Recently established in New Zealand, the nankeen night heron is resident only along the Whanganui River, Manawatu-Wanganui. Elsewhere, it is mostly an infrequent vagrant, although being secretive, pairs may be overlooked. As their name suggests, night herons are largely nocturnal, and are seldom seen during the day unless disturbed from their roost. The nankeen night heron is closely related to the black‑crowned night heron, N. nycticorax, of the Americas, Africa, southern Europe, and Central, South and South-east Asia.

Te Atihaunui a Pāpārangi iwi at Jerusalem (Hiruhārama) consider nankeen night herons to be kaitiaki or caretakers of the remains of one of their tupuna, Hohepa Te Umuroa, who was exiled to Tasmania in 1846, following an incident in the Hutt Valley in which he took part. He died of tuberculosis on Maria Island, Tasmania, the following year and was buried there. In 1988, his remains were repatriated and reburied at Patiarero marae at Hiruhārama. Nankeen night herons were first noticed in Jerusalem soon after, and are considered by local people to have carried Te Umuroa’s spirit back home.

The species’ common name, nankeen, refers to the similarity in colour of its underparts to the yellowish-brown cotton found originally around the Chinese city of Nanking, once used to make buff-coloured cotton trousers.

Identification

A stocky, short-necked heron usually found skulking inside tree canopies, where the birds roost during the daytime. It has a characteristic hunched appearance when perched, making it look broad-shouldered and large-headed. Adults have a dark blue-black crown and hind neck, a narrow burnt-orange line above the eye, rufous-brown upperparts and wings, and a short square rufous-brown tail. The underparts are cream with burnt-orange cheeks, neck and sides of upper breast, seemingly more intensely coloured when breeding. The underwing coverts are beige, and the flight feathers rufous brown. Adult birds also have two or three thin white plumes projecting from the crown down towards the back. These are most obvious in breeding birds but have been seen on adult birds at other times of the year. Some birds in second-year plumage also show white plumes. The bill is black and heavy, about the same length as the head, the top edge curving downwards towards the tip. Bare skin between the eye and bill is pale lime-yellow, and the iris orange, accentuated by a narrow ring of dark feathers around the eye. The legs are normally creamy yellow, but become salmon-red in some breeding individuals. The legs are shorter than other herons in New Zealand, the feet just projecting beyond the tail in flight. Sexes similar but the female is slightly smaller.

Juvenile and immature birds are sandy brown, speckled dark brown, reddish brown and off-white above, and streaked brown below. Juveniles have a brown-streaked crown and nape, in contrast to immature birds, which have a darker, less obviously streaked cap. Flight and tail feathers are chestnut-brown with prominent white tips. Wing coverts are dull reddish brown with white tips, aligned so that they look like serrated bars. The bill is dark grey above grading to olive-yellow below, with a dark grey tip; legs lime-green. The post-juvenile (pre-basic) moult is gradual and prolonged. First-year immatures have a dark crown, which begins to develop when about 6 months old, a useful age-marker. Underparts are still streaked brown on an over off-white base, with the cheeks, neck and upper breast gradually becoming tinged rufous. Upperparts are patterned like juveniles, but also become tinged rufous. Second-year birds are similar to adults except that they still have spotted coverts to varying extents. Transition to full adult plumage apparently complete in the bird’s third year.

Voice: a rasping qu‑arck given by birds departing the roost at night; females and immature birds higher pitched, qu‑ook. A short, deep quock given by roosting birds when disturbed. Chicks in the nest make a rapid, repetitive, high-pitched ticking call, tic-tic-tic-tic-tic… Older chicks and recent fledglings have a deeper begging call, sounding like a distant small dog yapping: yap, yap, yap, yap…

Similar species: Australasian bittern is larger, heavier, and browner, with broadly streaked underparts and finely‑barred underwings. Similar-sized cattle egret is much slimmer and paler; other heron species are considerably larger with longer necks, curved in flight, and longer legs that project well beyond the tail.

Distribution and habitat

Nankeen night herons are resident along the Whanganui River from around Pipiriki to Whanganui where it was first noted in the early 1990s and subsequently found breeding. Birds have been recorded from various sites there almost every year since, in recent years most commonly at Ūpokongaro, where there is a small established breeding colony. Birds are present there throughout the year, with over 570 sightings reported in eBird up to December 2025. Elsewhere in New Zealand it is rare vagrant, recorded on at least 44 occasions between 1845 and 2025, ranging recently from Western Springs Lakeside Park (Auckland) in the north, Raglan (Waikato) in the west, Pōrangahau (Hawkes Bay) in the east, and south to Waitati and Sawyer’s Bay, near Dunedin, and the Snares Islands. The species may have bred at Blenheim in 1958 and, more recently, at Ohakune just outside the Whanganui R catchment, where a recently fledged chick was photographed and a nest found. Three banded birds released from Wellington Zoo in 1982 were subsequently seen separately at Pakawau, Golden Bay (Aug 1983), Waiwhetu Stream, Lower Hutt (Jan 1984), and Warkworth (1984). There is no evidence that these birds or those released near Wellington in 1852 became established or bred.

Nankeen night herons occur along rivers and streams, roosting during daytime in dense cover of both native and introduced evergreen trees. Isolated pairs have been recorded at several places along the Whanganui River, always close to human settlement. Small concentrations are known from Jerusalem|Hiruhārama, Kauarapaoa Rd and Raorikia|Kemp’s Pole, near Kaiwhaiki, and at Ūpokongaro, in the grounds of the local café. These roosts are situated away from the Whanganui River itself, either being close to human habitation (Jerusalem|Hiruhārama, Ūpokongaro), or along a stream and in nearby forest (Kauarapaoa Rd and Raorikia|Kemp’s Pole). Numbers at the latter roost vary from 2 to 18, not following any clear pattern through the year. Numbers at Ūpokongaro are somewhat more consistent, with the monthly variations more likely reflecting seasonal changes in the birds’ behaviour (the birds being less obvious when they have fledged chicks), combined with fluctuating observer coverage.   

Population

The size of the Whanganui River population is not known. The birds’ secretive nature makes them difficult to census. Based on the numbers at the various sites where they are regularly recorded, the current population is unlikely to exceed 50 pairs. The record of a recent fledgling and a nest at Ohakune, outside the Whanganui River catchment, may suggest a slow expansion.

Threats and conservation

No conservation measures are in place. Adults may be vulnerable to disturbance when breeding, and to predators when feeding, but are generally wary. At Ūpokongaro, a juvenile female New Zealand falcon was seen resolutely pursuing an adult night heron through riverside trees. Despite clipping the night heron, which fell into the river (and then scrambled out into the vegetation), the falcon did not press its advantage. On another occasion, a roosting adult adopted a threatening posture—extended neck, ruffled neck feathers and erect head plumes—when apparently facing off a morepork perched about 30 m away. Eggs and young chicks are likely to be particularly susceptible to predation. A just-fledged chick on the ground at Ūpokongaro fended off a threatening feral cat, but such birds could be susceptible to ambush.

Breeding

For many years, the only confirmed breeding record was a nest found November 1995 at Jerusalem|Hiruhārama. That nest was located in bush on a steep slope above the Mangoihe Stream, 600 m from its confluence with the Whanganui River. It held three unequal-sized chicks. Three other apparently empty nests were seen nearby. Then, 27 years later, in 2022, a small breeding colony was discovered in the grounds of the local café at Ūpokongaro, in trees overlooking the Ūpokongaro Stream,

Nests are platforms of loose sticks, measuring 45–60 cm in diameter and 10–15 cm deep in the centre. Some at Ūpokongaro have been reused the next season, becoming bulkier with the addition of new sticks. In one instance, birds were seen removing sticks from an early abandoned nest to a new one higher up in the canopy of a holm oak.

Nesting takes place between October and April, with chicks fledging from late December to early April. The number of nests recorded at Ūpokongaro during the between 2022 and 2025 was 4, 6 and 11 nests from which 7, 10 and 16 chicks fledged, respectively, giving an overall average of 1.6 fledglings per nest. These exclude two initial nests in 2022-23, which either failed or were abandoned early, with the pairs apparently renesting soon after. Maximum number of chicks in any one nest was three, with a noticeable size difference among them.

Both members of a pair are involved in nest building, on one occasion bringing twigs and small sticks to the nest every 5–6 minutes. During early incubation, one bird would bring twigs, which the sitting bird would add to the nest. After a change-over, the pattern continued, with the previously sitting bird becoming the provider. The shells of five eggs found beneath the Ūpokongaro colony, possibly from two or more nests. Four were apparently from hatched eggs while the fifth seemed to have been depredated. Its shell was more-or-less intact except for a large hole near one end. It measured about 55 mm x 42 mm, towards the upper end of Nankeen night heron eggs measured in Australia. The eggshells had chalky textures and were coloured light cyan (hatched eggs) to a faded green-cyan (depredated egg), also like eggs in Australia.

Both parents feed the chicks, including by foraging in daytime in the stream below the colony. Neither the rate of food delivery nor the respective contributions of the pair to chick rearing have been determined. Chicks leave the nest when about four weeks old, roaming around near the nest until they fledge three weeks later.

Behaviour and ecology

Almost completely nocturnal, most birds at Kauarapaoa and Ūpokongaro leave their daytime roosts, on average, about half an hour after sunset, when it is almost dark. Birds depart earlier during summer than they do in autumn–winter (mean departure time in summer, 18 minutes after sunset, with almost a fifth of the birds leaving before sunset, compared with an average autumn–winter departure time of 30 minutes after sunset). Much less is known about when the birds return to their roost, but intermittent observations suggest at least 45 minutes before dawn. Foraging areas are along edges of rivers and streams, or adjacent swampy areas. Roosting birds are wary and secretive, but not necessarily shy, occasionally creeping out to get a better look at an observer, or sunning themselves on the edge of roost trees, both before evening departures and during daytime on cold, clear winter days. All known sites are close to human settlement, but this may simply reflect the difficulty of locating birds elsewhere. In Australia, juveniles disperse widely after fledging, and may do the same in New Zealand. This could account for the high frequency of young birds (70%) among those recorded in New Zealand outside the Whanganui River catchment. In the southern part of their range in Australia, adults are partly migratory, moving northwards in winter, as well as moving in response to major rainfall and flooding events. Some may end up in New Zealand, as they do on other western and southwest Pacific islands.

Food

Poorly known in New Zealand. Birds at Ūpokongaro seen to take small eels, fish (galixiids, Gobiomorphus spp.) and even a cicadas, while juveniles have been observed snapping at mayflies and passion vine hoppers. One adult brought a small eel back to feed its chick. Droppings of a bird at Tarara, Otago, contained the remains of freshwater crayfish. In Australia, they are known to take fish, frogs, freshwater invertebrates and hatchling sea turtles, among other things.

Weblinks

BirdLife factsheet

Wikipedia

References

Bell, B.D. 1958. Nankeen night-herons at Blenheim. Notornis 8: 52-53.

Gibson, P. 2023. Rare beauty. Nankeen night heron in New Zealand. Unique Pictorials, Whanganui.

Heather, B.D.; Robertson, H.A. 1996. The field guide to the birds of New Zealand. Viking, Auckland.

Ihimaera, W. 2009. The Trowenna Sea. Penguin, London.

Jackson, T. 1981. Immature night heron in Otago. Notornis 28: 217-218.

Lambert, R. 1981. Another nankeen night heron. Notornis 28: 254.

Marsh, N. 1995. Nankeen night Herons (Nycticorax caledonicus) on the Whanganui River. Notornis 42: 282-283.

Marsh, N.; Lövei, G.L. 1997. The first confirmed breeding by the nankeen night heron (Nycticorax caledonicus) in New Zealand. Notornis 44: 152-155.

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

Norris, J. 2023. Nankeen Night heron nesting colony at Upokongaro. Birds New Zealand 38: 9

Norris, J. 2025. Nankeen Night Heron winter wonderland. Birds New Zealand 47: 9

Watola, G.V. 2025. The European discovery of New Zealand’s birds (2nd edition). Publisher G.V. Watola.

Recommended citation

Frost, P.G.H. 2013 [updated 2026]. Nankeen night heron | Umu kōtuku. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz