Eurasian Bittern

The Eurasian bittern, or great bittern (Botaurus stellaris), is a wading bird belonging to the heron family Ardeidae, within the bittern subfamily Botaurinae. It is the largest of the bitterns, with males slightly surpassing females in size. The plumage is a bright, pale, buffy-brown, adorned with dark streaks and bars. The bird's crown and nape are black, tipped with buff and barred with black, while the sides of the head and neck are a more uniform tawny-buff with irregular black barring. The bill is greenish-yellow, the eyes are surrounded by a ring of greenish or bluish bare skin, and the legs and feet are greenish with some yellow.

Identification Tips

The Eurasian bittern can be identified by its thickset heron-like appearance, buffy-brown plumage with dark streaks and bars, and a yellowish-buff superciliary stripe. The elongated feathers on the crown, neck, and breast can be erected, and the bird has a powerful greenish-yellow bill with a darker upper mandible tip. Juveniles resemble adults but are paler with less distinct markings.

Habitat

This species typically inhabits reed beds and swamps, as well as lakes, lagoons, and sluggish rivers fringed by rank vegetation. It sometimes nests by ponds in agricultural areas and prefers large reed beds for breeding.

Distribution

The Eurasian bittern has a broad range, with the northern race (B. s. stellaris) breeding in parts of Europe, across the Palearctic, and on the northern coast of Africa. The southern race (B. s. capensis) is endemic to parts of southern Africa. Some populations are sedentary, while others migrate to warmer regions during colder months.

Behaviour

The Eurasian bittern is a solitary and secretive bird, often skulking in reed beds and thick vegetation. It adopts a defensive pose with elongated feathers spread, and when threatened, it may freeze with its bill pointed upwards, blending into the reeds. It is most active at dawn and dusk and forages by walking stealthily or remaining still above water.

Song & Calls

The male's mating call is a deep, sighing fog-horn or bull-like boom, audible from a distance of up to five kilometers on a calm night. This booming call is mainly given between January and April during the breeding season.

Breeding

Males are polygamous, mating with multiple females. The nest is an untidy platform built among reeds by the female, who also incubates the eggs and feeds the young. Chicks leave the nest after about two weeks and are fully fledged around six weeks later.

Similar Species

The Eurasian bittern can be confused with other heron species, but its larger size, distinctive booming call, and habitat preferences help differentiate it.

Diet and Feeding

The diet includes fish, small mammals, fledgling birds, amphibians, crustaceans, and insects. The bittern hunts along the reed margins in shallow water and may consume some vegetable matter such as aquatic plants.

Conservation status

The Eurasian bittern is classified as "Least Concern" by the IUCN, with a wide range and a large population. However, the population is thought to be in decline due to habitat destruction, and some local populations are at risk. The southern race has declined more dramatically and is of conservation concern.