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MŌHUA CHARITABLE TRUST
Current Distribution

Today’s mōhua distribution

Today mōhua populations are making a comeback on predator-free islands
(Photo: Michael Eckstadt)
Today the mōhua populations are divided into three main groups- those east of the main divide, small scattered Fiordland populations (including islands), and Southland-Otago hill-country populations.

Some mainland sites such as the Landsborough Valley, the Blue Mountains and the Catlins Forest continue to sustain healthy populations of mōhua through the help of predator control. In contrast smaller isolated populations where there is no (or insufficient) predator control continue to decline and some populations have become locally extinct

Other mainland sites that have suffered population declines have since been re-stoked through translocations. The Eglinton Valley was restocked in 2010 and the Hurunui Valley mōhua population was topped up in 2008 and 2009 – both new populations are currently doing well.

The real success stories of the past decade however are the establishment of mōhua populations on predator-free off-shore islands, particularly in Fiordland. Many of these islands are now at or near carrying-capacity and have helped to ensure the security of mōhua as a species - something that mainland populations may never be able to due to the constant threat of mammalian predators.


Local extinctions – our recent history

Despite an increased conservation effort and research over the past 20 years, mōhua populations have continued to decline and their distribution has reduced. Unfortunately adequate predator control has not reached some small, fragmented mōhua populations and it is too late for some populations with local extinctions of mōhua recently recorded in the following locations:
  • Mount Stokes, Marlborough Sounds – A healthy population of 90 mōhua survived here until 1999 when a predator eruption devastated the population. 4 birds were rescued and moved to nearby Nukuwaiata Island, but it is unknown if these birds or any offspring have survived.
  • Poulter Valley, Arthur’s Pass National Park – No mōhua have been seen in this Canterbury Valley since 2006 despite stoat and mast-driven rat control.
  • Windbag Valley, South Westland - Mōhua were present on the high ridges above the valley until around 2002, one of the last places they survived in South Westland. Regular aerial pest control operations of the wider area were not sufficient for this population to survive.
  • Lake Paringa, South Westland – Mōhua were seen in the beech forests around here until the mid-1990s but there have been no records since.
  • Longwoods Forest, Southland – No mōhua have been recorded here since the mid-1990s and they are thought to be locally extinct.
  • Clinton Valley, Milford Track, Fiordland – A mōhua population was monitored on the famous Milford Track up until 2008 when numbers became too low to warrant the effort. The last birds were seen in the area in 2007.

Where and how are our mōhua populations doing today?

The table below summarises the latest known status of mōhua populations around the South Island of New Zealand, any on-going predator control or mōhua monitoring undertaken at the site and the genetic source of the population. Most mainland sites are “natural populations” meaning that the mōhua originated from the area and were not transferred there from other populations. The conservation status of the mōhua population is explained in the coloured key, although the definitions between different roles are not always clear and there may be some cross-over between them.

Table of the latest known status of mōhua populations.

Sites are listed in alphabetical order and grouped by colour by their conservation status as described in the key below. Sites supported by the Mōhua Charitable Trust are shown in the right-hand column.
Island security site:usually on predator-free or predator managed islands. Sites require prevention of pest invasion and incursion response, or on-going predator control.
Mainland security site: requiring on-going predator control and mōhua monitoring. Usually in optimal habitat sites where the habitat allows mōhua to survive with some predators.
Restoration site: places where mōhua have been transferred or are protected to reinstate or maintain the former biodiversity of the area. Sites usually too small for security sites.
Sites where mōhua are known to be EXTINCT, or have non-functional population (<10 birds), or where population unknown but expected to have disappeared from the area.
Note: Sites with no colouring are not easily fitted into any of the above definitions or there is too little information available.
Mōhua Site
Latest known status of the mōhua population (Year researched)
On-going predator control &/or mōhua monitoring
Source of founding individuals (year birds transferred)
Anchor Island, Fiordland
Widespread and increasing
Prevent pest invasion
24 birds from Breaksea Island (2002)
Bluemine Island, Marlborough Sounds
To be transferred in 2013
Prevent pest invasion
Transfer planned from Blue Mountains (2013)
Blue Mountains, Southland
Population stable (2012)
Transect mōhua monitoring
Natural pop, harvested for transfers. Genetic source of Breaksea Island birds.
Borland and Grebe Valleys, Southland
Heard to be abundant during field trip in 2010, esp in Upper Grebe Valley. Heard in 2012.
None
Natural population
Breaksea Island, Fiordland
At or near carrying capacity
Prevent pest invasion
Blue Mountains (1995), since harvested for many transfers
Burwood Bush, Southland
< 10, non-functional pop
None
Natural population
Caples Valley, Otago
Stable population (2011) but may have suffered from 2012 rat plague.
Transect mōhua monitoring. Stoat trapping in part of valley for whio protection.
Natural population
Catlins Forest, Otago
Stable population ~ 1000 birds
Previously stoat control. Now mast-driven aerial rat control. Annual mōhua monitoring.
Natural population. Harvested for transfers to Hurunui (2009) and planned transfer to Resolution Island (2013).
Centre Island, Lake Te Anau
Survived for ~ 10 years after transfer, now locally extinct.
Prevent pest invasion
Blue Mountains (late 1980s?)
Chalky Island, Fiordland
At or near carrying capacity
Prevent pest invasion
Breaksea Island (2002). Harvested for transfer to Eglinton Valley (2010).
Codfish/ WhenuaHou, Stewart Island
Present in low numbers across island
Prevent pest invasion
39 birds from Breaksea Island (2003)
Clinton Valley, Milford Track, Fiordland
EXTINCT. Last recorded in 2007.
Stoat control in valley. Monitoring until 2008.
Natural Population
Dart Valley, Otago
At least 70% mortality in 2011/12 due to predator plague
Transect and band-resight mōhua monitoring. Ground-based bait station poison operations
Natural population (harvested for transfer)
Dart Valley tributaries, Otago (Beansburn, Rockburn & Routeburn)
Scattered pockets of mōhua (to be re-surveyed in 2012)
Areas included in 1 km grid surveys for mohua. Stoat trap lines along each valley.
Natural populations
Eglinton Valley, Fiordland
At least 139 mohua, including 73 fledglings (as at March 2012)
4800ha on-going stoat control and mast driven rat control. Annual mark-resite mōhua monitoring of pairs.
< 20 remaining birds from valley; 69 birds transferred from Chalky Island (2010)
Transfer supported by the MŌHUA CHARITABLE TRUST (2010)
Fiordland National Park
Scattered populations
Some pest-control and monitoring at key sites
Natural populations (except Islands & Eglinton Valley)
Hawdon Valley, Canterbury
< 5 birds remaining (2012)
Mōhua monitoring & predator control
Natural populations
Hurunui Valley, Canterbury
Minimum of 33 mōhua present in January 2012 survey (20 adults and 13 fledglings).
Stoat control and mast-driven aerial 1080 control
Natural Population supplemented with transfers of 19 birds from Catlins (2009) and 20 birds from Breaksea Island (2008).
Two transfers supported by the MŌHUA CHARITABLE TRUST (2008 & 2009)
Iris Burn Valley, Kepler Track, Fiordland
Unknown but some birds may still survive.
No monitoring. 1 line of stoat traps down length of valley
Natural population
Joes Valley, Fiordland
Occasional birds heard
Stoat trapping
Natural population
Lake Paringa, Westland
Last seen around 1990
Natural population
Landsborough Valley, Westland
Numbers increasing until 2000; pop now probably nearing carrying capacity. 248 mōhua counted in 2011 survey.
Valley wide 5MBC surveys (1985, 91, 96-98). Annual 5MBC since 1998; Stoat trapping since 2000 and aerial 1080 operations (in 2000, 2004 & 2009).
Natural population (harvested for transfer to Resolution Island in 2011)
Makarora Valley and tributaries (Young, Wilkin etc)
34 mōhua sighted during a survey in Nov 2011.
Mōhua survey in 2011. Further surveys being conducted in 2012.
Natural population
The MŌHUA CHARITABLE TRUST have sponsored 200 predator control traps and funded additional mōhua surveys (2012)
Mt Stokes, Marlborough
EXTINCT from Dec 2000 following widespread rat eruption
Previously stoat control.
Natural population
Murchison Mountains, Fiordland
Scattered populations
Low density stoat trapping
Natural population
Nukuwaiata Island, Marlborough Sounds
5 - 20 birds (2012). Population declining.
Prevent pest invasion and annual mōhua monitoring in December
4 birds rescued from Mt Stokes (1999); 27 birds from Dart (2001)
Pigeon Island, Dusky Sound, Fiordland
Population established but migration to Resolution Is.
Prevent pest invasion
Total of 29 birds from Anchor and Breaksea Islands (2007)
Pomona Island, Lake Manapouri, Fiordland
Breeding pop established, groups >10 birds seen.
Predator-controlled island, occasional stoats, rats & mice reinvade. 5-minute bird counts bi-annually.
42 birds transferred from Breaksea Island (2011).
Poulter Valley, Canterbury
None seen since 2006
Stoat trapping and mast driven aerial 1080 control
Natural population
Resolution Island, Dusky Sound, Fiordland
In establishment phase. Mōhua sighted in 2012 following 1st transfer.
Predator-controlled island, still some stoats present
60 from Landsborough Valley (2011); Pigeon Island (self-introduced); planned transfer from Catlins Forest (2013)
This transfer supported by the MŌHUA CHARITABLE TRUST has been post-poned to 2013 due to poor weather
Rowallan Forest, Southland
Unknown
Previous monitoring
Natural population
Secretary Island, Fiordland
Widespread & increasing
Predator-controlled island, still some stoats present
75 mōhua from Dart Valley (2008)
Sinbad Valley, Milford Sound, Fiordland
< 5 individuals heard in 2011, non-functional pop
1 line of stoat control established in YEAR
Natural population
Takitimu Mountains, Southland
Some birds seen in Spence Burn (2007), Princhester and Aparima Valleys
No monitoring or predator control
Natural population
Tutoko Valley, Fiordland
< 10 birdsp
1 stoat trapping line
Natural population
Ulva Island, Stewart Island
Widespread & stable
Prevent pest invasion
Transferred
Waikaia Forest
1 heard in 2012. Last recorded during mid-80s.
Need survey for mohua.
Natural population
Waitutu Forest, Fiordland
Scattered throughout in low numbers
Aerial predator control operation in 2010
Natural population
Windbag Valley, Westland
Presumed EXTINCT. Last 2 mōhua heard on Konini Spur in 2006. Last bird seen in walking transects in 1991.
Regular 1080 operations as part of control in wider area
Natural population
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