It’s not over, plover — yet
The Shore Plover Recovery Programme aims to turn the tide on the fate of one of the world’s rarest shorebirds
The shore plover is described as a bird in need of urgent PR. With just 250 individuals left in the wild on several predator-free islands, it is one of the world’s rarest shorebirds, facing issues related to real estate, genetics and a pandemic.
Through collaboration and cooperation with tangata whenua, tchakat henu (Moriori), community groups, and other stakeholders, the Doc-led Shore Plover Recovery Programme aims to turn the tide on this bird’s fate.
The bimonthly, Tu¯turuata Telegraph takes a closer look at what it takes to bring this unique species back from the brink of extinction.
In 1873, in reference to reports that shore plover were rare, keen ornithologist Thomas Potts commented, “It is not unlikely that the idea of its reputed rarity has arisen rather from the lack of close observation than from the scarcity of the species.”
Ironically, his accompanying observation of three pairs of shore plover at the mouth of the Waikawa River in Otago was the last on the New Zealand mainland.
For the next 120 years, shore plover, or tu¯turuatu, were only known to exist on South East (Rangatira) Island in Re¯kohu / Chatham Islands, named for its orientation to the Chathams’ second largest motu, Pitt Island.
It’s Moriori name, Hokorereoro, is more revealing of its nature, loosely meaning “the vibration of flight” in reference to the sight, sound and feeling of the millions of petrels and shearwaters that call the island home.
Rangatira Island is home to an incredible diversity of species, reflective of the high level of endemism found in the Chathams (47 plants and fungi, 10 seaweeds, 16 birds, one lizard and more than 50 invertebrates).
It is 219ha in area, rising to 224m above its western cliffs, flanked with rocky platforms and covered with thick scrubby forest.
Rangatira is home to the majority of the black robin and Chatham snipe populations and provides for so many burrowing seabirds that DOC staff need to clomp around in a special sort-of snow-shoe to avoid destroying their homes.
At night the forest floor is alive with seabirds and invertebrates including we¯ta¯ and the large Rangatira spider. Rangatira spiders (Dolomedes schauinslandi) are one of New Zealand’s largest spiders (up to 12 cm across) and are only found on Rangatira Island.
The reason for this incredible biodiversity is that despite being a whaling shore station in the 1800s and farmed for many decades, the
island has remained miraculously free of all mammalian pests.
It is no surprise then, that here on the edge of the world, the shore plover, known as “tchu¯riwat” to Moriori, was able to cling to survival. Today, more than half the total population of 250 birds are found here.
Noted ornithologist Sir Charles Fleming visited Rangatira Island in 1937 and made important observations of shore plover breeding behaviour, ecology and population size.
Impressed by the island’s abundant wildlife and lack of vermin,
Fleming hoped the island could one day become a sanctuary and preserve the characteristic flora and fauna.
This hope was realised in 1953 when the Crown purchased the island and removed the last sheep in 1961, establishing and managing it as a nature reserve.
Despite the act there was virtually no forest remaining after its time as a farm, the island bounced back remarkably quickly and flourishes today with Chatham Islands ribbonwood, mahoe, akeake, harakeke, pohuehue, matipo and megaherbs.
There is restricted access to the island in order to protect the last refuge of the shore plover, the biggest population of critically endangered black robin, the Chatham petrel and
several other species.
Thinornis Bay, found on the northeast corner of Rangatira Island, is named for the shore plover (Thinornis novaeseelandiae) that live and breed on its rocky platforms.
Recognising that a single population of shore plover on a small island was vulnerable to extinction, in the 1970s the then New Zealand Wildlife Service attempted the first translocation of the species to nearby Mangere (Moriori: Maung’ Re¯) Island. Though unsuccessful, it spurred
efforts to establish a captive-breeding population and develop release techniques.
A captive breeding population of
shore plover is held across three facilities on the New Zealand mainland, providing juveniles for release on to pest-free islands.
All the captive pairs derive from eggs collected from Rangatira Island that are transported by boat, plane and road to captive facilities. Although the captive population was founded in the 1990s, occasional transfers of eggs from Rangatira Island are required to maintain the genetic diversity of the captive and translocated populations; the most recent being in 2020.
Shore plover numbers on Rangatira Island are surveyed twice a year and chicks are fitted with metal bands to identify them.
Adult birds are sometimes fitted with brightly coloured plastic bands to allow them to be identified at a distance.
These birds act as sentinels and are checked on every visit to the island — their absence could mean the arrival of an unwelcome predator.
Before a visit, each piece of clothing
is washed in Sterigene, a biocide which kills all bacteria, viruses and spores. Boots are scrubbed of mud. Tweezers are used to painstakingly combs seams, linings and pockets for any stray invaders.
This is done to avoid any disease or pest species arriving on the island, which could be disastrous for these populations.
Visits are two- to four-week stints and everything needed is brought in by boat. Patchy wi-fi is gained standing on top of an exposed rock.
Despite its complexities, DOC staff and volunteers rave about their time on the island.
Without Rangatira Island and its remarkable pest-free history, shore plover would be just another of our many extinct species.
Our ability to introduce captivebred birds to pest-free islands, sourced from this wild population, is crucial to our aims to restore shore plover to parts of its former range and reduce the long-term risks of extinction.