The Chatham parakeet (Cyanoramphus forbesi), also known as Forbes' parakeet, is a rare parakeet endemic to the Chatham Islands group, New Zealand. This parakeet is one of New Zealand's rarest birds and is classified as Vulnerable on the IUCN Red List, as a result of a range of threats to the species survival, including habitat loss, predation, and hybridization. A number of conservation methods have been employed to assist the recovery of this species, and currently the population trend is considered stable.
Taxonomy
Walter Rothschild described the species in 1893.
"Chatham parakeet" has been designated the official name by the International Ornithologists' Union (IOC).
Forbes’ parakeet is one of ten species in the genus Cyanoramphus, a genus consisting of parakeets from New Zealand and surrounding islands. Originally classified as a distinct species (Cyanoramphus forbesi) Forbes’ parakeet was later thought to be a subspecies of the Yellow-crowned Parakeet Cyanoramphus auriceps and was renamed Cyanoramphus auriceps forbesi. Forbes’ Parakeet has since been the subject of a range of molecular tests to determine the correct classification of the bird. These tests have resulted in C. forbesi being reinstated as a separate species to C. auriceps, on the basis of genetic variations, as well as morphological differences such as size and vocalisations.
Hybridisation
Mitochondrial DNA analysis and microsatellite genetic markers have both indicated a high degree of hybridisation between Forbes’ parakeet and the Chatham Island Red-crowned Parakeet (Cyanoramphus novaezelandiae chathamensis), which is also found on Mangere Island in the Chatham Islands.
Description
Forbes’ parakeets are medium-sized parakeets, with long tails and orange-red eyes. Plumage is bright green, with a red band across the forehead (but not reaching the eyes) and a yellow forecrown. The lores are also green, and the bird has some red plumage on the sides of the rump, and violet-blue outer primaries and wing coverts. The female parakeet is slightly smaller than the male, which is also reflected in her smaller bill size.
Forbes’ parakeet is easily distinguished from the Chatham Island Red-crowned Parakeet by its golden-yellow forecrown, as like its name suggests the Chatham Island Red-crowned parakeet has a red forecrown. It is also distinguishable from the Yellow-crowned parakeet (Cyanoramphus auriceps) despite looking quite similar, as C. auriceps is not found in the Chatham Islands.
Distribution and habitat
Forbes’ parakeet is found only on Mangere and Little Mangere (Tapuaenuku) Islands in the Chatham Islands group. The Chatham Islands are sovereign land of New Zealand, and lay to the South-east of Wellington.
Historically, Forbes’ parakeet was documented in the 1800s to have travelled to nearby Pitt Island and southern Chatham Island. The species was extinct on Mangere Island by 1930 as a result of significant deforestation. However, the species persisted on Little Mangere Island, until recolonizing Mangere Island in the 1960s after the removal of introduced species (such as cats, rabbits and grazing livestock) and after the native vegetation had a chance to grow back.
The parakeet is found in dense forest and scrub, and utilizes tree hollows and rock crevices to nest.
Conservation
Forbes’ parakeet is absolutely protected under New Zealand's Wildlife Act 1953. The species is also listed under Appendix I 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.
Forbes’ parakeet has faced a number of threats to its survival, with the population once falling as low as 20–30 individuals. These threats include deforestation and habitat destruction, the introduction of predators, and the fact that the entire population is confined to two small islands in the Chatham Islands group-Mangere and Little Mangere Islands, which are only 112ha and 16ha respectively.