Now, researchers from a five-year, multi-agency study have installed listening devices in Otago wetlands in the hopes of hearing the birds’ calls this spring.
Otago Regional Council terrestrial ecologist Dr Scott Jarvie said the researchers were attempting to establish the numbers and distribution of the Australasian bittern (matuku-hūrepo) and spotless crake (pūweto) to understand the implications of wetland management practices on the species.
It was rare for anyone to see matuku-hūrepo as their numbers had greatly declined after the destruction of 90% of their wetland habitat, Dr Jarvie said.
The large, rare bird could blend into its surrounding habitat which was typically difficult to access.
"The distribution of matuku-hūrepo and how many individuals are in Otago is currently unknown.
"Anecdotally, there is only a small number of matuku-hūrepo in the region, which is why the next phase of surveying is so important."
During the first year of the study, this past year, matuku-hūrepo were recorded in the Catlins, the Sinclair Wetlands and near Queenstown.
Birds New Zealand ornithologist Mary Thompson, of Dunedin, said the research group would continue to scout locations in the hopes of turning up more bittern habitat.
During the birds’ breeding season from August to December, adult males made a distinctive hollow-sounding call, similar to the sound made when blowing over the top of a bottle, Ms Thompson said.
Department of Conservation technical adviser Bruce McKinlay said any sightings of the bird should be reported.
Forest & Bird Tautuku restoration project manager Francesca Cunninghame said late last year the researchers uncovered the cryptic crake in the Fleming wetland, within Forest & Bird’s Lenz Reserve, near Papatowai in the Clutha district.
It was the first report of the bird in Otago since 2015 and the first verified record of the bird in this part of Otago.
The researchers had subsequently heard pūweto on several occasions in the Fleming wetland, including a winter survey where the entire wetland was checked.
A further survey was now planned for later in the year to try to get a better estimate of numbers, she said.
The research group includes members from the regional council, Birds New Zealand, Doc, the University of Otago and Forest & Bird.
- Also found in Australia and possibly New Caledonia.
- Global population may be less than 2000.
- Aotearoa New Zealand population estimated to be between 250-1000 mating individuals, and they have a predicted and ongoing 50%-70% decline .
- 90% of their original wetland habitat has been lost through drainage and land development.
- Vulnerable to introduced predators; cats, stoats and rats.
- Some also killed when hit by vehicles on roads.
- Starvation is a problem for some birds, indicating poor freshwater ecosystem health.
- They are a taoka (treasure) to Māori and appear in legends, stories, early pictures and metaphor. Numerous place names refer to them. They were once an important food source and their feathers were used for ceremonial decoration.
Pūweto / spotless crake
- Solitary and monogamous, and breeding occurs deep in wetlands.
- 90% of their original wetland habitat has been lost through drainage and land development.
- Vulnerable to introduced predators; cats, dogs, stoats and rats.
- Some are also killed by vehicles on roads or by flying into power lines.
- They may move between wetlands regionally and nationally.
- They are a potential indicator of wetland health, being dependent on the presence of high-quality and ecologically diverse habitats and rich food supplies.
