Northern Giant Petrel vs Southern Giant Petrel

Northern Giant Petrel

Macronectes halli

Huge4.2 kgMarine

The northern giant petrel averages 90 cm (35 in) in length, with a range of 80 to 95 cm (31 to 37 in), possessing a wingspan of 150 to 210 cm (59 to 83 in). Size is somewhat variable and this species is broadly the same size as its southern sister species. The largest-bodied colony is in the South Georgia Islands, where 56 males averaged 4.9 kg (11 lb) and 43 females average 3.72 kg (8.2 lb). The smallest-bodied are on the Chatham Islands, where 19 males averaged 3.66 kg (8.1 lb) and 21 females averaged 2.83 kg (6.2 lb). Overall, weight for the species can range from 2.5 to 5.8 kg (5.5 to 12.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Sergio Garrido Villa · CC BY 4.0

Southern Giant Petrel

Macronectes giganteus

Huge3.6 kgMarine

The southern giant petrel measures 86 to 99 cm (34–39 in) with a wingspan of 185 to 205 cm (6 ft 1 in – 6 ft 9 in). Both this and the northern giant petrel vary considerably in size, with southern colonies averaging larger than northern colonies, in line with Bergmann's rule. Due to the large amount of size variability, it is difficult to determine which is the larger species, but the largest-bodied colonies of the southern species are slightly larger on average, in both mass and linear dimensions, than the largest in the northern giant petrel.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Brocken Inaglory · Public domain

Photos and recordings are credited to their authors under the licence shown. Full profiles: Northern Giant Petrel and Southern Giant Petrel.