Gadfly Petrels

Genus Pterodroma, Pseudobulweria and Lugensa

The Gadfly Petrels vary in size from rather small birds such as the Cookilaria-species, measuring about 26 cm,  to the much larger and robust representatives of this group like the White-headed Petrel  with an overall length of about 43 cm. Their plumages also vary a great deal from species to species; from completely black to light grey mantles and pure white bellies, and with different color phases within species. One feature shared by all of them is the black bill of which the shape also shows much variation. Some species are extremely rare and restricted to a very limited area,  other are abundant and wander widely or have unknown pelagic ranges.

Taxonomy

The group of the Gadfly Petrels counts over 35 species, mainly from the Southern Hemisphere. There are three genera: Pterodroma with about 30 species, Pseudobulweria counting four and Lugensa with only one. Many authors have tried to classify the large number of species of this group and to determine their relationships. This has resulted in a division in several subgenera and the grouping of several species which are considered to have a more or less close relationship. The taxonomic discussion has not come to an end yet: new species have been added or split recently and probably will be in the near future.

Cookilaria Group

Genus Pterodroma

Subgenus Cookilaria

  • Cook's Petrel Pterodroma cookii. Pacific Ocean, breeds off New Zealand and western South America.
  • Pycroft's Petrel Pterodroma pycrofti. Breeds off northern New Zealand moving into tropical Pacific.
  • Gould's Petrel Pterodroma leucoptera, South Pacific. Two subspecies:
    • P. l. leucoptera, breeding Cabbage Tree I.
    • P. l. caledonica, breeding New Caledonica
  • Collared or White-throated Petrel Pterodroma brevipes.Split from P. leucoptera, South Pacific, breeding Fiji group.
  • De Filippi's or Mas a Tierra Petrel Pterodroma defilippiana. Juan Fernandez Islands, eastern Pacific.
  • Stejneger's Petrel Pterodroma longirostris


Cook's Petrel Pterodroma cookii Mangawhai Heads, N.I, New Zealand
Culmen: 27.3 mm; Total: 70.3 mm; unsexed adult

Hallstroma Group

Genus Pterodroma

Subgenus Hallstroma

  • Phoenix Petrel Pterodroma alba, central tropical Pacific, breeding Phoenix, Line, Marquesas Is., Tonga and Pitcairn Is.
  • Trinidade or South Trinidad Petrel Pterodroma arminjoniana, breeding Trinidade I., Martin Vas Rocks, Round I. near Mauritius.
  • Herald Petrel Pterodroma heraldica, breeding many islands in southern Pacific.
  • Henderson Petrel Pterodroma atrata; recent split from P. arminjoniana. Pacific Ocean, breeding Pitcairn I.
  • Galapagos Petrel Pterodroma phaeopygia, Pacific Ocean, breeding Galapagos Archipelago.
  • Hawaiian Petrel Pterodroma sandwichensis, central Pacific, breeding Hawaiian chain.
  • Kermadec Petrel Pterodroma neglecta, southern Pacific. Two subspecies:
    • P. n. neglecta, breeding Lord Howe, Kermadec, Austral and Pitcairn Is., Easter I.
    • P. n. juana, breeding San Ambrosio and San Felix Is., Mas a Tierra and Santa Clara Is.
  • Juan Fernandez Petrel Pterodroma externa, tropical Pacific Ocean, breeding Mas Afuera and Juan Fernandez Is.
  • Barau's Petrel Pterodroma baraui, tropical and subtropical Indian Ocean, breeding Reunion and Rodriguez.

Pterodroma group

Genus Pterodroma

Subgenus Pterodroma

  • Murphy's Petrel Pterodroma ultima. Central South Pacific, breeding Austral, Tuamotu, Pitcairn, Rapa, Oeno Is.
  • Providence or Solander's Petrel Pterodroma solandri. Western tropical Pacific, breeds off eastern Australia.
  • Great-winged or Grey-faced Petrel Pterodroma macroptera. Almost circumpolar in southern oceans. Two subspecies:
    • Great-winged Petrel P. m. macroptera. Breeds Tristan da Cunha, Gough, Crozet, Marion, Pr. Edward, Amsterdam, Kerguelen Is. and some islands off Australia.
    • Grey -faced Petrel P. m. gouldi. Breeds off New Zealand
  • Taiko or Magenta Petrel Pterodroma magentae. Pacific Ocean, very rare, breeding Chatham Is.
  • White-headed Petrel Pterodroma lessonii. Circumpolar southern oceans.
  • Atlantic or Schlegel's Petrel Pterodroma incerta. Temperate southern Atlantic Ocean.
  • Black-capped Petrel Pterodroma hasitata. Caribbean Sea and western tropical Atlantic. Two subspecies:
    • P. h. hasitata, breeding Haiti. Dominican Republic and Dominica.
    • Jamaican Petrel P. h. caribbea. Breeding Jamaica, but probably extinct.
  • Bermuda Petrel or Cahow Pterodroma cahow. Around Bermuda Is., recently recorded on Azores.


Grey-faced Petrel Pterodroma macroptera gouldi Mangawhai Heads, NI, New Zealand
Culmen: 36.7 mm; Total: 89.6 mm; unsexed immature.

Unknown Pterodroma sp. Probably an old male P. lessonii Location unknown
Total: 95.5 mm

Mollis group

Genus Pterodroma

Subgenus Pterodroma

  • Soft-plumaged Petrel Pterodroma mollis. Two subspecies:
    • P. m. mollis. Atlantic Ocean, breeding Tristan de Cunha group and Gough I.
    • P. m. dubia. Indian Ocean, breeding Prince Edward, Crozet en Kerguelen Is.
  • Fea's Petrel Pterodroma feae. Subtropical North Atlantic Ocean, breeding Cape Verde Is.
  • Desertas Petrel Pterodroma desertas. Breeding Deserta Is.
  • Zino's Petrel Pterodroma madeira. North Atlantic Ocean, very rare, breeding Madeira.


Soft-plumaged Petrel Pterodroma m. mollis. Gough Island
Culmen: 28,6 mm; total 76.3 mm; unsexed adult Courtesey of B. Zonfrillo, Univ. of Glasgow

Proastrelata Group

Genus Pterodroma

Subgenus Proastrelata

  • Chatham Island Petrel Pterodroma axillaris. Around Chatham Is. Possibly  moving eastward in southern Pacific.
  • Black-winged Petrel Pterodroma nigripennis
  • White-necked Petrel Pterodroma cervicalis. Tropical Pacific Ocean. Two subspecies:
    • White-necked Petrel P. c. cervicalis. Kermadec Is, Norfolk Is.
    • Vanuatu or Falla's Petrel P. c. occulta. Vanuatu
  • Mottled, Scaled or Peale's Petrel Pterodroma inexpectata. Pacific Ocean, breeding New Zealand area.
  • Bonin Petrel Pterodroma hypoleuca, northwestern Pacific, breeds Bonin and Izu is.

Pseudobulweria Petrels

Genus Pseudobulweria

This group differs from the other Pterodroma petrels by having latericorns forming a notch with the upper nail of the bill and more laterally compressed bill.  More about this.

  • Mascarene or Reunion Petrel Pseudobulweria aterrima. Very rare, collected at Reunion, distribution unknown.
  • Tahiti Petrel Pseudobulweria rostrata. Tropical Pacific Ocean, Two subspecies:
    • P. r. rostrata., Breeding Society and Marquesas Is.
    • P. r. trouessarti. Breeding New Caledonia
  • Beck's Petrel Pseudobulweria becki. Western Pacific, until recently only two specimens known, but recently rediscovered. Split from P. rostrata
  • Fiji Petrel Pseudobulweria macgillivarayi. Very rare in Pacific around Fiji Is.

Kerguelen Petrel

Genus Lugensa

Only one species

  • Kerguelen Petrel Lugensa brevirostris. Circumpolar southern oceans.


Kerguelen Petrel Lugensa brevirostris. Culmen: 27.3; total: 78.9 mm
Courtesey of J.A. van Franeker, Imares

Osteology

  • Skull
  • Flight aparatus
  • Pelvis and legs
  • Vertebrae and ribs

References