Tuatara: Volume 21, Issues 1 and 2 (New Zealand Albatrosses and Petrels: an Identification Guide)
9. Yellow-Nosed Mollymawk — (Diomedea chlororhynchus) — Plate 5
9. Yellow-Nosed Mollymawk
Field Characters: 183/76. This, the smallest and most slender looking of the mollymawks, is a rare visitor to New Zealand. It superficially resembles the Black-browed Mollymawk (6) but lacks the black eyebrow. Head, neck and underbody white with sharply defined black mantle, upperwings and tail. The underwing resembles that of Buller's Mollymawk (8). Juveniles, except for their bill colour, are similar to adult birds.
The bill is slender and comparatively much longer than that of other mollymawks. It is black with a bright yellow upper margin, turning red at the tip in adults, whereas the bills of juveniles are uniformly black. Feet pinkish blue with flesh-coloured webs.page 24
Differs from Black-browed Mollymawk (6) by its smaller size, bi-coloured bill and in underwing pattern.
Flight as for other mollymawks. Sometimes follows ships for short periods.
Breeds Tristan de Cunha, Gough and St. Paul Islands. Ranges into warmer parts of the Tasman Sea, mainly in winter. Has been recorded from the Hauraki Gulf, Three Kings and Bay of Plenty.