Essential Giant Petrel Information

The Giant Petrel is a prominent seabird in the Southern Ocean, known for its powerful build and aggressive scavenging behavior. Often nicknamed “Stinkers” or “Gluttons,” these birds are fierce predators and scavengers. There are two species: the Northern and Southern Giant Petrel, classified as separate species in 1966. The Northern species inhabits areas north of the Antarctic Convergence Zone, while the Southern species ranges from Antarctica to subtropical regions.

Size and Appearance

Often mistaken for albatrosses, Giant Petrels have an impressive wingspan of up to 2.1 meters (7 feet) and can weigh as much as 7.7 kilograms (17 pounds). They share similar dark, mottled grey-brown feathers and a slender, hooked orange bill, perfect for grabbing prey or tearing at carrion. A key difference between the species is the bill color—Southern Giant Petrels have red-tipped bills, while Northern Giant Petrels have green-tipped bills. Interestingly, about 15% of Southern Giant Petrels are nearly all white due to a genetic trait.

Feeding and Behavior

Giant Petrels are aggressive hunters and scavengers, preying on unprotected chicks and weak or dead adult animals, including penguins. They are known to fight over carcasses, using their wings to defend their finds from other petrels. Out at sea, they feed on fish, squid, and krill, often following ships in hopes of scavenging discarded fish or waste.

Both species produce a waxy stomach oil, which sustains them on long flights or feeds their chicks. This oil can be used as a defense mechanism—when threatened, Giant Petrels can projectile vomit the foul-smelling liquid to deter predators.

Conservation and Breeding

Giant Petrels are often seen following ships, but are more cautious when nesting. It's important to maintain a distance of 25-50 meters from nesting sites, in contrast to the 5-10 meters allowed near penguin colonies. Both species breed on South Georgia, though Southern Giant Petrels also breed in the South Shetlands and other Antarctic locations.

Interesting Facts

• Bill Color: Southern Giant Petrels have red-tipped bills, while Northern ones have green-tipped bills.
• Aggressive Scavengers: They hunt chicks and scavenge carcasses, defending their finds with their wings.
• White Morphs: About 15% of Southern Giant Petrels display an almost entirely white plumage.
• Stomach Oil Defense: They can projectile vomit a smelly liquid as a defense mechanism.