Bittern

What does a Bittern look like?

Bitterns are wading birds part of the bittern subfamily. Adults have a bright, buff-brown plumage that has a mixture of barring and striping all over. They have black caps, and necks are buffed brown with the chin and throat a creamy-white mixed with brown streaks. Under the wing are a mottled grey and light buff colour. The legs and feet are a pale grey with yellow soles. The bill is yellow, with ridges of brown and the tip darker. Both male and females look similar, but males are generally larger in all measurements. Their plumage can be variable, though, with some bitterns being darker or paler. Females can also be less well marked.

Juveniles look mostly similar to the adults but will have a paler cap, and the moustache will also be paler.

Great bittern in flight (eurasian bittern)

What does a Bittern sound like?

The call of the male bittern is extremely impressive. They will produce a booming sound that is used for defending their territories and for attracting a mate during the breeding season. This booming sound can be heard up to 3 miles away (5 km). The booming call comprises between two and four notes, and can be rendered as “up, up, up, rumb”. Females will often respond to this call with a "wumph" call.

The booming sound often compared to someone blowing over the mouth of an empty milk bottle.

What does a Bittern eat?

Bitterns have a varied diet, which is determined by the season and where they are located. However, their diets mostly comprise a wide variety of fish, amphibians and insects and their larvae.

Where can I see Bitterns?

Bitterns can be seen all around the year in the UK, there is a small breeding population, but winter is generally the best time to see them. Wetland areas with large reedbeds are usually good spots.

Close up of a great bittern (eurasian bittern)

Signs and Spotting tips

Bitterns are extremely secretive and usually spend most of the time on their own, hidden away in dense reedbeds. They are masters of camouflage.

Becoming familiar with the booming sound can be one of the best ways to tell that you're in close proximity to a bittern. You'll need to make sure that you go to a nature reserve with large reedbeds for your best chance.

How does a Bittern breed?

Bitterns are often polygamous, with the male mating with up to five females, but this is not always the case as there are monogamy reports. The nests are constructed by females in dense reedbeds, usually on a mat of dead plants. Females will usually lay between 4-5 olive-brown eggs that are laid in 3-day intervals. Incubation lasts around 25 days. Most of the time, females will solely feed and raise the chicks alone.

Bitterns nest with eggs

How long do Bitterns live for?

The average lifespan for a bittern is around 4 years, with the oldest recorded age of over 11 years.