Australian wildlife ecologist and bittern expert Matt Herring visited last year and took the time to catch up with his New Zealand counterparts.
“The best thing we can do for nature is simply spend more time in it. From there, reverence grows and action flows.” M Herring, 2013
What a wonderful trip. It was as if we spent a week compiling precious pieces of a rare, incomplete jigsaw puzzle called “Australasian Bittern Ecology and Conservation”.
After several years of being in touch via email and phone, it was so nice to finally get together with the New Zealand bittern crew and see some of their sites first hand.
There is some great work happening across the ditch and a strong sense of being united in working towards reversing the decline of this iconic waterbird that we share. It is affectionately known as matuku hūrepo in Māori, or matuku for short.
The knowledge exchange began with the biennial National Wetland Restoration Symposium in Napier where I was honoured to be a keynote speaker, focusing on the importance of community engagement, novel habitats and active management.
We then had a day visiting wetlands around Hawke’s Bay, including Pekapeka Swamp, followed by a successful bittern workshop day organised by Matt Brady from DOC. It was now crystal clear to me that there’s a lot of love for matuku in New Zealand.
With much discussion about wetland restoration targeting bitterns, it was astounding for many folk to learn about bitterns in rice and how bare, ploughed paddocks ready for sowing are able to support nesting bitterns less than three months later. There was a range of inspiring case studies from around New Zealand at the workshop, and we got to visit some local work in Hawke’s Bay with Hans Rook.
After that, it was time to begin a broader tour of bittern sites across the North Island. First stop was Lake Whatuma, and thanks to John Cheyne and Bernie Kelly, we were able to track some bitterns while kayaking.
We discussed key issues like willow control, raupo (cumbungi) harriers as bittern nest predators.
This wetland has up to nine booming males, but far fewer females, perhaps only three. The apparent shortage of female bitterns across New Zealand is something DOC’s Emma Williams is very concerned about. We may well have the same problem in Australia.
males in rice fields have up to three nesting females in a single territory, there is emerging evidence that would support a general shortage of females here too. It’s definitely something we should consider: a booming male may not be a sufficient indicator of breeding
or site quality.
It was now October and time to visit the 7200-hectare Whangamarino Wetland, between Auckland and Hamilton. This Ramsar site was once the world’s most important wetland for the Australasian bittern, with more than 140 booming males in 1980.
Nowadays, there’s only about a dozen. I learnt about the many issues that are implicated in the decline, such as introduced species and water quality, but I think the huge water level fluctuations are central.
Near Tauranga, we visited the Lower Kaituna Wetland, and were lucky enough to spot a bittern feeding in the eleocharis. Part of the restoration work in the broader area is starting from scratch, essentially constructing new wetlands.
And on the edge of Tauranga itself, right on the coast, we visited a bittern breeding site that was tidal. This was quite perplexing. The vegetation is low and we wondered where they build their nests without being flooded.
Unfledged chicks have been found in land nearby, including a recreational park. We talked about how this site would be suitable for a thermal drone in locating nests and monitoring breeding success.
All in all, a wonderful trip, with special thanks to all who made it possible. I’m looking forward to returning the favour!
The love for matuku in New Zealand is admirable, and the conservation work being done is inspiring
Two DU directors, John Dermer and Dan Steele made the news this year,
both appearing in mainly rural papers, and both for very good reasons.
New Zealand is full of great places and hidden treasures. DOC knows because they manage over 1400 great places, each with its own special appeal.
This Conservation Week DOC is making it fun and easy to get out and explore the great outdoors. They are hosting activities and events around the country. Even if you can’t make it to an event you can encourage some mates to join you in an adventure, tell your friends about somewhere you love to go, or get your kids to be creative.
There is a range of things to do and see so head out with family and friends and explore the great outdoors – it’s fun and easy! Go to www.doc.govt.nz for more information.
Bitterns are found throughout New Zealand - in the North Island they predominantly inhabit Northland, Waikato and East Coast wetlands; while in the South Island they mostly inhabit West Coast, Canterbury and Southland wetlands. The most important bittern site nationally is Whangamarino Wetland, a large and diverse wetland complex in the Waikato.
Bitterns are large, stocky birds, with streaky dark brown and beige plumage on their throat, breast, abdomen and thighs; and dark brown on the neck and back. The head is dark except for pale beige around the cheek, forming a pale eyebrow. Plumage can vary significantly and may be age related.
Bitterns are rarely sighted due to their exceptionally cryptic behaviour, inconspicuous plumage resulting in excellent camouflage and the inaccessibility of many wetlands. They are mostly active at dawn, dusk and throughout the night. Bitterns are occasionally spotted in the open along wetland edges, drains, flooded farmland and roadsides.
They are very sensitive to disturbance and will silently creep away to avoid detection, or adopt the infamous ‘freeze’ stance (with the bill pointing skyward) if approached. This allows bitterns to blend into many environments, whilst maintaining a close watch of surroundings. If an observer continues to advance on a bittern, then it will eventually take flight in a laborious manner.
Often the only sign of bittern presence in a wetland is the male’s distinctive booming call at the beginning of the breeding season. Each call sequence may consist of 1-10 individual booms, with an average of 3 booms. Boom sequences are repeated at regular intervals, and normally preceded with inhalations or gasps. Females are mostly silent, apart from producing an occasional ‘bubbling’ sound upon return to the nest, or a nasal ‘kau’ when alarmed. Bitterns in flight may produce a resonant ‘kau’ or ‘kau kau’.
The breeding season is extremely long, spread over a 10-month period. Females construct a reed platform nest amongst dense vegetation deep within wetlands.
A clutch of 3-6 eggs is produced between August and December (peaking in November), and then incubated solely by the female for 25 days. Chicks remain in the nest for 7 weeks and fledge from November to May. Bitterns are considered an indicator of wetland health, as they are dependent on the presence of high quality and ecologically diverse habitats, which are rich in food supplies (such as eels, fish, freshwater crayfish, aquatic insects, molluscs, worms, spiders, frogs and lizards).
Bittern numbers have declined drastically since the arrival of European settlers, with over 90 percent of freshwater wetlands now drained and cleared. Ongoing wetland degradation continues to be the chief threat, resulting in habitat modification and loss, reduced food availability and poor water quality. Other threats contributing to bittern declines include predation by introduced mammals (particularly cats, rats, dogs and mustelids), human disturbance of nesting bitterns, as well as power-line and vehicle collisions.
You can help bitterns by becoming involved in wetland conservation and reporting all sightings (or calls) to your local Department of Conservation office. Most importantly you can protect wetlands on your property by planting native vegitation to create riparian buffers and fencing waterways from livestock.
Wildlife Project Administrator
(supplied by The Isaac Conservation and Wildlife Trust)
Project Taranaki Mounga, a ten year $24 million project involving pest eradication and reintroduction of species over the 34,000ha of Egmont National Park was last December given the green light with a funding commitment by the NEXT Foundation.
Local philanthropic organisation the NEXT Foundation announced it would invest up to $15 million in the restoration of Taranaki’s native ecology. The Foundation has committed to funding Project Taranaki Mounga, a 10 year project involving pest eradication and reintroduction of species in Egmont National Park.
The venture between the NEXT, DOC, iwi, and the Taranaki community will begin with pest and weed control and the ecological restoration of Egmont National Park and a small number of volcanic peaks and offshore islands. NEXT and DOC have committed to funding the first phase of 18 months with strong interest from other parties. DOC has committed just over $1.6 million for the first phase.
Work will start on phase one this February and during the 18 months the project intends to:
DOC Director General Lou Sanson said he was thrilled Project Taranaki Mounga has been given a green light with the commitment of funding from the NEXT Foundation.
“Project Taranaki Mounga has been recognised as one of the next big exciting and bold conservation ventures,” said Lou Sanson.
The project’s vision is to protect our mountain for our wellbeing – Ko Taranaki tooku whakaruruhau.
“Given the strong Iwi connection and Whakapapa to Taranaki Mounga, Iwi are a critical partner in the successful delivery of this project.
Lou said the project will create a legacy of cultural, environmental and economic benefits for generations to come.
“Healthy flourishing ecosystems will sustain the quality and abundance of freshwater underpinning the Taranaki economy which adds to New Zealand’s image, and showcases this country’s leadership in pest eradication.
“It’s exciting knowing lessons learnt in Taranaki will be able to be transferred to even larger landscapes when successful,” said Lou.
The Isaac Conservation and Wildlife Trust’s seven brown teal/pateke breeding pairs laid their first clutches, with 34 ducklings hatched in total.
Laying of second clutches has now begun. Two older pairs have been released on Rotoroa Island in the Hauraki Gulf, making way for a clutch of orphans coming off Great Barrier Island – providing new genes for the captive breeding programme. The Trust continues to be the major breeder in producing the largest brown teal output for release into the wild.
Find out more about the Trust’s captive breeding activities on Facebook