Australasian bittern survey asks volunteers to listen for booming calls

She said people were being asked to give as many evenings as they could during the 10 days between Friday and Sunday, November 1 to listen for male bittern booming at local wetlands around sunset, then record online or manually what they heard.

The first of New Zealand’s three 10-day listening times in 2026 was in September, when about 87 community groups and individuals recorded bittern booming around the full moon from north of Kaitāia to Hokitika on the South Island’s west coast.

The October survey is the second. The third count will be from November 20 to 29.

Ambury said bitterns were “on fire” with their booming.

October is the peak annual booming time, when male bitterns seek mates by making the sound.

A female bittern called in would look carefully to see if the wetland he was in was to her liking before pairing up, Ambury said.

Booming typically started in Northland and shifted later through the three-month listening period, she said.

The number of people taking part in the nationwide project this year was expected to double on 2025, she said.

Bitterns laid about three eggs in a clutch that took about 24 days to incubate, she said.

Bittern chicks would start hatching from October in the north, where the season tended to be earliest.

Volunteers are being asked to visit a local wetland around sunset and spend 60 to 90 minutes listening for the distinctive booming call.

The secretive wetland bird is difficult to monitor because it spends much of its time hidden among reeds and rushes.

Conservationists rely on its far-carrying boom to estimate numbers and identify where the species is found.

People can take part individually or as part of a community group by registering online and downloading the Conservation Hub app to record observations.

Participants are encouraged to survey the same wetland for one to three consecutive days, noting any booming calls and entering the information into the app or recording details manually.

The information collected contributes to a nationwide picture of the bird’s distribution and abundance, helping guide conservation efforts for a species that has suffered significant declines as wetlands disappeared.

An Australasian bittern on the Pātaua South roadside that wowed an NRC councillor on her morning commute from the tiny seaside settlement.

Northland Regional Council (NRC) said: vehicles are among the greatest risks facing Northland’s Australasian bitterns with roadside signs aiming to make drivers aware and take care.

Northland now has several roadside Australasian bittern warning signs:

Far North – Kohukohu in north Hokianga.Tokerau Beach’s Inland Road.Kawakawa oxidation ponds.Kaipara – Lake Rototuna.Pouto Point; SH14 Rotu/Maitahi.Taingaehe/Pouto; Mangawhai’s King Road.Whangārei district – Ruakākā’s Doctors Hill Road.Parua Bay’s Lamb Road; Pātaua South.Ngunguru Road and Punaruku.

NRC councillor and freshwater ecologist Amy Macdonald called on Te Tai Tokerau/Northland residents and visitors to take part.

NRC councillor Amy Macdonald says bitterns are a great way to get people including farmers more interested in protecting wetlands on their property.

Macdonald has been delighted to see two bitterns this week in swamps near her Pātaua South home.

Macdonald recently urged people to get behind the Australasian bittern in New Zealand’s Bird of the Year competition.

■ LDR is local body journalism co-funded by RNZ and NZ On Air.