1. tahiti Petrel Pseudobulweria rostrata WS 84cm TL 39cm See p.160
A medium-sized petrel with very long, narrow wings held straight and at right angles to body, with flight feathers appearing to curl up at wing-tips. Long body and long tapering tail, long neck and small head make heavy bill look especially large. In range, difficult to distinguish from Phoenix; could be confused with pale phases of Herald and Kermadec (20:3) Petrels and possibly with Wedge-tailed Shearwater (32:2). Tahiti is probably best distinguished from all by long, straight-winged jizz and distinctive flight. The two races, rostrata and trouessarti, are not separable at sea.1a
Underparts Head dark; breast, belly and undertail white, slightly scruffy around edges; underwing dark with slightly paler central panel, especially on innerwing.1b
Upperparts Dark except for slightly paler sides to rump and uppertail, especially obvious in worn plumage.1c
Head Large, deep and heavy bill characteristic of Pseudobulweria.2. beck’s Petrel Pseudobulweria becki WS ? TL 29cm See p.159
Medium to small Pseudobulweria, essentially a small version of Tahiti Petrel, known almost entirely from museum specimens.2a
Upperparts Dark except for slightly paler sides to rump and uppertail, especially obvious in worn plumage.Underparts as Tahiti.
3. Phoenix Petrel Pterodroma alba WS 83cm TL 35cm See p.170
Medium-sized Pterodroma with similar plumage and range to Tahiti but Herald-like jizz and typical Pterodroma flight. In range difficult to distinguish from Tahiti; could be confused with pale phases of Herald and Kermadec (20:3) Petrels and possibly Wedge-tailed Shearwater (32:2). Herald and Kermadec have white patches on outer underwing; Kermadec has white flashes on upperwing; Wedge-tailed Shearwater is larger and broader-winged with lower, more leisurely flight. Magenta Petrel (19:3) from southern Pacific is very similar but is slightly larger and heavier and has whiter undertail-coverts.3a
Underparts Head dark with indistinct whitish throat; breast and belly white; undertail white, dark at tip;underwing usually looks dark but has thin white line along inner leading edge, somewhat paler bases to primaries and paler panel extending onto central inner wing.
3b
Upperparts Entirely dark.3c
Head Standard Pterodroma type bill; white chin and throat.4. fiji Petrel Pseudobulweria macgillivrayi WS ? TL 30cm See p.161
Small, poorly known Pseudobulweria that probably looks like a small all-dark Tahiti Petrel with a shorter, squarer tail. Known only from Gau Island in Fiji. Smaller than any other all-dark petrel or shearwater in range except for Bulwer’s (15:1) and dark-phase Collared Petrels (24:2). Also known as MacGillivray’s Petrel.4a
Underparts Entirely dark with silvery sheen on underwing.4b
Upperparts Entirely dark sooty-brown.1a
3a
5a
4a
3b
2a
3c
1c
4b
4c
1b
Plate 18: larGer Grey-and-WhIte PTeroDroMa Petrels of the PacIfIc
A group of large, long-winged, long-tailed petrels with plumage similar to the cookilarias (Plates 22–24); grey upperparts with dark M of varying intensity across open wings; white underparts and underwings with distinctively shaped dark marks from carpals.
1. White-necked Petrel Pterodroma cervicalis WS 97cm TL 43cm See p.176 1a
Underparts White; underwing white with dark line from carpal extends about halfway towards body; basesof primaries pale in 90% of birds; underwing can look entirely white at a distance and in strong light.
1b
Fresh plumage, upperparts White collar separates darker cap from pale grey back; broad white edges to feathers of back, narrower ones to tail and secondary coverts; dark M mark across upperwings reasonably obvious, much more so in some lights than others.1c
Worn plumage, upperparts Upperwings almost entirely dark; back darker, obscuring dark M mark; rump and uppertail-coverts can show white patches; collar can be a rather scruffy grey-white and crown very pale.2. vanuatu Petrel Pterodroma occulta WS 86cm? TL 39cm See p.177 2a
Fresh plumage, underparts Underwing same as White-necked but bases of primaries dark.3. Juan fernandez Petrel Pterodroma externa WS 97cm TL 43cm See p.177 3a
Underparts White; underwing white with very small dark line from carpal and a broken black line fromcarpal to primaries; underwing often looks entirely white.
3b
Upperparts Pale grey back joins grey cap; upperwings mostly dark, dark M not obvious; amount of white on uppertail-coverts varies to the extent that some may almost appear to have white rumps.3c
Upperparts Upperwings can show dark M in some lights and plumages; back, neck and cap can be very pale, making dark patch behind eye stand out.White-necked and Vanuatu can be distinguished from Juan Fernandez by white collar, except in a few cases of birds in very worn plumage when the larger dark underwing patch from the carpal should help. Note, however, that underwing of all species can look white at a distance and in strong light. Juan Fernandez has a heavier-looking bill. Vanuatu is 10% smaller than both and has dark bases to the primaries on the underwing. Note, however, that c.10% of White-necked do also, which would make size – rarely easy to judge – the only reliable criterion. All three species are paler and greyer than both Galápagos and Hawaiian, especially around the head.
4. Galápagos Petrel Pterodroma phaeopygia WS 95cm TL 42cm See p.179 4a
Underparts White, with most having some dark markings on the axillaries and flanks. Underwing white withdark primaries and trailing edge and broad dark line from carpal extending well in towards body. Very dark head and sides of breast contrast with white forehead and throat, although all can vary.
4b
Fresh plumage, upperparts At sea usually looks very dark but in fresh plumage feathers have a greyish sheen that can make the back and rump look paler grey.4c
Worn plumage, upperparts Very dark brownish-black; sides of rump and uppertail-coverts can show white patches.1a 3a
4a 5a
4b 5b 3b
1b
2a
1c
3c
4c
5c
Plate 19: PTeroDroMa Petrels WIth dark underWInGs and WhIte bellIes 1. White-headed Petrel Pterodroma lessonii WS 109cm TL 43cm See p.183
Large robust Pterodroma with long wings and long, wedge-shaped tail. Heavy-bodied with bull neck, stout bill and rounded head. White head and dark underwing unlike anything else, but check equally pale Mottled Petrel (23:4) and Southern Fulmar (12:1). Circumpolar in colder subantarctic waters.1a
Underparts Head and body white with black eye-patch and pale grey half collar; underwing dark with white line along inner leading edge and slightly paler bases to primaries and outer coverts.1b
Underparts At any distance looks basically white with entirely dark underwing.1c
Upperparts Pearly grey, dark on upperwings forming a poorly defined M mark across open wings.2. atlantic Petrel Pterodroma incerta WS 104cm TL 43cm See p.147
Large, heavy, long-winged Pterodroma with bull-necked appearance, rounded head, stout bill and tapering mid-length, slightly wedge-shaped tail, and some variability in plumage. Also known as Schlegel’s Petrel. Endemic to Tristan da Cunha and Gough Island, dispersing widely in South Atlantic. Magenta very similar in plumage and jizz but slightly smaller with narrower tail and white (not dark) undertail-coverts. Soft-plumaged can look dark-headed in poor viewing conditions. Lighter phases of Trindade Petrel (25:2a–b) have white patches on outer underwing.2a
Underparts Head dark with whitish throat. Lower breast and belly white and undertail dark. Underwing entirely dark with the usual slightly paler bases to primaries, obvious only in strong light.2b
Dark bird, underparts A few birds are entirely dusky on breast and belly.2c
Worn plumage, underparts Pale bases to feathers can show through on upper breast and throat.2d
Upperparts Entirely dark.3. Magenta Petrel Pterodroma magentae WS 102cm TL 38cm See p.184
Medium-large bulky looking Pterodroma with proportionally long wings and quite long, slightly wedge-shaped tail.Very rare, breeding only on Chatham Island. Magenta looks very similar to Phoenix (17:3) but is slightly larger and heavier and has whiter undertail-coverts. See Atlantic Petrel for separation from that species.
3a
Adult underparts Head dark with paler throat; breast, belly and undertail white with very few darker feathers at tip; underwing dark, paler and greyish on flight feathers.3b
Adult upperparts Entirely dark.3c
Juvenile head Some juveniles have small pale supercilium, and pale throat merging with white breast.4. soft-plumaged Petrel Pterodroma mollis WS 89cm TL 34cm
See p.185
Small, stout-bodied, compact Pterodroma with short, rounded tail and short neck. Widespread in South Atlantic, southern Indian Ocean and southwest Pacific. More southerly nominate mollis generally has a paler face and neck and narrower breast-band than more northerly race dubia. In good light, combination of upperwing pattern and dark underwing diagnostic but mistaken for many other species in poor conditions – see text. Similar to Northern Hemisphere Fea’s and Zino’s (21:4–5), but most Soft-plumaged have complete grey breast-band. See text for excep-tions. See Plate 14:5 for rare dark phase.1a
2c
2a
2b
3a
3b 2d
1c
1b
4d
4b
4a
3c
4c
Plate 20: larGer PTeroDroMa Petrels of the PacIfIc and IndIan oceans 1. trindade Petrel Pterodroma arminjoniana pale phase WS 98cm TL 37cm See p.172
Medium-sized, long, narrow-winged petrel with relatively long tail, usually held tightly closed in flight. Slightly heavier and more robust than Herald. Kermadec has white flashes on upperwing. See also Tahiti, Beck’s, Phoenix (17:1–3) and Magenta (19:3). See Plate 25:2 for complete range of plumages.1a
Pale phase (Round Island form), underparts White; rather pale scruffy breast, flanks and undertail;underwing, forewing dark; large white patch on outer wing, paler panel extending onto inner wing; narrow white line on inner forewing.
2. herald Petrel Pterodroma heraldica paler phases WS 95cm TL 35cm See p.171
Medium-sized, slim, long- and narrow-winged petrel of the Pacific with relatively long tail, usually held tightly closed in flight and appearing quite pointed. See Plate 16:4 for dark phase and Plate 25:1 for complete range of plumages.2a
Pale phase, underparts Belly, throat and lores white; breast, flanks and undertail dark; underwing as Trindade, tending to be darker on the inner wing.2b
Pale phase, upperparts All but the very lightest phases are dark with grey cast in fresh plumage, browner when worn; a few show a trace of dark M.2c
Intermediate phase, underparts Darker on head and throat, but lores usually remain pale.3. kermadec Petrel Pterodroma neglecta paler phases WS 92cm TL 38cm See p.173
Medium-sized Pterodroma of the Pacific with long broad wings, short squarish tail and relatively short, stubby bill.Kermadec Petrel has the widest range of plumages of all the polymorphic Pterodroma petrels, each so-called phase or morph grading into the others. At all ages and in all plumages Kermadec is best identified by pale bases to primaries on upperwing. See Plate 16:2 for dark phase and Plate 25:3 for complete range of plumages. The two races, neglecta and juana, are not separable at sea.
3a
Pale phase, underparts Palest birds have head and underparts almost entirely white except for pale brown mottling on crown, collar and flanks, darkening on undertail; underwing variable but always has a large white patch on outerwing, paler panel extending onto centre of innerwing and narrow white line on inner forewing.3b
Pale phase, upperparts Palest birds have greyish-fawn scalloping on white back, darkening on rump;upperwings darker with prominent white bases to shafts and outer flight feathers.