Drift migration is the phenomenon in which
migrating bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s are blown off course by the winds while they are in flight. It is more likely to happen to birds heading south in autumn because the large numbers of inexperienced young birds are less able to compensate than the adults heading north in spring.
Drift is assisted by disorientating conditions such as mist or drizzle, and can result in large numbers of birds arriving together in an area in which they are not normally seen. In the UK this is called a fall, while in the U.S. it is known as a fallout, though in the latter case, it need not involve vagrant birds.
An example would be an east wind in September blowing
Scandinavia
Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...
n migrants such as
bluethroat
The bluethroat (''Luscinia svecica'') is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Muscicapidae. It, and similar small Europea ...
s,
wryneck
The wrynecks (genus ''Jynx'') are a small but distinctive group of small Old World woodpeckers. ''Jynx'' is from the Ancient Greek ''iunx'', the Eurasian wryneck.
These birds get their English name from their ability to turn their heads almos ...
s, and the continental race of
robin onto the east coast of
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
and
Scotland
Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...
, leading to temporary concentrations of these species at headlands like
Spurn
Spurn is a narrow sand tidal island located off the tip of the coast of the East Riding of Yorkshire, England that reaches into the North Sea and forms the north bank of the mouth of the Humber Estuary. It was a spit with a semi-permanent con ...
.
See also
*
Reverse migration (birds)
Reverse migration also called reverse misorientation is a phenomenon in bird migration where a bird flies in the opposite direction of what is typical of its species during the spring or autumn migration.
If a bird sets off in the opposite directi ...
References
{{DEFAULTSORT:Drift Migration
Bird migration