Fea's Petrel 117 



were medium gray, darker on the wing coverts. The bill was dark 

 gray or black. 



Taxonomy and identification — Various field guides on board indi- 

 cated that the bird must belong to one of the North Atlantic gadfly 

 petrels closely related to the soft-plumaged petrel P. mollis. The wholly 

 dark underwing eliminated all other Pterodroma that have been docu- 

 mented as occurring in the North Atlantic (i.e., Pterodroma hasitata, 

 P. cahow [Nichols and Mowbray], P. arminjoniana [Giglioli and 

 Salvadori]). The gray coloration, contrast between back and tail, dark 

 bill, and wholly white underparts ruled out similar petrels from other 

 oceans (i.e., Lugensa brevirostris Lesson, Pterodroma incerta Bonaparte, 

 Procellaria cinerea Gmelin). The soft-plumaged petrels, formerly treated 

 as four or more subspecies (e.g., Mathews 1934, Harrison 1983), have 

 recently been reclassified as three distinct species, Pterodroma madeira 

 Mathews, P. feae (Salvadori), and the nominate P. mollis (Bourne 

 1983a, Imber 1985, Zino and Zino 1986; see also Sibley and Ahlquist 

 1990, Warham 1990). All three forms may appear to have various 

 shades of dark gray-brown above, depending upon feather wear and 

 lighting conditions (Enticott 1991). The nominate soft-plumaged petrels 

 from the southern hemisphere are normally darkest, with variable gray 

 markings extending across the upper breast and shading into the white 

 face and chin above but contrasting sharply with the white belly 

 below (Fig. 1). Thus, these birds appear to have a dark head and 

 neck but pale face contrasting with white underparts. Some southern 

 soft-plumaged petrels have a prominent "W" mark on the wing, some 

 have noticeably paler rumps, and in some, the underwing shows variable 

 amounts of contrasting white coloration. The North Atlantic forms are 

 known as the Freira petrel (P. madeira) and Fea's petrel (P. feae: 

 see Bannerman and Bannerman 1966; known also as "gon-gon" petrel 

 on the Cape Verde Islands [Bourne 1983a, Collar and Stuart 1985]). 

 These two species are both normally paler and grayer above than the 

 nominate, with the entire body white below (Fig. 2, personal observation, 

 J. Enticott personal communication). The amount of black around the 

 eye in these forms ranges from conspicuous to essentially lacking. In 

 general, photographs we examined indicated that both the underwings 

 and upperwings are more uniformaly colored in the North Atlantic 

 species. 



The Freira petrel and Fea's petrel are difficult to separate on 

 the basis of plumage alone (Bourne 1983a, Fisher 1989). Fea's petrel 

 is larger and is known to nest (in winter) only on the Cape Verde 

 Islands and on Bugio (in the Desertas group), although there are 

 recent sight and vocalization records from the Azores (Bibby and del 

 Nevo 1991) and from Great Salvage Island 300 km south of the 



