52 Broad-billed Dove-Petrel (Blue-), Whale-Bird, Prion, P. vittatus, S. Oceans.
c. ocean 11.5
Upper delicate blue-gray; head darker than back; edge shoulder, wing, tip-tail black; under, line over eye, white; flanks blue; broad bill blue tipped black; feet light-blue; f., sim. Cuttlefish.
r. ocean 10
Like 52, but bill narrower and paler blue-gray; expanded wings show black marks like letter W. Food as 54.
54 Dove-Petrel, Dove-like-Petrel (-Prion), Whale-Bird (Snow-), P. desolatus, S. Oceans.
c. ocean 10.5
Like 52, 53, but more delicate; blackish below eye; white stripe above eye; head same as back; bill straighter, more slender; f., smaller. Shellfish, oily substances.
55 Fairy Dove-Petrel (-Prion), Short-billed (Gould) Blue-Petrel, P. brevirostris (ariel), S. Indian O., A., Bass St., Madeira, S. Africa.