Eurasian Bittern

Bittern

The bittern ( Botaurus stellaris ) is a wading bird in the heron family ( Ardeidae ). The subspecies stellaris stellaris botaurus occurs in Eurasia, while the subspecies botaurus stellaris capensis is a breeding bird in South Africa. As defined in the Little Bittern it is also sometimes referred to as " Bittern ". The bittern lives hidden in extensive reedbeds.

Features

Bitterns reach a height of 70 to 80 centimeters. The females weigh 817-1150, the males 966-1940 grams. Males are not only strikingly larger than females, they are also somewhat more marked than the females. The plumage dress also has geographical variations. So bitterns are in East Asia drawn somewhat more prominent and long time have therefore been classified as a subspecies.

The bittern is slightly larger than a domestic chicken and stout figure with short, thick neck and short legs, a relatively short, strong green - yellow beak ( at the top with finely serrated cutting horn ). The plumage is finely black, tan and white stripes. Chin and throat are creamy white and have a reddish- brown longitudinal stripe in the middle.

The appearance and behavior of the bittern is unremarkable. With their plumage is decorated in warm shades of brown, heavily spotted she is very well camouflaged in Altschilf. The plumage mimicking a pattern of light and shadow, which dissolves the contours of the bird itself behind a few reeds. This form of camouflage is called Somatolyse. As one approaches the bittern, it takes up to a small distance, the so-called pole position: with upwardly directed head and beak the bittern varies as the reeds surrounding it in the wind, their longitudinal stripes act as individual straws. This behavior already show young Bitterns, which are not yet fledged.

Voice

In spring the males give dull mating calls of himself that are miles to hear and the bittern have formerly popular names " Moorochse ", " water ox ", " Riedochse " or " Mooskuh " is entered.

Distribution area

The range of the subspecies stellaris stellaris botaurus covers Great Britain via Sweden, Finland, Germany, Lithuania, Italy, European Russia to the north of Morocco and Algeria. This subspecies is also found in Albania, Bulgaria, Turkey, northern Iran, Kazakhstan, Azerbaijan, Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Afghanistan, Mongolia, North China, Siberia, Japan, and North and South Korea. The subspecies capensis breeds in the South African province of Natal and Transval. Probably the kind in Zambia a breeding bird.

The bittern is a partial migrant. A number of bitterns remain in their breeding grounds if the water does not freeze or migrate only slightly more favored climates. Some populations, such as in England and the Netherlands are almost exclusively non-migratory birds. Populations wintering in Central Europe, Eastern Europe to the Ukraine, to the east of Saudi Arabia, Iraq, Iran, Turkmenistan, Pakistan, northern India, Nepal, Bangladesh, the Southeast of China, southern Thailand, northern Malaysia as well as in Libya, Egypt and Africa south of the Sahara. The wintering area there extends from Mauritania, Senegal, Ghana, Gambia, Gabon, Nigeria, Cameroon, Kenya, Nordzaire, Sudan, Ethiopia and Eritrea.

Habitat

The bittern prefers to live in extensive siltation zones of lakes, oxbow lakes and ponds. Particularly important are well preserved, extensive reeds and reed stocks, in which the birds around-climb sent, in which they can build their nests and find shelter.

The bittern needed to foraging interspersed low vegetation, such as Ditches, riparian areas and open water bodies. During the breeding season they defend their feeding and breeding grounds energetic. It even comes to attacks in the air. Outside the breeding season you can watch bitterns in larger groups.

Food and foraging

The food spectrum of the bittern is very large. They feed mainly on small fish, frogs and amphibians and aquatic insects. They also eat smaller mammals such as mice and small birds and Family rob the nests of ducks birds.

Behavior and migration

The bittern is nocturnal and therefore difficult to observe during the day. Young bitterns stripes (how many herons ) far and wide, while many of the European breeding birds spend the winter in their breeding range, giving them in severe winters often disastrous. However, a large part pulls in winter to western and southern Europe or up to tropical Africa.

Reproduction and breeding

The males are polygamous and mate to where the stocks are large enough, with several females. Do not participate in the business of breeding or rearing. The young are altricial and come up with about two months to fly. According to the rules of the nest squatting types bitterns supposed to be monogamous. But we know of male bitterns with three to five, even up to seven breeding females, their nests are arranged in a star shape around their territory. The nest, reeds and sedges is padded with leaves and dry grass.

After 25-26 days the brown slip bedunten altricial. Even after 8 days they take grave danger, " Standing Stance " a; they leave the nest usually at the age of 4 to 5 weeks ( but often after only 2-3 weeks) and then roam around in the neighborhood, until they are completely independent and capable of flying at 8 weeks.

Population trends in Central Europe and threat

The bittern comes from North Africa across the temperate latitudes of Europe to East Asia before. The European distribution area we find in the vast swamplands of Eastern Europe. In Poland hatched in the years 2002/2003 4100-4800 breeding pairs. Larger bittern deposits are found at Lake Neusiedl in Austria as well as in the Mecklenburg Lake District. In the German states of Hesse and Baden- Württemberg, has disappeared as a regular breeding bird. In Bavaria and North Rhine -Westphalia there are only a few single pairs.

Due to loss of their habitat, in particular the destruction of reed beds or drainage, the bittern is endangered. Many waters also leisure activities have disastrous impact on the stock, as bitterns are extremely susceptible to interference. However, they also suffer from drainage and groundwater depletion, as they occur for example in the context of land consolidation and intensification of agriculture. There are also natural stock fluctuations: In severe winters individual populations can be wiped out completely. Despite this sensitivity to cold winters, the bittern is one of the types that do not benefit according to estimates by ornithologists of climate warming. Projections based on climate models assume that the bittern their range further shifted to the end of the 21st century to the northeast. In the South, West and Central Europe, the stocks will decline it.

The bittern is in Germany on the red list of endangered species and is strictly protected by Federal Nature Conservation Act, BArtSchV. 610 breeding pairs counted - Here in 2005 were about 580.

The bittern in the literature

In Arthur Conan Doyle's Sherlock Holmes novel The Hound of the Baskervilles Dr. Watson and Mr. Stapleton hear from the bog an inexplicable rage. As the naturalist Stapleton does not believe in the ghost dog, he thinks it could be a bittern.

At the beginning of the third part of Søren Kierkegaard's Stages on the way life is the bittern from the Soeborg - Sø that calls four times, called secret voice of loneliness. The whimsical bird have only one wish that he stay lonely.

In Eichendorff's work " From the Life of a ne'er-do " describes the narrator in the first chapter that he sits like a pelican in the reeds of a pond in the garden.