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Petrels and Shearwaters

Adaptations



Birds that spend most of their life flying over vast, windy stretches of ocean must have a variety of ways for dealing with the stresses and demands of such an existence, and petrels and shearwaters are remarkable in their adaptations. Most species have long narrow wings designed for gliding and soaring, while some of the smaller diving petrels have short stubby wings that work well in the underwater pursuit of fish. To watch these graceful birds "shearing" the wavetops with their stiff-winged, seemingly effortless flight, is to witness a true natural wonder.



Characteristic tubular nostrils located on top of the bill serve as a means of expelling saline solution from their large salt glands, located internally near the eye sockets. The salt glands allow these birds to drink sea-water without any harmful effects, since their kidneys cannot produce a concentrated urine. The horny structure of the exterior nostrils protects the internal nasal passageway from the irritating salt spray, and also serves as an opening to their very efficient olfactory organs. Petrels and shearwaters have an excellent sense of smell, which they use to find food, burrows, and other birds of their species.

These seabirds have oily, waterproof feathers and a dense undercoat of insulating down. Their webbed feet help them swim, and are also used, especially by the storm petrels, to patter upon the ocean surface in search of floating bits of food.

The strong bill has a food-grabbing hook on the end, and the typical dark, or dark-and-light plumage helps them blend into a monochromatic landscape.

The petrels and shearwaters have a characteristic musky odor arising from their stomach oils, which are used as a food for the young, as a defensive weapon (squirted when needed), and as additional waterproofing for their feathers.



Additional topics

Science EncyclopediaScience & Philosophy: Pebi- to History of Philosophy - IndifferentismPetrels and Shearwaters - Distribution, Life History, Adaptations, Conservation - Food