Bittern

The Bittern (Botaurus stellaris) is a wading bird of the heron family.

Description[]

Bitterns are thickset herons with bright, pale, buffy-brown plumage covered with dark streaks and bars. The Eurasian or Great Bittern is 69-81 cm (24"-34") in length, with a 100-130 cm wingspan, although their most distinctive feature is the males booming call in spring.

They often stand still for long periods in reedbeds, they're streaked plumage making them hard to spot through the reeds which they blend in perfectly with.

Diet[]

Bitterns feed on fish, eels, amphibians and invertebrates, hunting along the reed margins in shallow water.

Breeding[]

Males are polygamous with each mating with up to five females. The nest is built in the previous year's standing reeds and consists of a platform some 30 cm across. Four or five eggs are laid in late March and April and incubated by the female bird. After hatching, the chicks spend about two weeks in the nest and then disperse amongst the reeds.

Distribution[]

It is declining in much of its temperate European and Asian range. It is resident in the milder west and south, but migrates south from areas where the water freezes in winter.

In the UK, the main areas are Lancashire and East Anglia with an estimated 44 breeding pairs. Europe as a whole is estimated at 20-44,000 males.

Behaviour[]

This bittern is usually well-hidden in Phragmites reedbeds. Usually solitary, it walks stealthily seeking fish, frogs, small mammals and insects. If it senses that it has been seen, it becomes motionless, with its bill pointed upward, causing it to blend into the reeds. It is most active at dawn and dusk.

Its folk names include "barrel-maker", "bog-bull", "bog hen", "bog-trotter", and "butterbump", mire drum, mostly refer to the mating call of the male, which is a deep fog-horn or bull-like boom, easily audible from a distance of 2 miles on a calm night. The Latin for bittern, Botaurus, also refers to the bull. The other part of its scientific name, stellata is the Latin for starry, in reference to its plumage.

Surveys of Eurasian Bitterns are carried out by noting the number of distinct male booms in a given area, these booms can travel for around 5 km.

The Eurasian Bittern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.