|Scientific Name:||Cyanoramphus malherbi|
|Species Authority:||Souancé, 1857|
|Taxonomic Notes:||Cyanoramphus auriceps (Sibley and Monroe 1990, 1993) has been split into C. auriceps, C. forbesi and C. malherbi following Boon et al. (2000). 'Malherbe's Parakeet' is used as the common name for C. malherbi because 'Orange-fronted Parakeet' as used in BirdLife International (2000, 2004) is taken by Aratinga canicularis.|
|Red List Category & Criteria:||Critically Endangered A2bce ver 3.1|
|Contributor(s):||Greene, T., Hitchmough, R., Kearvell, J. & van Hal, J.|
|Facilitator/Compiler(s):||Benstead, P., Bird, J., Butchart, S., Harding, M., Khwaja, N., McClellan, R., Symes, A. & Taylor, J.|
This species is listed as Critically Endangered because, subsequent to serious declines since the 1800s, it underwent a population crash following rat invasions in 1990-2000, and it now has a very small population that has declined during the last decade. However, the global population is now increasing owing to successful translocations onto four predator-free islands, and control of predators in its South Island range, and if this trend continues it may qualify for downlisting once the number of mature individuals in the population is clarified.
Cyanoramphus malherbi is known from three valleys in the South Island of New Zealand which are all known to support small breeding populations: the South Branch Hurunui River valley, Hawdon River valley and the Poulter valley, North Canterbury, plus four translocated island populations. Birds were sighted in the North Branch of the Hurunui River valley in 2004 and 2005, and a lone male was seen in the Andrews valley in 2007 (J. C. Kearvell in litt. 2012). A sighting of a single bird from the Eglington Valley, Southland (1990-1991) was reported. Unconfirmed sightings from three further valleys during the 1990s are known. In 1999-2000, the population crashed from perhaps 500-700 birds to a rough estimate of 100-200 as a result of ship rat irruptions in two successive summers (J. van Hal in litt. 2008, 2009). The population since appeared to stabilise at low levels since then and may have increased owing largely to translocations. It was once present in the North, most of the South, and Stewart Islands, but range contraction continued into the 1990s, with searches failing to find populations present in the 1960s and 1980s (Higgins 1999).
In the largest population, the Hawdon River valley, there were perhaps 70-200 individuals in 2013 with an apparent decrease in numbers (J. C. Kearvell in litt. 2013). Declines were also apparent in 2013 in the Poulter valley where there may be 40-80 birds (J. C. Kearvell in litt. 2013). In the South Branch Hurunui River valley numbers were thought to be very low in 2013, with as few as 20-40 birds (J. C. Kearvell in litt. 2013). Translocations to Chalky Island in Fiordland began in December 2005 and have proved successful, with birds breeding and the population expanding to utilise all corners of the island (Anon. 2007), with over 150 birds estimated in 2009 (J. van Hal in litt. 2008, 2009) and 100-200 individuals in early 2011; a total of 45 birds were released between 2005-2007 (J. C. Kearvell in litt. 2011, 2013). An apparent decline has recently been detected in the Chalky Island population, accompanied by an increase in C. auriceps, and in 2013 there were perhaps 50-150 mature individuals of C. malherbi (J. C. Kearvell in litt. 2011, 2012, 2013). From 2007-2009 translocations (involving a total of 68 birds) also took place on Maud Island, with successful breeding recorded and perhaps over 50 birds in 2009 and 60-100 in early 2011, although in early 2012 there were thought to be only 30-50 mature individuals, and there were perhaps only 10-20 mature individuals in two small areas in 2013 (T. Greene in litt. 2007, J. van Hal in litt. 2008, 2009, J. C. Kearvell in litt. 2011, 2012, 2013). In addition, translocations to Tuhua Island have been taking place since December 2009, with 95 birds released by April 2013; there has been little monitoring but in 2013 birds were heard for the first time away from the Green Lake area and the total population may have been 50-150 mature individuals (J. C. Kearvell in litt. 2013). Translocations have now also been carried out on Blumine Island in the Marlborough Sounds, where 61 birds were released in 2011/2012; two nests and several immature birds were noted in 2013 when there were perhaps 50-100 birds there in total (J. C. Kearvell in litt. 2012, 2013).
The apparent recent downward trend on the mainland may be tempered by slow increases on all islands apart from Maud (J. C. Kearvell in litt. 2013). Overall, the global population may have numbered 290-690 individuals in early 2013, with the mainland populations estimated to total 130-270 individuals and the island populations totalling 160-420 individuals; however, all figures should be treated with a high degree of caution since accurate population estimates are extremely difficult to obtain, owing to difficulty in separating this species from sympatric C. auriceps, as well as the rarity and difficulty of locating the species (J. C. Kearvell in litt. 2011, 2013, T. Greene in litt. 2012).
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Although the population numbered several hundreds prior to 2000, a prolific increase in the population of rats and stoats within its restricted South Island range induced a rapid population decline and the total population has remained well below its previous levels. Successful translocations on four islands have boosted the population of this species, but decreases may have continued on the mainland. Overall, the global population may have numbered 290-690 individuals in early 2013, with the mainland populations estimated to total 130-270 individuals and the island populations totalling 160-420 individuals, although obtaining accurate population estimates is extremely challenging for the species (J. C. Kearvell in litt. 2013). Although the species is a precocious breeder that is capable of nesting at an early age, it is still uncertain what proportion of the birds now present on Chalky Island, Maud Island, Tuhua and Blumine have bred successfully and can therefore be classified as mature individuals. Accordingly, the number of mature individuals is precautionarily retained as 50-249, and the number of individuals placed in the band 250-999.|
|Habitat and Ecology:||It is restricted to Nothofagus beech forest, although it may not have been so historically. It requires mature trees with natural hollows or cavities for nesting. Monitoring has revealed that 80% of nests are in mature living trees, with the remaining 20% in dead trees (J. C. Kearvell in litt. 2012). Of those nests found in mature trees, 68% are in red beech Nothofagus fusca. Breeding is linked with the irregular seeding of Nothofagus when numbers can increase substantially. In mast years, many pairs will lay a second clutch, and some may lay a third clutch, with breeding continuing through the austral winter. First clutches may average more than eight eggs, with second clutches averaging over seven in 2011. A recent study on Maud Island has shown that birds form pairs at around seven years of age, and nest in a variety of natural cavities where beech is unavailable (J. Kearvell in litt. 2011, 2012). It feeds on seeds, fruits, leaves, flowers, buds and invertebrates (Kearvell 1999).|
The impact of introduced predators, principally stoats Mustela erminea and rats Rattus spp., is likely to be the primary cause of decline (Higgins 1999), with recent population crashes being due to rat irruptions. The species's hole-nesting behaviour leads to a reduced ratio of females in the population due to predation of birds on the nest (Elliott et al. 1996). Silviculture of beech forests aims to harvest trees at an age when few will be mature enough to develop suitable cavities, so sufficient nest holes are unlikely in managed beech forest (Kearwell 2002). The species forages in low-growing shrubs and such lower forest levels have been subject to heavy browsing by cattle, deer and possums, altering the forest structure (Duncan and van Hal 2004). The population on Chalky Island may suffer competition from C. auriceps (J. C. Kearvell in litt. 2011). Population growth in island populations, especially on Maud Island, may also be limited through predation by falcons (Falconidae), and displacement of two nesting pairs by introduced Common Starlings Sturnus vulgaris has now been documented; the overall impact of this recently-identified threat is uncertain, but may be minimal (J. C. Kearvell in litt. 2012, 2013).
In 2008, it was confirmed that native Red-crowned Parakeets C. novaezelandiae on Little Barrier Island were suffering from psittacine beak and feather disease (PBFD). The virus has been sequenced and appears very similar to the strain found in Crimson Rosella Platycercus elegans, in which the disease is known to be endemic within the captive population. In 2009, some individuals of C. malherbi on Maud Island were showing some symptoms consistent with PBFD. In reaction, testing of the entire captive population has been undertaken, as well as more limited sampling of individuals in all three island populations, as well as other parrot species. Results indicate that antibodies for PBFD were detected in C. malherbi from both Maud Island and the captive-rearing unit; notably in the latter case antibodies were found in the C. novaezelandiae foster parents (J. C. Kearvell in litt. 2011), and the disease has now been found in C. auriceps in the Eglington Valley, Fiordland (J. C. Kearvell in litt. 2012, 2013). Monitoring for the disease in the captive population continues and it is hoped that the unit will soon be declared disease-free (J. C. Kearvell in litt. 2013). C. malherbi at all three Mainland sites and on Tuhua were seen to be in very poor feather condition in 2012/2013, with a major infestation of Dermanyssus mites having occurred on Tuhua. On the mainland, mites were suspected but immunosuppression may also be involved, either because of small population size and/or because of post PBFD issues (J. C. Kearvell in litt. 2013).
Conservation and Research Actions Underway
CITES Appendix II (1981). Hawdon and Poulter valleys are located within Arthur's Pass National Park and the Hurunui South Branch is in Lake Sumner Conservation Park (J. van Hal in litt. 2008, 2009). Monitoring and conservation of this species is problematic given the difficulty in separating it from C. auriceps. The Hurunui population is contained within a "mainland island" which aims to protect and restore two river valleys through integrated pest management, including minimising numbers of M. erminea. Monitoring of nests will verify whether this is allowing numbers to stabilise and expand. The Hawdon population received M. erminea control only during plague years, which occur, on average, every four years (J. C. Kearvell in litt. 1999). However, following the dramatic decline in the parakeet population after failure to effectively control predators, rat poisoning and stoat trapping are more extensive within the Hurunui "mainland island" (Keey 2004). All three valleys are now part of the "Operation Ark" initiative targeting rats and stoats in South Island beech forest sites. The control of M. erminea is now continuous, whereas control measures against rats are implemented when populations reach trigger points (J. C. Kearvell in litt. 2011, 2013). Every nest found is also individually protected with tin tree wraps (to prevent access by predators), ground predator traps and possum traps (J. van Hal in litt. 2008, 2009), and since 2003 only one nest out of 153 has been lost to invasive predators (J. C. Kearvell in litt. 2013).
Since 2003, the captive facility at Isaacs Construction Wildlife Centre, Peacock Springs (Christchurch), has released, in conjunction with Department of Conservation, a total of over 250 C. malherbi (J. C. Kearvell in litt. 2012). Since 2005, individuals have been translocated to Chalky Island in Fiordland, which is free from predators (Duncan and van Hal 2004). The reintroduction of birds to Maud Island has been underway since 2007, and wild-bred birds are now nesting on the island. Translocations to Tuhua Island have been taking place since December 2009, and in early 2011 it was expected that all birds produced in the next captive breeding season would be released there to provide a sufficient founder population (J. C. Kearvell in litt. 2011). Translocations have also been carried out on Blumine Island (J. C. Kearvell in litt. 2012). A second captive-breeding group was being set up at Mount Bruce but has been discontinued due to a lack of capacity (J. C. Kearvell in litt. 2013). A study has been initiated to assess the genetic diversity of the remnant mainland population, with the aim of ensuring that any new founder populations on islands are as genetically diverse as possible, has been completed (J. C. Kearvell in litt. 2013). An analysis of breeding data is also due to be started. A comprehensive testing programme for Psittacine Beak and Feather Disease (PBFD) is currently underway on parrots throughout New Zealand (T. Greene in litt. 2012) and continued in 2013 (J. C. Kearvell in litt. 2013).
Conservation and Research Actions Proposed
Develop a technique to accurately monitor numbers. Continue to study the species's breeding biology and ecology. Stabilise and increase numbers in the mainland valley populations through predator control, and monitor effectiveness. Train people in the identification of the species (J. C. Kearvell in litt. 1999). Following the success of translocations to Chalky Island and Maud Island, establish further populations on predator-free offshore islands and develop captive breeding programmes to assist with this. Closely monitor the threat from PBFD (J. C. Kearvell in litt. 2011). Continue research into methods of controlling introduced predators (J. C. Kearvell in litt. 2012).
|Citation:||BirdLife International 2013. Cyanoramphus malherbi. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 25 October 2014.|