Giant Petrels

Genus Macronectes

The two Macronectes species are very large petrels of about the size of the smaller albatrosses or Mollymawks.
  • Southern Giant Petrel Macronectes giganteus
  • Northern Giant Petrel Macronectes halli

Evolution and taxonomy

According to Penhallurick & Wink (2004) the divergence of Fulmarus-Macronectes within the Fulmar lineage dates from ca 7.8 My ago and the two Giant Petrel types seem to have diverged from each other around 2.6 My ago. Bourne and Warham (1966) separated the two forms as full species: M. giganteus and M. halli. Recently Penhallurick & Wink (2004) made a plea for re-establishing the subspecific status of both forms based on their DNA analysis.
Hybrids between both (sub)species have occurred. Distinct forms on the Falklands, Gough Island and the Chathams may be subspecies of M. giganteus and M. halli respectively.


The Southern Giant Petrel is the commonest of the two and has a cricumpolar distribution in the Southern Hemisphere from Antarctica to subtropical waters. It breeds on many antarctic and subantarctic islands. The Northern Giant Petrel has also a circumpolar distribution but breeds on islands north of the Antarctic Convergence.


Being very ferocious scavengers they are equipped with heavy bills with an impressive hooked tip and long nasal tubes. Since Giant Petrels have the habit of scavenging in penguin rookeries and seal colonies they are good walkers, unlike the other Fulmars. Giant Petrels have been observed diving to depths of about three meters to submerged carrion, using wings and feet (Van den Hoff & Newbery 2006). They are very agile on the wing and fly with rigidly outstretched and narrow wings, but have a more flapping flight than abatrosses.


Giant Petrels are easily distinguished from the similarly sized Mollymawks by their long nasal tube, or in case of the bare skull, by the ‘hump’ of the upper mandible. Without bill sheaths there is no way to tell the two species of Giant Petrel apart with certainty. The lachrymals are fused, the cranium rounded. The coloration of the ramphoteca is yellowish to pinkish horn with a greenish tip in M. giganteus and a pinkish tip in M. halli.

Southern Giant Petrel Macronectes giganteus. Frazier Islands.
Culmen 93.8 mm; total: 168 mm, adult, unsexed adult, probably female
Courtesey of J.A. van Franeker & J. Creuwels

  • Flight apparatus
  • Pelvis and legs
  • Vertebrae and ribs