Northlanders are among 600-plus New Zealanders signed up to be part of the country’s first nationwide citizen-science Australasian bittern count.
The Great Matuku Muster will help build the first national database for how many Matuku-hūrepo (Australasian bittern) there are and where the birds live.
At present there are thought to be as few as 250 birds, with potentially 1000 across the country.
Ngunguru-based Love Bittern Project national co-ordinator Wendy Ambury said the elusive large wetland bird was one step away from extinction.
Building more reliable data helped in the fight against its disappearance.
The three-day Great Matuku Muster ran from Friday until Sunday.
But Ambury said October 19 was most the important monitoring night of the year among three monitoring sessions in September, October and November. The breeding season’s start coincides with the return of whitebait and eels from the ocean coming back to breed.
Those who take part in the survey will be listening for the male bittern’s distinctive booming as it courts and protects its territory.
This will be done from around 1.5 hours before sunset till half an hour afterwards, or in the morning an hour before sunrise.
The booming survey days are centred on the month’s full moon and two shoulder days, because that is when the birds are most active.
People could survey for a single night or the full three. They would register to take part, be sent supporting material and guided to an appropriate monitoring spot, if they didn’t have one in mind.
They needed to be near wetlands, either freshwater or coastal estuarine and listen there.
Their monitoring information would be loaded on a provided app, or hardcopy forms were also available Ambury said.
An initial Great Matuku Muster survey was done in September, and another one will be on November 15-17.
Matuku-hūrepo are found from Cape Reinga and Stewart Island.
Ambury said upper North Island matuku-hūrepo started booming in September as they jostled for mates and territory, with their booming peaking in October as they settled.
From the lower North Island south, the birds started jostling for partners and territory in October, peaking in November.
Great Matuku Muster data is loaded onto the Love Bittern Project website.
The matuku-hūrepo is New Zealand’s largest heron, weighing up to 1.4kg, and it lives in freshwater and coastal estuarine wetlands.
The bird freezes, its neck pointing skyward, when under threat.
Ambury said this could make it as tall as a dining room table.
Analysis of bittern feathers showed they were under nutritional pressure nationally, in comparison with analysis of feathers from bitterns from museums.
Widespread wetlands destruction had been a major contributor the birds’ habitat loss.
Matuku-hūrepo once gathered in large flocks but were today seldom seen, and if so were usually solitary birds.
Northland Regional Council’s website says the matuku-hūrepo was one of a small number of native wetland predators that ensure healthy wetland biodiversity.
The site has a Northland bittern locations map, showing the bird’s distribution in the region, where new local Great Matuku Muster information would also be added.
Bittern populations have been decimated by wetland drainage and habitat clearance, which also results in less food availability and birds starving over winter.
New “Slow for Bittern” road signage was recently installed on Pouto Rd near Dargaville to warn motorists.
It followed the death of a matuku-hūrepo there in August.
A cross-agency effort to reduce this risk resulled in signs being put up in areas where there was wetland habitat near roads.
On September 10, new signs went up on State Highway 12 following collaboration between the Northland Regional Council, Department of Conservation Kauri Coast and Kaipara District Council.
LDR is local body journalism co-funded by RNZ and NZ On Air
