Love Bittern Project national co-ordinator Wendy Ambury shows how bitterns freeze and point skyward when threatened, rather than flying away. Photo / Susan Botting LDR
Love Bittern Project national co-ordinator Wendy Ambury shows how bitterns freeze and point skyward when threatened, rather than flying away. Photo / Susan Botting LDR
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.
Love Bittern Project national co-ordinator Wendy Ambury with the van she travels the country as part of the project's nationwide education campaign. Photo / Susan Botting LDR
The three-day Great Matuku Muster runs from today until Sunday.
But Ambury said October 19 was most 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 as they come 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 an hour and a half 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.
Love Bittern Project national co-ordinator Wendy Ambury with the app used to record birds during the survey. Photo / Susan Botting LDR
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, with hardcopy forms also available, Ambury said.
An initial Great Matuku Muster survey was done in September and another one will take place on November 15-17.
Matuku-hūrepo are found from Cape Reinga to Stewart Island.
Bitterns' presence indicates healthy wetland systems, Love Bittern Project national co-ordinator Wendy Ambury says. Photo / Susan Botting LDR
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.
The matuku-hūrepo is New Zealand’s largest heron, weighing up to 1.4kg, and it lives in freshwater and coastal estuarine wetlands.
When under threat, the bird freezes, its neck pointing skyward.
Ambury said this could make it as tall as a dining table.
Analysis of bittern feathers showed they were under nutritional pressure nationally, in comparison with analysis of feathers from bitterns from museums.
Widespread destruction of wetlands had been a major contributor to the birds’ habitat loss.
The matuku or Australasian bittern is New Zealand’s largest heron, weighing up to 1.4kg, and it lives in freshwater and coastal estuarine wetlands. Photo / Imogen Warren
Matuku-hūrepo once gathered in large flocks but were today seldom seen, and if so were usually solitary birds.
Northland Regional Council (NRC)’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 saw signs put up in areas where there was wetland habitat near roads.
A bittern warning sign on Mohakatino Rd, SH3 near Mōkau, urging drivers to slow down.
On September 10, new signs were put up on State Highway 12 after collaboration between NRC, Department of Conservation Kauri Coast and Kaipara District Council.
■ LDR is local body journalism co-funded by RNZ and NZ On Air.
