Their straight, deeply grooved bills with hooked tips have one or two tubes enclosing their nostrils. The beaks consist of several plates. Their hind toes are either nonexistent or underdeveloped, their feet are webbed, and they have long, narrow wings. Their adult plumage is primarily black, white, and gray. They have a characteristic powerful musky odor.

ECOLOGY & HABITAT

Open seas, coming into land to only breed.

DIET

For most species, fish, squid, krill, and other marine zooplankton are staples of their diet. Some of them also eat carrion (dead birds, whales and other cetaceans).

REPRODUCTION

All of them are colonial, predominantly breeding on offshore or oceanic islands. They are monogamous breeders and form long-term pair bonds. These pair bonds take several years to develop in some species.

REFERENCES

del Hoyo, J., Elliott, A., Sargatal, J., Christie, D. A. (2010). Handbook of the Birds of the World Series. Lynx Edicions.

Lovette, I. J., Fitzpatrick, J. W. (2016). Handbook of Bird Biology. Wiley-Blackwell.

Gill, F. B., Prum, R. O. (2019). Ornithology. W.H. Freeman & Co. Ltd.