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!”

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.

Reference

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.