Eurasian bittern

The Eurasian bittern or great bittern (Botaurus stellaris) is a wading bird in the bittern subfamily (Botaurinae) of the heron family Ardeidae. There are two subspecies, the northern race (B. s. stellaris) breeding in parts of Europe and Asia, as well as on the northern coast of Africa, while the southern race (B. s. capensis) is endemic to parts of southern Africa. It is a secretive bird, seldom seen in the open as it prefers to skulk in reed beds and thick vegetation near water bodies. Its presence is apparent in the spring, when the booming call of the male during the breeding season can be heard. It feeds on fish, small mammals, fledgling birds, amphibians, crustaceans and insects. The nest is usually built among reeds at the edge of bodies of water. The female incubates the clutch of eggs and feeds the young chicks, which leave the nest when about two weeks old. She continues to care for them until they are fully fledged some six weeks later. With its specific habitat requirements and the general reduction in wetlands across its range, the population is thought to be in decline globally. However the decline is slow, and the International Union for Conservation of Nature has assessed its overall conservation status as being of 'least concern'. Nevertheless, some local populations are at risk and the population of the southern race has declined more dramatically and is cause for concern. In the United Kingdom it is one of the most threatened of all bird species. This species was first described as Ardea stellaris botaurus as early as the 1660's by the ornithologist Thomas Browne and as Ardea stellaris by the Swedish naturalist Carl Linnaeus in his Systema Naturae of 1758. It is placed in the subfamily Botaurinae, and its closest relatives are the American bittern (Botaurus lentiginosus), the pinnated bittern (Botaurus pinnatus) and the Australasian bittern (Botaurus poiciloptilus). Two races of Eurasian bittern are recognised; the nominate subspecies B. s. stellaris has a palearctic distribution and occurs across a broad swathe of Europe, North Africa and Asia, while the other subspecies, B. s. capensis, occurs only in southern Africa. The name capensis was used for species found in the Afrotropics for which no exact range was known. The generic name Botaurus was given by the English naturalist James Francis Stephens, and is derived from Medieval Latin butaurus, 'bittern', itself constructed from the Middle English name for the bird, botor. Pliny gave a fanciful derivation from Bos (ox) and taurus (bull), because the bittern's call resembles the bellowing of a bull. The species name stellaris is Latin for 'starred', from stella, 'star', and refers to the speckled plumage. Its folk names, often local, include many variations on the themes of 'barrel-maker', 'bog-bull', 'bog hen', 'bog-trotter', 'bog-bumper', 'mire drum', 'butter bump', 'bitter bum', 'bog blutter', 'bog drum', 'boom bird', 'bottle-bump', 'bull of the bog', 'bull of the mire', 'bumpy cors', and 'heather blutter'. Most of these were onomatopoeic colloquial names for the bird; the call was described as 'bumping' or 'booming'. Mire and bog denote the bird's habitat. Bitterns are thickset herons with bright, pale, buffy-brown plumage covered with dark streaks and bars As its alternate name suggests, this species is the largest of the bitterns, with males being rather larger than females. The Eurasian or great bittern is 69–81 cm (27–32 in) in length, with a 100–130 cm (39–51 in) wingspan and a body mass of 0.87–1.94 kg (1.9–4.3 lb). The crown and nape are black, with the individual feathers rather long and loosely arranged, tipped with buff narrowly barred with black. The sides of the head and neck are a more uniform tawny-buff, irregularly barred with black. The mantle, scapulars and back are of a similar colour but are more heavily barred, the individual feathers having black centres and barring. The head has a yellowish-buff superciliary stripe and a brownish-black moustachial stripe. The sides of the neck are a rusty-brown with faint barring. The chin and throat are buff, the central feathers on the throat having longitudinal stripes of rusty-brown. The breast and belly are yellowish-buff, with broad stripes of brown at the side and narrow stripes in the centre. The tail is rusty-buff with black streaks in the centre and black mottling near the edge. The wings are pale rusty-brown irregularly barred, streaked and mottled with black. The plumage has a loose texture, and elongated feathers on the crown, neck and breast can be erected. The powerful bill is greenish-yellow with a darker tip to the upper mandible. The eye has a yellow iris and is surrounded by a ring of greenish or bluish bare skin. The legs and feet are greenish, with some yellow on the tarsal joint and yellow soles to the feet. Juveniles have similar plumage to adults but are somewhat paler with less distinct markings.