|
Continued from Dotterel Courtship Display, Nest and Chicks.
Habitat and Breeding Areas of
the Dotterel
The areas where Dotterells reside are disjunct, with
some distance separating these areas from each other. The Dotterel
is usually an inhabitant of areas northwards of the polar circle and somewhat
high areas of tundra and lichen. It prefers dry areas which are to a large
extent flat and with only meager, low vegetation, which allows the bird
to see over a conderable distance. Areas with isolated vegetationless sections
andinterspersed with stone are particularly preferred. The comparatively
rarity of these habitats in the Eurasian tundra areas partly explains the
way in which the populations are very much split up.
As well as Scotland, and in the Scandinavian tundra
areas, the European breeding places are in high-altitudes in the alps in
the Graubunden confederation of Switzerland at approximately 2600 meters,
as well as in Austria where breeding populations exist irregularly on the
Zirbitzkogel at approximately 2200 meters in the state of Styria, and in
some mountain areas in the state of Carinthia. In Central Europe the Dotterel
prefers mountains with gentle slopes and wide plateaus, which have a scanty
overgrowth of Alpine Sedge Mat (Caricetum curvulae). In the Abruzzo
region of Central Italy the Dottererl's habitat consists of nearly vegetationless
chalky rubble with only occasional isolated islands of vegetation.
The population of Dotterels in Abruzzo National Park is however very small
in number. In some mountain regions of Europe the Dotterel occurs
in extremely small individual numbers and unfortunately it no longer breeds
regularly in these European mountains.
Completely deviating from this habitat type, Geographically
completely isolated broods occurred in low-lying "polder" areas in
the IJsselmeer lake in the Netherlands from 1961 to 1969. These polder
areas in the Netherlands were used intensively for agriculture, making
such broods of dotterels quite surprising. At the polar circle this
species breeds near the sea level, but in central Asia at hights of over
3500 meters.
The Dotterel occurs in the northern part of the
Urals mountains, on the Kola peninisula and in the southern part of Novaya
Zemlya in Northern Russia. A large, closed migration area lies in the Altay
Mountains in Central Asia, and their Eastern foothills; it stretches top
the south and Northeast of Lake Baikal which is the oldest and deepest
lake in the world. In Siberia, between the mouth of the River Ob and that
of the River Lena the Dotterel seems to occur only very rarely or to be
missing completely. The data about this area is anyhow partly contradictory.
Only east of the River Lena begin again large, occurrences of the Dotterel,
which reach eastward in Anadyr and southeastward in a broadly protruding
finger of land into the Verkhoyansk Range of mountains and up to the central
area of the Kolyma River. Again isolated from these occurrences the Dotterel
probaly breeds on the Chukchi peninsula and on some Siberian islands as
well as on the Taymyr peninsula.
Whether the Dotterel still occasionally breeds
in to the Vosges mountains, or in the High Tatra mountains, as well as
in the Karkonosze mountains is not well-known. Observations of broods
and are however reported from these areas. It is also unclear whether
the species is still a breeding bird in the Pyreneeses or in the Carpathian
Mountains as well as in some places of north Greece, and how large is the
number of pairs breeding in these places.
Migration
All Dotterel populations are migratory, with a relatively
small wintering area compared to the bird's enormous areas of population
in the breeding season. The most substantial wintering areas for
the majority of the European birds lie in northwest Africa, in particular
in the Atlas area. The asiatic populations visit the Sinai peninsula, as
well as in Iraq and Iran. By at the end of of July the breeding areas are
vacated, the females taking off about 3 weeks before the males and young
birds. The migration takes place on traditional migration routes
in a broad front, usually in small troops or groups of from 20 to 30 individuals.
Many of the European birds seem to reach their winter accomodation in a
non-stop flight. The East Asian birds travel a distance of up to 10,000
kilometers on their migration.
The home migration begins in the middle of February.
By the middle of March all Dotterels have left their wintering area. The
bird's arrival back in the breeding areas starts from at the end of of
April.
|
