|
Getting your Trinity Audio player ready...
|

It’s almost spring, the whitebait are getting set to run, and bittern are making their way to the coast to fuel up for breeding season.
Meanwhile, hundreds of volunteers right across New Zealand are getting ready to put their boots on and head out to a wetland near them to help record the ‘boom’ of the male bittern in ‘The Great Matuku-hūrepo Muster 2025’
The population of bittern is reported to be less than 1000 and declining. Bitterns are amongst our most severely threatened bird species, facing an immediate high risk of extinction.
With swift action on the ground now, the Love Bittern Project says we have the opportunity to save Bittern in their natural wetland habitats. The Great Matuku-hūrepo Muster is part of a programme to do exactly this.
The Great Matuku Muster, the first nationwide synchronised count of bittern or Matuku-hūrepo (Australasian bittern, Botaurus poiciloptilus), took place in spring last year. The 2024 muster saw 500 people stationed around the edges of wetlands across New Zealand, listening and recording the ‘boom’ sound that male bitterns make.
Coordinated nationwide by the Love Bittern Project, the muster’s results are being used to create positive action on the ground to protect Bittern and restore their wetland homes.
Bitterns are a native wetland bird classified as “threatened -nationally critical”. They are recognised scientifically as an apex predator of wetland ecosystems and as such are the ideal indicator species to measure the overall health and biodiversity of our fresh and brackish water wetlands.
Bitterns are one of New Zealand’s largest birds, yet many people have never heard of them. This is because bitterns are incredibly shy, elusive and camouflage well in their wetland habitat.
By contrast, however, their presence is easily detected during breeding season by a “boom” sound the male bittern produces. The males use their oesophagus like a set of bagpipes to release a series of deep and bassy ‘whoooom’ sounds that can be heard over a kilometre away.
Wendy Ambury, of the Love Bittern Project, says it is this unique booming character that allows those who participate in ‘The Great Matuku-hūrepo Muster’ to effectively record male bittern across wetlands throughout New Zealand.
“Collectively, we recorded only 223 individual male bittern booming in ‘The Great Matuku Muster’ in 2024; however, the value of the muster goes way beyond monitoring to get numbers. The nationwide event helps to raise awareness for bittern and connects people to their wetlands – a vital first step to help their recovery”
The muster results, combined with results from surveys using acoustic recorders, provide a better idea of the baseline population in each project area and together provide a nationwide picture which helps inform management and protection of the species.
Technology is being rapidly developed to create user-friendly apps that help participants in the field to record bittern, dramatically improving time efficiency and data accuracy. And while AI is also being used more and more to speed up the analysis of acoustic recordings, traditional pen and paper methods are still widely used to record during the muster.
Bitterns are highly mobile, capable of flying from region to region in search of wetlands that provide food, mates and security.
At this scale, Ambury says we can’t expect conservation agencies alone to record or protect the bittern; it will take community involvement to fill the gap and have enduring results.
Recognising this, the Love Bittern Project is building nationwide capacity and capability in communities across Aotearoa. The project is helping people to identify and protect Bittern, recognise the value of wetlands and encourage them to take meaningful action.
By helping bittern, we are also helping all other threatened wetland-dependent species, restoring wetlands so they are able to perform their crucial functions like water filtration and flood protection, which supports people and communities too.
Much like bittern, the Love Bittern Project crew are travelling and stopping in every region of New Zealand over the next four months, helping to deliver information and training in workshops, community hui, school visits, and ultimately supporting people in every corner of New Zealand to take their next step to help save Bittern from extinction.
To join ‘The Great Matuku-hūrepo Muster’ this spring or for more information, visit www.lovebittern.com or contact Wendy at lovebittern@gmail.com.



