Friday, May 26, 2017

Distribution of sympatric orange-fronted (Cyanoramphus malherbi) and yellow-crowned parakeets (C. auriceps) in the South Branch Hurunui, New Zealand, prior to a catastrophic population crash

TitleDistribution of sympatric orange-fronted (Cyanoramphus malherbi) and yellow-crowned parakeets (C. auriceps) in the South Branch Hurunui, New Zealand, prior to a catastrophic population crash
Publication TypeJournal Article
Year of Publication2016
AuthorsKearvell, JC
JournalNotornis
Volume63
Issue3-4
Pagination167-172
Type of ArticleFull article
KeywordsCyanoramphus, distribution, parakeet, reintroduction, vegetation
Abstract

The valley of the South Branch of the Hurunui River, prior to 2001, held a dense population of the orange-fronted parakeet (Cyanoramphus malherbi). However, a rat plague in 2001 reduced this population by ~85%. In preparation for a restoration program of this species in the Hurunui valley, I analysed the distribution of sightings of orange-fronted parakeets, as well as the congeneric, yellow-crowned parakeet (C. auriceps) prior to the population collapse. My objective was to identify the areas and types of habitats used by each species. A vegetation survey showed significant differences between different parts of the valley floor study site, and this appeared to be reflected in the distribution of orange-fronted parakeets. Both species had significantly different distributions, and orange-fronted parakeets were recorded most frequently within forests growing on the river fan, an area characterised by mature red beech (Nothofagus fusca) and areas of dense regenerating mountain beech (N. solandri var. cliffortioides). While the valley has been subject to anthropogenic modification since the 1850’s, it still contains a relatively intact beech forest. My observations on the historic distribution of orange-fronted parakeets suggest this valley is still capable of supporting a large population of the species. However, the success of any re-introduction program is likely to depend upon continued preventative and reactive predator control, as well as a release programme that introduces enough individuals to prevent severe bottlenecks.

AttachmentSize
PDF icon Full article903.54 KB