Cyanoramphus malherbi

The orange-fronted parakeet typically feeds in the canopy of New Zealand beech trees, but will also forage in low vegetation and on the ground.[10] They are typically observed feeding in flocks of mixed species, eating various seeds, beech flowers, buds and invertebrates.[13]

During spring, invertebrates become a significant part of their diet, including leaf roller moth and fungus moth caterpillars, other Lepidoptera, and aphids.[13] They have been observed feeding on herbs and ferns on the ground, including Pratia, Oreomyrrhis colensoi, Parahebe lyallii, Leptinella maniototo and Blechnum penna-marina.[13] During mast years, beech seeds become the dominant feature of their diet.[10][13]

The Maud Island population appears to have different dietary preferences to mainland populations, eating more plant species and fewer invertebrates.[17]

Orange-fronted parakeets are monogamous and able to nest year round, but peak breeding is between December and April. They primarily nest in natural hollows or cavities of mature beech trees,[4] preferring red beech (Fuscospora fusca).[10][13][15] On Maud Island they were found to nest in Pinus radiata forests.[18]

Clutch size is around 7 eggs with an incubation period of 21–26 days.[10][18] The female exclusively incubates and the male feeds her. Nestlings fledge between 43 and 71 days, but remain dependent for 2–4 weeks.[4][18]

Their breeding is also linked to the production of beech seed during mast years.[4][10] During seeding events, and other periods where food is plentiful, they are able to produce secondary clutches, with some pairs reportedly breeding up to four times in succession.[10]

The original decline in population was most likely due to habitat destruction and fragmentation by human activity, hunting,[21] and predation from exotic species.[14][22] Hunting has ceased and their habitat is protected, but habitat fragmentation may also continue to threaten the orange-fronted parakeet.[21]

Orange-fronted parakeets evolved in isolation from land mammals, so are especially vulnerable to introduced predators. Their current decline is due to predation from stoats (Mustela ermine), rats (Rattus spp.), and brushtail possums (Trichosurus vulpecula) which target eggs and nestlings.[4][10][15][21][22] One population was reduced by 85% in 2001 due to predator irruption after a beech mast (a season of high production by southern beech).[23] Deer and possums also contribute to C. malherbi decline through forest destruction.[4][10]

Competition for food may also be a factor. Introduced birds, mice, wasps, and rats are considerably reducing invertebrate numbers, which the parakeet relies on during winter and spring.[13][21] The parakeet is however a food generalist and may compensate with other food sources, as observed on Maud Island. This dietary flexibility is promising for species recovery.[17]

Inbreeding depression and low genetic diversity may affect the viability of these small populations by reducing their capacity to adapt threats and diseases.[21][24]

The specialised nesting habitat of the orange-fronted parakeet increases its vulnerability to extinction.[18][22] The reasons for this include: (1) a single nest opening means that incubating females may be unable to escape from invading predators and will also be killed, (2) because only females incubate, predation may cause a biased sex ratio, (3) their relatively long nesting period (when compared to other passerines) increases their vulnerability to predation, and (4) the chicks tend to be noisy and therefore more attractive to predators.[22] Furthermore, in beech silviculture the trees are not given enough time to develop adequate hollows before they are harvested, thereby reducing the number of suitable nesting sites in managed beech forests.[4][15] Introduced starlings may also be outcompeting the parrot for nesting sites.[10][25]

Malherbe's parakeet is absolutely protected under New Zealand's Wildlife Act 1953.[26] The species is also listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) meaning international export/import (including parts and derivatives) is regulated.[27]

Predator management is the main strategy to reverse this species' decline.[20][21] All three mainland populations come under the "Operation Ark" initiative, which controls stoat, possum and rat populations through integrated pest management, with particular focus on reducing the effect of predator plagues.[20] These pest management strategies have worked with other New Zealand bird species to reduce predation by introduced mammals.[20][28]

Individual nest sites are also protected from predators using metal tree-trunk wraps; this has been a successful programme and only one nest out of 153 has been lost to predators since 2003.[4][10][20]

The other major conservation strategy is captive breeding programmes carried out at Peacock Springs by the Isaac Wildlife Trust, with individuals being released on predator-free islands.[4][10][20] Birds are placed in portable aviaries in the forest to acclimatise them before release.[23]

A total of 45 birds were released between 2005 and 2007 on Chalky Island, off the coast of Fiordland. The local population had increased to 150 individuals in 2009, and 100–200 by 2011, but had declined to 50–150 individuals in 2013.[4][20]

Sixty-eight individuals were released on Maud Island in the Marlborough Sounds between 2007 and 2009, but 2013 the island's population consisted of only 10–20 birds.[4][12][20]

Orange-fronted parakeets have also been translocated to Mayor Island / Tuhua in the Bay of Plenty and Blumine Island in the Marlborough Sounds; estimated population in 2013 were 50–150 and 50–100 birds respectively. These two populations, however, are not as well studied as those on Chalky Island and Maud Island.[4]

A population of orange-fronted parakeets has been established at the Brook Waimārama Sanctuary near Nelson through seven translocations (to March 2023) totalling 125 birds from several of the other populations.[29]