How to Identify Northern Giant Petrel Feathers

What Northern Giant Petrel's Feathers Look Like

The Northern Giant Petrel is a huge, heavy-bodied seabird, and unlike its close relative the Southern Giant Petrel, it does not have a white morph; all Northern Giant Petrels show some variation of dark brownish-gray plumage. Body feathers are a mottled grayish-brown, generally darker and more uniform on the back and wings, gradually paling to a lighter grayish or buffy-brown on the head and neck in older adults, a feather with an overall dark chocolate-brown to grayish-brown tone, sometimes with a paler, almost frosted-looking head/neck feather, fits this species well. Flight feathers are massive given the bird's size, 25-35 cm, dark brownish-gray with little contrasting pattern, reflecting a build suited to sustained ocean gliding rather than showy plumage. Tail feathers are similarly dark brownish-gray, 16-20 cm, unpatterned. Overall feather size is very large, among the biggest you're likely to find on a beach, and shafts are dark brown throughout. Because true albinistic/white-morph birds don't occur in this species (unlike the Southern Giant Petrel), an all-white or heavily white-speckled large petrel-type feather points away from Northern Giant Petrel.

Step-by-Step: Is This Feather From a Northern Giant Petrel?

• Check overall color. Uniform dark brownish-gray, sometimes paler on the head/neck, with no true white morph to consider.
• Measure size. Very large flight feathers (25-35 cm) fit this bulky seabird, among the largest petrel-type feathers you'll encounter.
• Rule out an all-white or heavily white-mottled feather — that pattern instead suggests the related Southern Giant Petrel's white morph.
• Feel the texture. Dense, somewhat oily-feeling feathers are consistent with this pelagic species' rough-water lifestyle.
• Check for a lack of strong pattern. Giant petrel feathers are largely unpatterned mottled brown-gray, unlike more boldly marked seabirds.
• Consider location: Southern Ocean waters, subantarctic islands, or beaches in that region support this ID.

Similar Species & How to Tell Them Apart

Southern Giant Petrel is the closest look-alike and, in its dark morph, is essentially identical in feather appearance, the two are very difficult to separate by feather alone, and the presence of a true white morph individual (all-white or heavily white-speckled) would point specifically to Southern rather than Northern Giant Petrel, since Northern lacks that morph entirely. Wandering Albatross and other large albatrosses are considerably larger still, with flight feathers that can exceed the giant petrel's, and mature albatrosses show much more white in the body plumage than a giant petrel ever does. Sooty Albatross, smaller and more slender, has more uniformly sooty-brown feathers without the giant petrel's paler head tendency. Overall bulk and the dark brownish-gray, paler-headed pattern (with no white-morph possibility) are the best clues for Northern Giant Petrel specifically.

Where & When You'll Find Them

Northern Giant Petrels breed on subantarctic islands (including islands around New Zealand, and various South Atlantic and Indian Ocean island groups), ranging widely over the Southern Ocean outside the breeding season and scavenging carrion, including at seal and penguin colonies. Feathers are most likely found near breeding colonies during the austral spring-to-summer nesting season, or washed ashore on beaches in the Southern Ocean region following storms. Molt in adults occurs largely outside the breeding period, so worn feathers found away from colonies could reflect birds molting at sea over an extended period.