Conservation and genetics of New Zealand parakeets

Abstract

Recent genetic analysis of New Zealand Cyanoramphus parakeets has direct implications for conservation management. A subspecies of Yellow-crowned Parakeet, Forbes's Parakeet C. auriceps forbesi, is genetically distinct from mainland Yellow-crowned Parakeets C. a. auriceps and should be elevated to species status. Even amongst mainland populations of Yellow-crowned Parakeets there was extensive genetic diversity. Interspecific hybridization is a major concern of Cyanoramphus conservation. The near-extinction of Forbes's Parakeets by genetic swamping through hybridization with Chatham Islands Red-crowned Parakeets C. novaezelandiae chathamensis has been averted by active management, involving culling of hybrid and Red-crowned Parakeets and habitat enhancement. Despite two decades of hybridization between these species a distinct Forbes genetic type still exists, probably due to a tendency for hybrids to backcross with Red-crowned Parakeets. Hybridization between Cyanoramphus species may also be a problem in other highly modified habitats, such as parts of the Auckland Islands. More information is needed to determine the extent of this problem. Captive populations include a significant proportion of interspecific hybrids and therefore should not be used as founder stock for releases into the wild, as has been done in the past. The Orange-fronted Parakeet should be reinstated as a separate species, Cyanoramphus malherbi, rather than a colour morph of Yellow-crowned Parakeet, at least until conclusive evidence is available to resolve the question of its taxonomic status. The conservation of this very rare species (and indeed all species of Cyanoramphus) has been severely handicapped by lack of scientific information on which to base management decisions.