Makarora Whio (Blue duck, Hymenolaimus malacorhynchos) ~ A significant remnant population of Aotearoa New Zealand’s, South Island

The dedicated work of Aspiring Biodiversity Trust (Est: 2017) has enabled a better understanding of the current population status of Whio (Blue duck, Hymenolaimus malacorhynchos) within the Makarora/Makarore and Wilkin/Ōtānenui catchment, South Island of Aotearoa New Zealand. Furthermore, this work has highlighted the importance of the Makarora population in terms of maintaining the genetic diversity of this ancient waterfowl species (the sole member of its genus). This is “no ordinary duck!”

Makarora Whio (Blue duck) South Island

New Zealand Endemic with strong spiritual, cultural, historic Māori value. Freshwater environmental indicator species.

IUCN Threat Category: Endangered

NZ Threat Classification: Vulnerable

It is well known from previous studies that the North and South Island whio represent two genetically distinct lineages (managed as separate units). In the South Island there are known differences in the North and the South with central mixed assemblages. However, it is not known where the Makarora Whio fits in terms of its genetic origin in relation with other South Island populations. This work unravels the mystery of the Makarora Whio. Furthermore, it provides important insight into whio dispersal and finally puts the Makarora Whio on the map. Details found here in the latest published edition of the Notornis Journal.

Whio Recovery Site Locations (2009-2019) with Makarora added.

Since this work, further whio genetic samples have been analysed and the Aspiring Biodiversity Trust are starting to see positive results for whio from their dedicated invasive predator control programme – from ridge to river. Positive evidence includes up to x 5 ducklings and sightings of x 8 birds at a single breeding location. Cumulatively ABT’s work is having additional biodiversity gains by protecting other indigenous species such as the alpine Pīwauwau/ Rock wren and Kea (IUCN endangered) within Mt Aspiring National Park. With the likely impacts of climate change, it is essential that we know about current endemic remnant species populations to prevent local extinction where possible whilst optimising resources.


Glaser et al (2019). Whio/ Blue duck Recovery Plan 2009 – 2019. Threatened Species Recovery Plan 62. Wellington, NZ, Department of Conservation.

Grosser et al (2017). Strong isolation by distance argues for separate population management of endangered blue duck (Hymenolaimus malacorhynchos). Conservation Genetics 18: 327–341.

Hufton & Robertson (2023). A significant remnant population of whio (blue duck,
Hymenolaimus malacorhynchos) bridging the gap between Fiordland and West Coast Recovery Sites, South Island, New Zealand
. Notornis, 2023, Vol. 70: 190-195.

Makarora whio pair with 5 ducklings (Oct 2023), observed during ABT’s routine riparian invasive predator control maintenance by S Gillam, ABT Field Team.

Kakī/Black Stilt (Himantopus novaezelandiae) recorded at Makarora

A monumental moment, when a pair of the world’s rarest wader’s turns up unexpectidly at Makarora (North Otago) at the start of the bird breeding season and then… realisation that you were at the captive release of one of them five years ago. The Kakī/black stilt (Himantopus novaezelandiae) is a critically endangered endemic wading bird considered important taonga (a living treasure) by Māori. The kaki is thought to be monogamous and birds often pair for life.

Kaki/ black stilt pair foraging over emphemeral grassland pools Makarora – August 2021

Leg colour band records have shown that both birds were hatched in the Department of Conservation captive breeding facility at Twizel and later released on the Tasman. Since then, they were first seen together on 9 Sept 2019 on the Tasman, in 2020 and also on 25 Feb 2021. Neither one has bred yet and now they are present at Makarora!

BkRBk/GW hatched on 26 Nov 2015 (5y old), released on the Tasman as a sub-adult (below bottom right at original release site) Aug 2016.

Kaki sub-adult BkRBk/GW (bottom right) at the Tasman release site – Aug 2016

GBkO/BkW hatched on 14 Nov 2017 (3y old), released on the Tasman as a juvenile in Jan 2018.

The presence of this species along with reguarly recorded wrybill, black-billed gull, banded dotterel, South Island pied-oystercatcher, pied stilt and black-fronted tern now completes the migratory braided river avifauna composition for Makarora.

Kakī have been intensley managed since 1981 when the population declined to a low of just 23 birds. The Department of Conservations Captive Breeding Centre in Twizel plays an essential role in the Kaki recovery programme. Conservation efforts to date have succeeded in averting extinction and increasing Kaki numbers. The current population of adult birds is now around 170 (per coms Aug 2021 DOC Twizel).

The main threats to kakī include: introduced invasive mammalian predators, habitat loss and human disturbance. Kakī are found within braided river habitat, associated pools and wetlands.

Kaki/ black stilt foraging at Makarora

Historically they were present throughout the braided rivers of the South Island, however today their spatial distribution is concentrated around the current release sites of the Tasman and the Godley Rivers with records of dispersal on the east coast near Christchurch, the top of the South Island and the south coast near Riverton. Within the Southern Lakes region the only other record (2020) is of a single kakī from the delta of the Matukituki River at the base of Lake Wanaka but this is the first time kakī have been recorded at the north of Lake Wanaka in Makarora since 1983 (when a pair was last confirmed nesting).  Could this be a promising sign that this important taonga is ready to thrive beyound its original release sites..?

South Island kaki distribution (purple NZ Ebird) in relation to recent record, origial release site and the Captive Breeding Facility.

The kakī pair have been included within ABT’s braided river bird monitoring observations and reporting and certainly adds further validity to current ABT and other invasive predator control operations within the catchment. We hope they stay for the season and maybe even attempt to breed here!

Adult kaki (Makarora) showing colour leg bands on left leg used to identify individual birds (BkRBk/GW). Note colour bands fade over time.

Kaki primarily like to feed on insect larvae often in the subtrate of wetland habitats, molluscs, crustaceans and worms. They often feed by scything for worms and midge larvae in soft substrates and can be found sharing with the more common poaka/ pied stilt.

Thanks to Twizel DOC staff; Cody Thyne and Claudia Mischler following our colour band reporting for historical data on this excitng rare bird record.

“This sighting is super exciting for us. I can’t thank you enough for letting us know. I’d be interested to see what they end up doing – will they stay, will they move and be found elsewhere, will they breed? So if you happen to keep seeing them, please do let me know!”

Author and kaki observer: Rachel Hufton, image Rachel with Cody Thyne (Doc Twizel) at the original Kaki release site of BkRBk/GW, Tasman delta August 2016.



NZ Archives – Reserves – Wildlife – Wildlife Management – Makarora

A young kaki at the Twizel avariy before release Aug 2016

The First Makarora Field Course – A Success!

The first  Makarora Field Course was held from the 10 – 16 January 2021. This was the successful result of a partnership between Aspiring Biodiversity Trust and Operation Wallacea (Opwall) with support from LINZ, Birds New Zealand, Makarora Wonderland, local landowners and Wilkin River Jets.

The purpose of the field course was to promote the indigenous biodiversity of the Makarora catchment, create a valuable learning opportunity for students interested in careers based around wildlife management and conservation, contribute to good biological recording, whilst encouraging the future caretakers kaitiakitanga of the natural environment.

Students arrive at Makarora Field Course – yey!

Makarora Field Course Base Camp

Students from Wellington, Auckland and the Coromandel were met at Queenstown Airport, then joined a scenic coach trip over the Crown Range via Wanaka and Lake Hawea to the field course base camp at Makarora. Here the students and teachers were met by the ABT Science team and a representative from Operation Wallacea. The event commenced with a welcomming karikia before entering the learning facility for a welcome presentation and briefing. Students were then  shown to their tents before the first group meal was served at the main Makarora Wonderland Lodge.

Forest vegetation plots

Bird banding and mist netting with NZNBBS certified bird bander

The week was divided into a series of applied learning activities focused on biological (fauna and flora) recording survey methods and monitoring with classroom sessions on data analysis, reporting and the use of the R Stats application via an overseas connection with Opwall lecturer’s in the United Kingdom.

Evenings were filled with lectures on geophysiography, protected species detection dog aided surveys (for whio), ABT’s Ridge to River Threatened Species Programme, a forest by night walk and concluded with a session on career’s in conservation and wildlife management with an inspiring and motivational finish for the future from Aspiring Biodiversity Trust patron – Lydia Bradey, recently awarded a New Zealand Order of Merit.

Braided river session including fluvioglacial processes, aquatic inverts and avifauna.

An awesome week of incredible weather and biodiversity concluded with a splendid Wonderland BBQ and a certificate presentation to students on their completion of the field course, plus the awarding of prises (including a NZ bird guide) for various notable achievements over the duration of the weeks activities. A farwell karikia and celebratory cakes completed a most memorable week for all involved.

Protected species survey dog, Hoki.

Thank you  to all funders and supporters who helped enable the first pilot Makarora Field Course. The next Makarora field course dates start from 7-14 January 2022! Get in touch to find out more about the latest itinerary, we look forward to hearing from you 🙂

Lydia Bradey motivational talk following career’s panel.

Commentary from student, staff and parent post 2021 field course:

I would like to thank the team for providing an amazing experience for my son Aditya. He is very grateful to get this wonderful opportunity of working with the best in their fields at such a young age. The communication, management and service has been great fro this trip. Thanks again. Jyoti

Thanks for running such an awesome course here in such a beautiful place. You and your team have provided invaluable insight into the real world – science and ecology. Hope to be back in the future. Dylon

By seeing the banded dotterel chick and other amazing sights, I felt like I was learning in a real meaningful way. Thanks, Fiver

Rachel, we did it! Congratulations on puttng together such an amazing field course you should be very proud of what you have achieved. It has been a real pleasure working with you! Hopefully we can do it again. Jihan



Braided river bird surveys and the challanges of nature

The fourth annual braided river bird walkover survey was a touch more challanging this year due to unsettled weather conditions with strong winds, sandstorms, downpoors and subsequent rising river and lake levels. This highlights the necessary considerations involved such as timing and weather monitoring before undertaking this important work.

A gusty second day on the river with water levels rising after a night of rain. Image Karthic

The Aspiring Biodiversity Trust team were determined to complete the length of the river walkover from Boiler Flat down to the river delta and with the additional help of a new volunteer Karthic (to the left below), a wildlife and conservation film maker with Natural History New Zealand (NHNZ) from Dunedin. Karthic found the experience “quite an eye opener” and savoured the remoteness of the location throughout his stay. He hopes to return when conditions are more suitable for wildlife filming!

Walkover sections being divided up to help maximise cover of braided river bird habitat by surveyors

The ABT bird surveyors in action (above) planning survey route sections and safe river crossings. All key braided river bird bird species were present however in generally lower numbers with more dispersed distribution in comparison to previous years. Total counts will be analysed and compared with national trends for key braided river bird species. This was the first wrybill pair of the year recorded foraging along the waters edge.

Female wrybill with a more slendar neck collar

Male wrybill with a wider neck collar and black patch to the forehead

The male and the female are very similar, with subtle differences in colouration and markings. Nick Beckwith a regular ABT volunteer captured this pair nicely on the first survey day.

A nest site was later found (below) the pale grey eggs and nest site highlight the incredible cryptic adaptations of these species enabling them to breed in such a harsh environment with considerable threats.

The female had briefly left this nest site (below) to forage on aquatic invertebrates along the nearby waters edge which enabled this image.

A wrybill nest site on the Makarora River

Thanks to Wilkin River Jets who facilitated the lower Makarora River section of the survey and the upper Wilkin River section. Image below shows the view up the Wilkin Valley from the jet boat, with snow capped Mt Aeolus in the background. There was certainly a crisp chill in the wind that day despite the blue, blue sky.

The team were fortunate to be able to stay at Makarora during the surveys especially during the busy production of a new top secret film (due out in March 2021).

As the day came to an end for the wonder that is Makarora, the stars appeared and the familar call of a pair of morepork/ ruru could be heard from the forest alongside the soothing flow of the river. Morepork presence is a positive indication of ecosystem health and this species appearers to be increasing in the valley.

The night sky – looking west over the Makarora River towards the Young Valley. Image Nick Beckwith.

*Thanks to all involved and those who helped enable this work. Including Sarah Forder, Nick Beckwith, Karthic SS, Danyel and Alex at Wilkin River Jets, Mt Albert Station and Dan and Carol Orbell.

Funding support provided by (LINZ) Land Information New Zealand.


Spring in the Makarora Catchment – From Ridge to River

Coffee break at Jumboland airstrip (the Coru Lounge)

With this seasons work programme in full swing, spring 2019 marks the installation of ABT’s upper river predator control for whio or blue duck (Hymenolaimus malacorhynchos) protection within the Siberia Valley and the Wilkin Valley. This follows previous walkover survey work with the aid of a protected species dog specifically trained in the detection of whio; New Zealand’s ancient waterfowl species, an important part of Makarora’s indigenous taonga.

A whio pair (also known as blue duck) recorded within the Wilkin Valley Feb 2019

Here remnant populations of whio still remain however numbers are low and fledgling survival is limited by the presence of invasive predators such as stoat and rat. This can often lead to a sex ratio imbalance as females tend to be more vulnerable when nesting and during moult. The new trapping networks join up with alpine trap lines to help extend invasive predator coverage for this globally endangered species.

Predator control traps delivered by Backcountry Helicopters into mid-Siberia Valley. Photo credit Pilot Blair

Spring is also the time to resume alpine predator control operations for rock wren and kea protection. New traps added and a number of stoats, and rodents had been caught over the winter months despite not all traps being accessible at higher levels due to the amount of snow still present (these traps will be serviced next visit).

Invasive mammal trap exposed from the snow at Upper Lucidus (September 2019).

A mummified stoat caught at altitude during the winter months

Rock wren pairs were active at the Crucible Basin but all was quite in the upper Wilkin Valley (where snow cover heavier) suggesting that this population may not of yet stired from their winter torpor. Kea were heard calling above the Siberia Valley  and one in the upper Wilkin.

Crucible Basin trap drop off with Backcountry Helicopters and logistical planning for the day ahead

Snow cover along the ridge of Lake Crucible looking towards Gillespie Saddle (Oct 2019). The characteristic call of the rock wren is often heard here.

Back in the lower river valleys of the Makarora and Wilkin, braided river birds have returned and are starting to nest again. ABT braided river invasive mammal predator control continues on a monthly basis throughout the year with the help of regular volunteers. Stoats, rats, hedgehogs and feral cats are being reduced to help improve fledgling success of endangered birds such as black-fronted tern, wrybill and black-billed gull. The Southern black-backed gull is a avian predator of endangered braided river birds and their chicks. Adaptive management of this species is due to progress this season also.

Makarora braided river habitat showing the Wilkin confluence and the head of Lake Wanaka


With thanks to all our volunteers, funders, partners and supporters 🙂

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