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Management Of The Common Myna On Mangaia, Cook Islands

Mangaia

Mangaia is the second largest and most southerly of the Cook Islands and is the oldest island in the Pacific. It has a central volcanic plateau and, like many of the southern islands in the Cooks, it is surrounded by a 60 m high ring of cliffs comprised of fossilised coral or makatea. The island has a population of around 600 people.

The Invasive Species

Mynas are regarded as pest birds in most Pacific countries and are recognised globally as an invasive species where they are a nuisance in towns and villages. Mynas have been introduced all over the world, mainly in an effort to reduce insect populations in agricultural areas. However, they have been found to effect native biodiversity by competing for nesting holes, preying on chicks and eggs and evicting small mammals. In 1996 the common myna (Acridotheres tristis) population on Mangaia Island was estimated at 8,000–10,000 birds with most found in arable areas of the island.

Biodiversity Values

The myna may pose a threat to Mangaia’s biodiversity, in particular to the endemic Vulnerable (IUCN Red List, 2004) Mangaia kingfisher (Todiramphus ruficollaris). The Mangaia kingfisher has an estimated population of only 400-500 birds. Anecdotal evidence indicates that the kingfisher cannot breed successfully outside the small areas of Barringtonia asiatica forest on Mangaia because of interference from the myna. It is important to enable the kingfisher to breed more successfully in the arable areas of Mangaia, presently occupied by the myna, by reducing interference and competition from the myna.

Project Description  

Taporoporo’anga Ipukarea Society (TIS), an environmental Non-Governmental Organisation in the Cook Islands, has proposed a project to eradicate the invasive common myna from Mangaia.

A Feasibilty study team made up of Ian Karika, Ewan Cameron (TIS representatives), Gerald McCormack( Cook Islands Natural Heritage Trust), John Parkes ( Maanaki whenua - Landcare Research ) and Bill Nagle (PII) visited the island from 10 to 21 June 2006.  They were joined on 17–19 June by James Atherton of Conservation International, Apia, Samoa. 

The purpose of the feasibility trip was to:

• complete the myna assessment and to consult again with Mangaians on their level of engagement with the project, particularly on whether they wanted to eradicate the mynas.
• ascertain social acceptability of potential control methods, and on general constraints on where acceptable methods might be used to avoid non-target animals or for human safety reasons
• explore the technical feasibility and methods for eradication

Please click on these links

'Feasibility Plan to Eradicate Common Mynas (Acridotheres tristis) from Mangaia Island, Cook Islands' to view a copy of the Landcare Research report.

Eradication of Common Mynas. Parkes J 2006, KarareheKino

PII Contact

Bill Nagle - (w.nagle@auckland.ac.nz)

Please click on coloured text for links to relevant information.

Last updated 27 May 2008