In Birds
In the northern hemisphere, adult birds (possibly inexperienced younger adults) of many species are known to continue past their normal breeding range during their spring migration and end up in areas further north (such birds are termed spring overshoots.)
In autumn, some young birds, instead of heading to their usual wintering grounds, take "incorrect" courses and migrate through areas which are not on their normal migration path. For example Siberian passerines which normally winter in Southeast Asia are commonly found in Northwest Europe, e.g. Arctic Warblers in Britain. This is reverse migration, where the birds migrate in the opposite direction to that expected (say, flying north-west instead of south-east). The causes of this are unknown, but genetic mutation or other anomalies relating to the bird's magnetic sensibilities is suspected.
Other birds are sent off course by storms, such as North American birds, blown across the Atlantic Ocean to Europe. Birds can also be blown out to sea, become physically exhausted, land on a ship and end up being carried across the ocean.
Read more about this topic: Vagrancy (biology)
Famous quotes containing the word birds:
“These beginnings of commerce on a lake in the wilderness are very interesting,—these larger white birds that come to keep company with the gulls.”
—Henry David Thoreau (1817–1862)
“Chaucer is fresh and modern still, and no dust settles on his true passages. It lightens along the line, and we are reminded that flowers have bloomed, and birds sung, and hearts beaten in England. Before the earnest gaze of the reader, the rust and moss of time gradually drop off, and the original green life is revealed. He was a homely and domestic man, and did breathe quite as modern men do.”
—Henry David Thoreau (1817–1862)