Bittern

The bittern (Botaurus stellaris) is a stocky, thickset heron that is best known for its booming call that can carry for a mile or more in spring. It is a bird that is more often heard than seen.

Distribution

The species discussed here is also known as the “Eurasian bittern” or “great bittern”, and is not to be confused with species that are more common in other parts of the world such as the “yellow bittern” or “American bittern”.

The bittern is found throughout Europe except the far north. In Britain it is resident in only a few places, namely wetland reserves in Lancashire, East Anglia and the Thames Estuary. 

It winters in other parts of southern England. It lives in reedbeds next to lakes and rivers.

Appearance

The bittern is 75 centimetres (30 inches) in length. Its plumage is golden brown and buff, being striped and mottled with darker feathers. The crown of the head is dark brown and the throat and underside much lighter. The bill is pale yellow and the legs green. The wings are broad and rounded. Males and females look alike. Younger birds are lighter in colour.

Behaviour

The bittern’s flight is owl-like with leisurely, deep wing beats. The neck is retracted but the legs trail behind.

On the ground, the bittern walks with deliberate, high steps, the head being lowered and the shoulders hunched. It will sometimes stand stock still before taking the next step.

The bittern is well camouflaged against the reeds, and it has a way of making its presence even more difficult to detect. It stretches its neck to the full extent with the bill pointing skywards, but is able to swivel its eyes so that they look forwards at the potential threat. It will also sway from side to side in time with the reeds if a breeze is blowing. It can stay in this upright posture for an hour or more at a time.

Bitterns feed on fish, frogs, tadpoles, insects and larvae.

Breeding

Bitterns arrive at their nesting site in March or April, which is when the males announce their presence with the famous booming call. Male bitterns may attract and mate with several females.

The nest is built in the reeds by the female bittern alone, comprising a flat pile of reed stalks. Five or six eggs are laid and incubated by the female with no help from her partner. The chicks hatch after about 25 days and are fed, again only by the female, with regurgitated food. The chicks are fully fledged at eight weeks old.

Only one brood is raised.

Conservation Status

The bittern has red status in the UK as a bird that is under considerable threat. This is mainly due to loss of the bittern’s very specific habitat. The RSPB (Royal Society for the Protection of Birds) is taking active steps to preserve the species at its wetland reserves at Minsmere (Suffolk) and Leighton Moss (Lancashire).

This page of the RSPB website includes a recording of the booming call, a short video, and much more information.

© John Welford