightly forward and bent at carpal joint) (1 Spear, L. B., S. N. G. Howell, and D. G. Ainley (1992). Notes on the at-sea identification of some Pacific gadfly petrels (genus: Pterodroma). Colonial Waterbirds 15:202–218. Close ). Atlantic Petrel (Pterodroma incerta) also has a white abdomen, but differs in having a brown vent and undertail-coverts, and plain central underwing; in worn plumage looks paler and grayer, with paler throat, and dark patch around eye. Separation of Beck’s Petrel (P. becki) is covered under that species.

Natal down

Apparently undescribed.

Juvenile

Similar to adult.

Adult

Nominate race has plain dark brown hood and upperparts, often slightly darker on hood and paler on rump and uppertail-coverts; underwing dark brown with slightly paler remiges and whitish line along median coverts; dark hood extending through side of breast to axillaries, undertail-coverts white, often with variable amount of brown spots or blotches. Female averages slightly smaller in most measurements.

No published information.

Bill

Black (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Iris

Dark brown (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Legs and Feet

Legs and base of feet pale pink to pale flesh, rest of feet black (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Linear Measurements

Overall length 38–40 cm (P. r. rostrata), or 38–42 cm (3 Howell, S. N. G., and K. Zufelt (2019). Oceanic Birds of the World. Princeton University Press, Princeton, NJ, USA. Close ).

Linear measurements (in mm, mean plus standard deviation, from de Naurois and Erard 4 de Naurois, R. and Erard, C. (1979). L’identité subspécifique des populations neo-calédoniennes de Pterodroma rostrata Peale 1848. L'Oiseau et la R.F.O. 49:235–239. Close , and range plus mean from Murphy 5 Murphy, R. C. (1928). Birds collected during the Whitney South Sea Expedition. IV. American Museum Novitates 322:1–5. Close ).

Mass

315–506 g (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Wingspan

84 cm (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ) or 101–108 cm (3 Howell, S. N. G., and K. Zufelt (2019). Oceanic Birds of the World. Princeton University Press, Princeton, NJ, USA. Close ).

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Until recently considered conspecific with Beck’s Petrel (Pseudobulweria becki) (which see) (6 Jouanin, C., and J.-L. Mougin (1979) Order Procellariformes. Pages 48-121 in Check-list of birds of the world, Volume 1, wecond edition (E. Mayr and G. W. Cottrell, editors). Museum of Comparative Zoology, Cambridge, Massachusetts, USA. Close ). P. aterrima was also considered a race of the present species (6 Jouanin, C., and J.-L. Mougin (1979) Order Procellariformes. Pages 48-121 in Check-list of birds of the world, Volume 1, wecond edition (E. Mayr and G. W. Cottrell, editors). Museum of Comparative Zoology, Cambridge, Massachusetts, USA. Close ), but a comprehensive molecular phylogeny of the group confirms species status for all of these taxa (7 Bretagnolle, V., Attié, C. and Pasquet, E. (1998). Cytochrome-b evidence for validity and phylogenetic relationships of Pseudobulweria and Bulweria (Procellariidae). Auk 115(1):188–195. Close ,8 Gangloff, B., H. Shirihai, D. Watling, C. Cruaud, A. Couloux, A. Tillier, E. Pasquet, and V. Bretagnolle (2012). The complete phylogeny of Pseudobulweria, the most endangered seabird genus: systematics, species status and conservation implications. Conservation Genetics 13(1):39–52. Close ).

Only differences afforded nomenclatural recognition are mensural (see Measurements), but some West Pacific birds have a broad whitish stripe on the underwing (3 Howell, S. N. G., and K. Zufelt (2019). Oceanic Birds of the World. Princeton University Press, Princeton, NJ, USA. Close ).

Two subspecies recognized, although it has been suggested that the species might be better considered monotypic (8 Gangloff, B., H. Shirihai, D. Watling, C. Cruaud, A. Couloux, A. Tillier, E. Pasquet, and V. Bretagnolle (2012). The complete phylogeny of Pseudobulweria, the most endangered seabird genus: systematics, species status and conservation implications. Conservation Genetics 13(1):39–52. Close ).

P. r. rostrata (Peale, 1848)—west-central Pacific Ocean, breeding in Fiji, American Samoa, Society Islands, Marquesas Islands, Gambier Islands, and possibly also on Rarotonga (Cook Islands).

P. r. trouessarti (Brasil, 1917)—tropical and subtropical Pacific Ocean, breeding in Vanuatu and New Caledonia. Much like the nominate, but has a slightly larger bill on average.

Occurs across the tropical and subtropical Pacific Ocean, breeding in Fiji, American Samoa, the Society Islands, Marquesas Islands, Gambier Islands, Vanuatu, and New Caledonia, and possibly also on Rarotonga, in the Cook Islands. Recorded in comparatively large numbers between the equator and 10ºN, and 150–100ºW (9 Pitman, R. L. (1986). Atlas of Seabird Distribution and Relative Abundance in the Eastern Tropical Pacific. Southwest Fisheries Center, La Jolla, CA, USA. Close ).

Marine and highly pelagic, rarely approaching land except at colonies. Breeds on volcanic islands, occupying hills and slopes usually on crests and narrow ridges, but also at the base of cliffs, always with dense covering of trees and shrubs, at elevations of 200–2,000 m, and up to 12 km inland on Tahiti, but also nests on low coralline islands (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ,10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ).

Very little known, but recorded all year in the vicinity of its breeding islands. However, the species also disperses across tropical and subtropical waters of the Pacific, apparently preferring waters with surface temperatures of > 25ºC, and abundance in equatorial and subtropical waters of the East Pacific is perhaps related to El Niño events (11 Ribic, C. A., D. G. Ainley, and L. B. Spear (1992). Effects of El Niño and La Niña on seabird assemblages in the equatorial Pacific. Marine Ecology Progress Series 80:109–124. Close ). Race <em>trouessarti</em> is said to range north at sea from New Caledonia as far as the Bismarck archipelago (12 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ); some occur off eastern Australia during November–April (13 Wood, K.A. (1990). Seasonal abundance and marine habitats of Procellaria fulmarine and gadfly petrels off central New South Wales. Notornis 37(2):81–105. Close ) south to central New South Wales ( 2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ), and around New Guinea (14 Coates, B. J. (1985). The Birds of Papua New Guinea. Volume 1. Non Passerines. Dove Publications, Alderley, Queensland, Australia. Close ,15 Beehler, B. M., T. K. Pratt, and D. A. Zimmerman (1986). Birds of New Guinea. Princeton University Press, Princeton, NJ, USA. Close ,16 Bailey, S.F. (1992). Seabirds of Madang Province, Papua New Guinea, September–November 1989. Emu 92(4):223–232. Close ), where there are regular sightings off Port Moresby (17 Tarburton, M. (2009). New birds and other interesting sightings from Melanesia. Muruk 9(2):56–91. Close ). Also recorded off Taiwan, in the Timor and Banda Seas (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ,18 Johnstone, R. E., and S. (B.) van Balen (2013). The birds of the Kai and Tayandu Islands, Maluku region, Indonesia. Western Australian Naturalist 29(1):11–56. Close ), with three records north to the Philippines (Luzon, May 1926; Negros, August 1963; Babuyan Islands, April 2004) (19 Dickinson, E. C., R. S. Kennedy, and K. C. Parkes (1991). The Birds of the Philippines: An Annotated Check-list. B.O.U. Check-list 12. British Ornithologists' Union, Tring, Hertfordshire, UK. Close ,20 Allen, D., C. P. Española, G. Broad, C. Oliveros, and J. C. T. Gonzalez (2006). New bird records for the Babuyan Islands, Philippines, including two first records for the Philippines. Forktail 22:57–70. Close ), and several south to northern New Zealand (all in June–August 1988) (21 Powlesland, R.G. and Pickard, C.R. (1992). Seabirds found dead on New Zealand beaches in 1988, and a review of Puffinus species recoveries, 1943 to 1988. Notornis 39(1):27–46. Close ,22 Gill, B. J., B. D. Bell, G. K. Chambers, D. G. Medway, R. L. Palma, R. P. Scofield, A. J. D. Tennyson, and T. H. Worthy (2010). Checklist of the Birds of New Zealand, Norfolk and Macquarie Islands, and the Ross Dependency, Antarctica. 4th edition. Ornithological Society of New Zealand & Te Papa Press, Wellington, New Zealand. Close ), and in East Pacific, between western Mexico (north to Colima (23 Howell, S. N. G., and S. Webb (1995). A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York, NY, USA. Close ) and Revillagigedo Islands, May 1990 (24 Santaella, L. and Sada, A.M. (1991). The avifauna of the Revillagigedo Islands, Mexico: additional data and observations. Wilson Bulletin 103(4):668–675. Close ) and southeast Hawaii, in November 1984 (25 Spear, L. B., D. G. Ainley, and P. Pyle (1999). Seabirds in southeastern Hawaiian waters. Western Birds 30(1):1–32. Close ) south to the waters off Peru (26 Ballance, L.T., Pitman, R.L., Spear, L.B., and Fiedler, P.C. (2002). Investigations into temporal patterns in distribution, abundance, and habitat relationships within seabird communities of the eastern tropical Pacific. NOAA Administrative Report LJ-02-17. Southwest Fisheries Science Center, CA, USA. Close ,27 Donegan, T. M., T. Ellery, J. A. Pacheco, J. C. Verhelst, and P. Salaman (2018). Revision of the status of bird species occurring or reported in Colombia 2018. Conservación Colombiana 25:4–47. Close ,28 Eisermann, K. and Avendaño, C. (2018). An update on the inventory, distribution and residency status of bird species in Guatemala. Bull. Brit. Orn. Club 138(3):148–229. Close ). A record west of Cape Comorin (India) was either P. rostrata or, more likely, Atlantic Petrel Pterodroma incerta (29 van den Berg, A.B., Smenk, C., Bosman, C.A.W., Haase, B.J.M., van den Niet, A.M. and Cadee, G.C. (1991). Barau’s Petrels Pterodroma baraui, Jouanin’s Petrels Bulweria fallax and other seabirds in the northern Indian Ocean in June-July 1984 and 1985. Ardea 79(1):1–14. Close ,30 Robertson, A.L.H. (1994). Occurrence of some pelagic seabirds (Procellariiformes) in waters off the Indian subcontinent. Forktail 10:129–140. Close ,31 Praveen, J., R. Jayapal, and A. Pittie (2013). Notes on Indian rarities–1: Seabirds. Indian Birds 8(5):113–125. Close ), but there is a photographic record from the Chagos Islands, in November 2012 (32 Carr, P. (2015). Birds of the British Indian Ocean Territory, Chagos archipelago, central Indian Ocean. Indian Birds 10(3–4):57–70. Close ), while sight records off Delagoa Bay, southern Mozambique, in November 1987 and December 1990 (33 Lambert, K. (2004). Does the Tahiti Petrel Pseudobulweria rostrata visit the western Indian Ocean? Marine Ornithology 32(2):183–184. Close ), one photographed off Durban, South Africa, in November 2018 (34 Allan, D. G., and N. D. Perrins (2019). First confirmed African record of Tahiti Petrel Pseudobulweria rostrata. Marine Ornithology 47(1):95–97. Close ), and another, also photo-documented, off southern Oman, in February 2019 (Facebook), hint that P. rostrata might regularly penetrate the western Indian Ocean during the non-breeding season. Even more exceptional is the single Atlantic Ocean record, off Cape Hatteras, North Carolina, USA, in late May 2018 (Seabirding blogspot).

All recorded observations involve surface-seizing (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Diet basically unknown, although recorded taking the sea skaters Halobates splendens, H. micans, H. sericeus (35 Cheng, L., L. B. Spear, and D. G. Ainley (2010). Importance of marine insects (Heteroptera: Gerridae, Halobates spp.) as prey of eastern tropical Pacific seabirds. Marine Ornithology 38(2):91–95. Close ). Has been recorded in association with other feeding seabirds  and also with surfacing pilot whales (Globicephala sp.). No further information available.

Nominate rostrata utters long, elaborate series of whistles terminating with a hooting sound at its breeding grounds, either in flight or from the ground, both within and outside its burrow (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); these apparently differ from those of trouessarti (36 Thibault, J.-C., and V. Bretagnolle (1999). Breeding seabirds of Gambier Islands, Eastern Polynesia: numbers and changes during the 20th century. Emu 99(2):100–107. Close ), which are described as being a long upslurred series of whistles (in flight) or a drawn-out braying whistle comprised of five main parts—a hiccup, pause, harmonics, whistle and moan—and usually given from ground (12 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ). In American Samoa (rostrata) both a ground call and an aerial call have been heard; the ground call consists of seven parts that allow variation to occur in duration and frequency in any portion of the call; the aerial call appears to be a condensed version of the ground call, used when approaching the colony in fog and darkness, and may have echolocating qualities (37 Rauzon, M.J. and Rudd, A.B. (2014). Vocal repertoire of Tahiti Petrel Pseudobulweria rostrata: a preliminary assessment. Marine Ornithology 42(2):143–148. Close ).

Laying dates for nominate rostrata are dispersed throughout year on Tahiti, Raiatea, and the Marquesas (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ), although peak egg-laying on Tahiti is apparently during March–July, with most fledglings recovered there between July and September (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ), and overall season probably March–October (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Forms loose colonies; nests in burrows or rock crevices, at up to 500 m elevation on Grand Terre, New Caledonia  (race trouessarti) (12 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ), and elsewhere perhaps formerly up to 1,900 m (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ). Single egg, size 70 mm × 45 mm, mass 72 g (n = 1) (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); no data on incubation and fledging periods (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ).

Not globally threatened. Currently considered Near Threatened. Poorly known. Overall population probably between 10,000 and 30,000 pairs, although (BirdLife International 2016) suggests that there might be only 10,000–20,000 mature individuals. Reported to be the commonest petrel at sea in the seas around Fiji (38 Shirihai, H., T. Pym, J. Kretzschmar, K. Moce, A. Taukei, and D. Watling (2009). First observations of Fiji Petrel Pseudobulweria macgillivrayi at sea off Gau Island, Fiji, in May 2009. Bulletin of the British Ornithologists’ Club 129(3):129–148. Close ). Nominate race is currently regarded as Near Threatened and is seen regularly, with breeding populations in tropical Pacific estimated at < 500 pairs on Marquesas, with at least formerly < 1,000 pairs on Tahiti, and several thousand pairs on Moorea (both in the Society Islands), but probably fewer in recent years, and c. 12–26 pairs on three islands in the Gambiers, where first detected in 1995 (36 Thibault, J.-C., and V. Bretagnolle (1999). Breeding seabirds of Gambier Islands, Eastern Polynesia: numbers and changes during the 20th century. Emu 99(2):100–107. Close ,39 Waugh, S., Champeau, J., Cranwell, S. and Faulquier, L. (2013). Seabirds of the Gambier Archipelago, French Polynesia in 2010. Marine Ornithology 41(1):7–12. Close ), with unknown populations in Fiji, American Samoa, and possibly still in the Cook Islands (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ,10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ), but that in Vanuatu is apparently extinct; introduced rats (Rattus spp.) and feral cats (Felis catus) are abundant on many island groups in this part of the Pacific, while predator control is urgently required even within protected areas such as the American Samoa National Park (40 Rauzon, M.J. (2007). Island restoration: exploring the past, anticipating the future. Marine Ornithology 35(2):97–107. Close ), and the permanent opening of tracks and roads into mountainous areas has accelerated access for predators to this species’ breeding areas (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ). Natural predators include Swamp Harrier Circus approximans (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ). Until the 1970s the species was subject to some harvesting by humans, especially in the Society Islands, with adults being taken at their nests, and their body feathers used as fishing lures (10 Thibault, J.-C., and A. Cibois (2017). Birds of Eastern Polynesia. A Biogeographic Atlas. Lynx Edicions, Barcelona, Spain. Close ). Race trouessarti breeds (hundreds or thousands of pairs) (41 de Naurois, R. (1978). Procellariidae reproducteurs en Nouvelle-Calédonie. Comptes Rendus Acad. Sci. Paris (Ser D) 287:269–271. Close ,12 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ) on Grand Terre, New Caledonia, and on eleven (of 70) islets in its southern lagoon (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); this race is threatened by nickel mining and by feral pigs (Sus scrofa), cats and wild dogs, with evidence of decreases in recent decades on some of these islets, although rats have now been eradicated. Light-induced mortality, which typically affects recently fledged juveniles more than adults, is a threat in French Polynesia and New Caledonia, although rescue schemes are in place on some of the relevant islands (42 Le Corre, M., A. Ollivier, S. Ribes, and P. Jouventin (2002). Light-induced mortality of petrels: a 4-year study from Réunion Island (Indian Ocean). Biological Conservation 105(1):93–102. Close ).