A Little Bird for a Big Project

New Zealand’s smallest bird now has a home on Tiritiri Matangi island, after an operation that took 12 days to complete. A total of 31 riflemen were successfully caught on Hauturu / Little Barrier Island last week by a team of enthusiastic volunteers, with the birds being flown in batches across the Hauraki Gulf by helicopter.

This project has been a long time in the planning and is a joint initiative between the Supporters of Tiritiri Matangi (SoTM) and the University of Auckland, with much assistance and encouragement from the Department of Conservation.

SoTM spokesperson, Simon Fordham, is ecstatic at the result. “This has exceeded our expectations, especially as it took five days to catch our first bird. A lot of effort, by many people, will now give visitors to Tiritiri Matangi Island the opportunity to see New Zealand’s smallest bird in the Auckland region.”

This is the twelfth species of native bird to be introduced to Tiritiri Matangi Island and is another step in the restoration of the island’s ecology.

Because of their small size, survival of riflemen is dependent on minimizing the time between capture and release. For this reason, they were transferred daily, by helicopter, for a mid-to-late afternoon release. Consequently, this was not a public release but it is hoped to celebrate with a “Welcome to the Riflemen” event in the near future.

This is the third site to which riflemen have been translocated. The first transfer, in 2003, was from Codfish Island to Ulva Island, an Open Scientific Reserve in Paterson Inlet, Stewart Island. In 2008, a number of birds were transferred within Hawkes Bay, from Boundary Stream to Cape Kidnappers.

As there is a lack of suitable nesting cavities on Tiritiri Matangi, nesting boxes have been placed near the release site in anticipation for the next breeding season. These will be useful in monitoring the ongoing success of the species.

Facts about Tiritiri Matangi Island

Once a working farm, Tiritiri Matangi Island has been transformed, over the last 25 years, into a world renowned ecological restoration project. Around 300,000 trees have been planted by volunteers, predators removed and wildlife is now abundant. The rifleman is yet another addition to the magnificent biodiversity of the island.

Tiritiri Matangi is home to a number of endangered species including takahe, kokako, saddleback, stitchbird and tuatara.

Formed in 1988, SoTM is a volunteer organization that effectively co-manages the Tiritiri Matangi Island project with the Department of Conservation. With over 3000 members, it is one of the largest single-site volunteer organizations in the country.

Rifleman Facts

At only 8cm the rifleman is described as New Zealand’s smallest bird, although the grey warbler is about the same weight but with a longer tail. The male is a vivid green, hence the name rifleman, whilst the slightly larger female is brown. They are predominantly insectivorous and can often be seen acting like tree-creepers, i.e. ascending the trunks of larger trees, searching for food along the way.

Once widespread, they are now described as locally common from the Waikato / Coromandel to the bottom of the South Island. They are common on Little Barrier Island and also present on Great Barrier Island. As recently as 20 years ago, a remnant population was discovered in a kauri forest at Warawara, north of the Hokianga Harbour. In recent years, they appear to have become extinct on Stewart Island although a healthy population does exist on nearby Codfish Island.

The common call is a sharp, repetitive squeak, at frequencies around the upper limit of human hearing. They are not particularly loud and usually beyond the audible range for anyone with even the slightest hearing impairment.

Riflemen are part of New Zealand’s most ancient lineage of birds. The wrens were amongst the first birds to arrive in New Zealand and so the riflemen are particularly unique here.

Riflemen are not endangered but they are threatened due to the fragmentation of our forests. They are poor dispersers across water and open habitats so, once lost from a block of bush, they may well be unable to recolonise without human assistance. Also, due to very small body size, populations may crash after very cold winters etc and predators can restrict their ability to recover.

Because riflemen nest in holes in trees, their nests may be more prone to predation from the likes of rats and mice. However, it is perhaps fortunate that rifleman may not be as vulnerable to predation as some species as, unlike saddleback for example, they spend very little time on the ground and their nesting holes are often too small for predators to enter.

ENDS

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