Bitterns are secretive birds, which inhabit dense vegetation in freshwater swamps. They are rarely seen and their presence is often only detected from their call. As its name suggests, the little bittern is a tiny species, standing only 20 cm tall. There has been a single New Zealand record, of a juvenile at Westport in 1987. Vagrants may occur more frequently than the single sighting suggests, but would most likely be overlooked.

Identification

Little bitterns are small herons standing about 20 cm tall. Adult males are distinctive with a black cap, back and tail and yellowish-buff brown plumage on the neck, under parts and patches on the wings. The bill is yellowish-brown and leg colour is variable from greenish to yellow. In contrast, the female is smaller and darker; its neck, back and wings are rufous-brown, its wing patches a paler rufous and its black crest less developed than the male. The under parts are striped in brown. In both sexes, the neck has whitish longitudinal streaks and the lower breast is plumed and can be flared during threat displays. The entire juvenile plumage is strongly streaked chestnut-brown with mottled brown and buff wing patches.

Voice: a harsh ‘koh’ when flushed, a deep, repeated barking ‘koh’ in the breeding season and ‘kwer’ during flight.

Similar species: the extinct New Zealand little bittern (I. novaezelandiae) was larger, rich chestnut on the back, and more striped ventrally. The very similar yellow bittern (I. sinensis) from south-east Asia has no black on the back, and a longer, slimmer bill.

Distribution and habitat

Widely distributed throughout western Europe, the Ukraine, parts of Russia and as far as India, central and southern Africa and Madagascar and south and eastern Australia and southern New Guinea. Little bitterns inhabit a wide variety of wetland vegetation types and water bodies, including bogs, ponds, reed fringed margins of lakes and dense swamps.

New Zealand records

A single record of a live juvenile, at Westport in February 1987. The bird was tired and thin and so was fed by a local wildlife carer before being released in Birchfield swamp north of Westport three weeks later.

Behaviour and ecology

Little bitterns are secretive and inconspicuous although not necessarily shy of humans. They are migratory across most of their breeding range. They disperse widely after breeding finishes, flying singly and in small groups at night. For example, birds from Europe cross the Mediterranean into Africa.

Food

The Westport bird fed readily on tadpoles, bullies and freshwater invertebrates.

Weblinks

BirdLife factsheet

https://www.heronconservation.org/?s=bittern

References

Marchant, S.; Higgins, P. J. (eds) 1990. Handbook of Australian, New Zealand and Antarctic birds. Vol. 1,: ratites to ducks. Melbourne, Oxford University Press.

O'Donnell, C.F.J.; Dilks, P.J. 1988. First record of the Australian little bittern (Ixobrychus minutus) in New Zealand. Notornis 35: 153-157.

Recommended citation

O’Donnell, C.F.J. 2013 [updated 2022]. Little bittern. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz