The Eurasian Bittern measures 80 cm in length and 125-135 cm in wingspan. It is brown with darker patches and stripes. Its belly is lighter. The top of its head and the feathers between its eyes and bill are black-brown. There is no sexual dimorphism. The young ones have lighter plumage with white patches and stripes. Its longevity is 11 years.
Distribution and Habitat
The Eurasian Bittern is a Heron that inhabits swamps with slowly flowing or stagnant water, with dense swamp plants and coastal bushes, the coasts and frequently flooded areas of rivers, lakes and other water areas. It is found throughout Europe, Asia, and Africa. In Bulgaria it breeds mainly in the swamps near the Danube river and in several interior and coastal water basins- the Dragoman marsh, breeding pond “Hadzhidimitrovo”, Shabla lake and Durankulak Lake, and others. In 2013 it was reported the species nested again in the Burgas lakes. The Eurasian Bittern is registered as nesting in Vaya lake and it is also possible it nests in protected area Poda and Uzungeren.
The Eurasian Bittern is a migratory bird that flies back in March and flies away in September – October. It winters in Greece, Turkey, South and East Asia, Africa. Some individuals stay in Bulgaria (in Dragoman marsh and Aldomirovtsi marsh). The Eurasian Bittern often stays in the Burgas lakes and groups of more than five individuals can be monitored.
The Eurasian Bittern is a night bird. During the day it hides in the dense swamp plants and it gets out in search of food after sunset. When it approaches an enemy, it stands motionless in the reed, raises its body upwards and stretches its neck. In that way it blends with the reed color and it is difficult to be seen.
The Eurasian Bittern searches its food in the water. It feeds on fish, frogs, tadpoles, snails, and crustacean. Sometimes it preys on mice and little water rats that it catches at the coasts. It can also attack small swamp birds that are not good flyers.
The breeding period of the Eurasian Bittern starts in April. The male gives calls that sound like bellowing of a bull. It is a polygamous species- a male can have up to five females. The nest is built on dry reed and sedge in the water. It is laid with leaves. The Eurasian Bittern lays 5 to 6 green-brown eggs which the female incubates for 21-23 days. The male also takes part in feeding the chicks. After raising the chicks the family breaks apart.
According to IUCN its status is Least Concern, but in Bulgaria according to the Red Data Book it is Endangered.