What is "gadfly petrel"

Gadfly \Gad"fly`\ (g[a^]d"fl[imac]`), n.; pl. Gadflies. [Gad + fly.] (Zo["o]l.) Any dipterous insect of the genus Oestrus, and allied genera of botflies.

Note: The sheep gadfly ( Oestrus ovis) deposits its young in the nostrils of sheep, and the larv[ae] develop in the frontal sinuses. The common species which infests cattle ( Hypoderma bovis) deposits its eggs upon or in the skin where the larv[ae] or bots live and produce sores called wormels. The gadflies of the horse produce the intestinal parasites called bots. See Botfly, and Bots. The true horseflies are often erroneously called gadflies, and the true gadflies are sometimes incorrectly called breeze flies.

Gadfly petrel (Zo["o]l.), one of several small petrels of the genus Oestrelata.

n. Any of the petrels of the genus ''Pterodroma''.

The gadfly petrels are seabirds in the bird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading horseflies. The flight action is also reflected in the genus name Pterodroma, from Ancient Greek pteron, "wing" and dromos, "runner".

These medium to large petrels feed on food items picked from the ocean surface.

The short, sturdy bills of the Pterodroma'' species in this group, about 35 altogether, are adapted for soft prey taken at the surface; they have twisted intestines for digesting marine animals which have unusual biochemistries.

Their complex wing and face marking are probably for interspecific recognition.

These birds nest in colonies on islands and are pelagic when not breeding. One white egg is laid usually in a burrow or on open ground. They are nocturnal at the breeding colonies.

While generally wide-ranging, most Pterodroma species are confined to a single ocean basin (e.g. Atlantic), and vagrancy is not as common amongst Pterodromas as it is in some other seabird species (c.f. the Storm-Petrels Hydrobatidae).