The Eurasian Bittern (Botaurus stellaris) is one of Sweden's most secretive breeding birds, a heron-sized bird of the reedbeds that is heard far more often than seen. At 69-81 cm long with a wingspan of 100-130 cm, it is nearly as large as a Grey Heron, but its intensely golden-brown plumage, densely patterned with dark streaks and bars, gives it exceptional camouflage against dry reed stems. When threatened it freezes with neck stretched straight up and bill pointed skyward, swaying gently with the wind so that its streaked plumage merges almost perfectly with the surrounding reeds.
The male's booming call is unmistakable: a deep, pumping "umb-umb-umb" delivered in series of two to five booms that can carry three to five kilometres in calm weather, produced using air sacs that act as a resonance chamber. It is heard from early spring to midsummer, mostly at dawn and dusk, and is usually the first sign that a bittern is present at all. Eurasian Bitterns breed in southern and central Sweden, most strongly around Mälardalen, in Skåne's coastal lakes and in Blekinge, requiring large, continuous reedbeds with adjacent deep water; small, isolated wetlands are avoided. The nest, a platform of trodden-down reed built directly on the water within the reed bed, holds 4-6 eggs incubated and tended by the female alone, since the male is polygynous and takes no part in chick-rearing. Hunting mainly at night and dawn by standing motionless at the water's edge before striking with lightning speed, it feeds chiefly on fish, frogs and newts, supplemented by large insects, crustaceans and occasionally small mammals or birds. With 500-800 pairs, the Swedish population is stable and classed as Near Threatened, while the species remains globally secure.
Read about this species in Swedish →