Editing Eurasian bittern (section)

==Behaviour==
[[File:Große Rohrdommel, Botaurus stellaris 1b.JPG|thumb|upright|left|In defensive pose with elongated feathers spread]]
Usually solitary, the Eurasian bittern forages in reed beds, walking stealthily or remaining still above a body of water where prey may occur. It is a shy bird, and if disturbed, often points its bill directly upwards and freezes in that position, causing its [[Crypsis|cryptic]] plumage to blend into the surrounding reeds, an action known as ''bitterning''. While in this position, the shield of elongated feathers on throat and breast droop downwards and hide the neck, so that the outline of the head and body is obscured. Sometimes it resorts to applying [[Down feather#Powder down|powder down]] produced by patches of specialist [[down feather]]s at the side of its breast. This white dusty material seems to help it to rid its head and neck of slime after feeding on [[eel]]s. It then removes the excess powder by scratching vigorously before applying [[Uropygial gland#Gland secretion|preen oil]] from the [[Uropygial gland|gland]] at the base of its tail.<ref name=Witherby/>

The bird has a secretive nature, keeping largely hidden in the reeds and coarse vegetation. Occasionally, especially in hard winter weather, it stands in the open beside the water's edge, although usually close to cover to facilitate a hasty retreat. In flight, its wings can be seen to be broad and rounded, and its legs trail behind it in typical heron fashion. Its neck is extended when it takes off, but is retracted when it has picked up speed. It seldom flies however, except when feeding young, preferring to move through the vegetation stealthily on foot. Its gait is slow and deliberate and it can clamber over reeds by gripping several at a time with its toes. It is most active at dawn and dusk, but also sometimes forages by day.<ref name=Witherby/>

[[File:Roerdomp vissend in slootje-4961939.webm|thumb|right|fishing]]
[[File:Botaurus stellaris MWNH 0909.JPG|thumb|Eggs, Collection [[Museum Wiesbaden]]. Ruler is marked in millimeters.]]
Eurasian bitterns feed on fish, small mammals, amphibians and invertebrates, hunting along the reed margins in shallow water. British records include eels up to {{convert|35|cm|in|0|abbr=on}} and other fish, mice and voles, small birds and fledglings, frogs, newts, crabs, shrimps, molluscs, spiders and insects. In continental Europe, members of over twenty families of beetle are eaten, as well as [[Dragonfly|dragonflies]], [[bee]]s, [[grasshopper]]s and [[earwig]]s. Some vegetable matter such as aquatic plants is also consumed.<ref name=Witherby/>

Males are polygamous, mating with up to five females. The nest is built in the previous year's standing reeds and consists of an untidy platform some {{convert|30|cm|in|0|abbr=on}} across. It may be on a tussock surrounded by water or on matted roots close to water and is built by the female using bits of reed, sedges and grass stalks, with a lining of finer fragments. The eggs average {{convert|50|by|40|mm|in|frac=2|abbr=on}} in size and are non-glossy, olive-brown, with some darker speckling at the broader end. Four to six eggs are laid in late March and April and incubated by the female for about twenty-six days. After hatching, the chicks spend about two weeks in the nest before leaving to swim amongst the reeds. The female rears them without help from the male, regurgitating food into the nest from her crop, the young seizing her bill and pulling it down. They become fully fledged at about eight weeks.<ref name=Witherby/>

===Voice===
[[File:Botaurus stellaris - Eurasian Bittern XC362697.mp3|thumb|right|Male booming]]
The [[mating call]] or contact call of the male is a deep, sighing [[fog-horn]] or bull-like ''boom'' with a quick rise and an only slightly longer fall, easily audible from a distance of {{convert|3|mi|km|0|abbr=off|order=flip|spell=on}} on a calm night. The call is mainly given between January and April during the mating season. Surveys of Eurasian bitterns are carried out by noting the number of distinct male booms in a given area. Prior to modern science, it was unknown how such a small bird produced a call so low-pitched: common explanations included that the bird made its call into a straw or that it blew directly into the water. It is now known that the sound is produced by expelling air from the [[Esophagus|oesophagus]] with the aid of powerful muscles surrounding it.<ref name=BBCRadio4/>