Southern Giant-Petrel vs Northern Giant-Petrel

In short

The Southern Giant-Petrel and Northern Giant-Petrel are large seabirds with overlapping ranges, but they can be distinguished by their bill coloration and plumage morphs. Southern Giant-Petrels have a more variable plumage with both dark and white morphs, while Northern Giant-Petrels are uniformly dark. Bill tip color is a key field mark: greenish for Southern and reddish for Northern.

Identification tips

• Bill tip color: Southern has a greenish bill tip, Northern has a reddish bill tip.
• Plumage morphs: Look for the white morph in Southern Giant-Petrels, which is absent in Northern.
• Diet observation: If observed feeding, note the type of prey; Southern often on carrion, Northern on live prey.
• Range and habitat: Consider proximity to shore; Southern often closer to coastlines.

Size

Both species are similar in size, being large and robust with long wings and a hefty build.

Plumage

Southern Giant-Petrels exhibit two color morphs: a dark morph and a rarer white morph, whereas Northern Giant-Petrels are consistently dark. The Southern's white morph can be a striking feature when present.

Behaviour

Southern Giant-Petrels primarily scavenge on carrion along coastlines, while Northern Giant-Petrels have a more varied diet that includes live marine prey like krill and squid.

Habitat

Both species inhabit the Southern Ocean, but the Southern Giant-Petrel is more commonly found scavenging near shorelines, whereas the Northern Giant-Petrel may be seen further offshore.