Friday, June 23, 2017

Nest site selection by sympatric orange-fronted (Cyanoramphus malherbi) and yellow-crowned parakeets (C. auriceps) in Nothofagus spp. forest: interspecific competition between two closely related species?

TitleNest site selection by sympatric orange-fronted (Cyanoramphus malherbi) and yellow-crowned parakeets (C. auriceps) in Nothofagus spp. forest: interspecific competition between two closely related species?
Publication TypeJournal Article
Year of Publication2016
AuthorsKearvell, JC, Hal, JV
JournalNotornis
Volume63
Issue1
Pagination9-17
Type of ArticleFull article
Keywordscompetition, nest sites, Nothofagus, Orange-fronted Parakeet, Yellow-crowned Parakeet
Abstract

Orange-fronted (Cyanoramphus malherbi) and yellow-crowned parakeets (C. auriceps) are sympatric congeners that are secondary cavity nesting species, with the former being critically endangered. Both currently inhabit anthropogenically-modified Nothofagus forest. We compared the characteristics of nest sites in both species and found the majority of nest site parameters (tree height, height of hole above ground, DBH, tree condition and aspect) were similar. However, orange-fronted parakeets selected nest cavities with a significantly narrower entrance, and when situated in red beech (Nothofagus fusca), nest entrances were significantly smaller in area than in yellow-crowned parakeets. As the male orange-fronted parakeet is smaller in body mass than the male yellow-crowned parakeet (only males feed nestlings when laying multiple clutches), the difference in nest hole size may simply indicate that they are capable of utilising smaller entrances. We also found that orange-fronted parakeets selected nest holes in standing dead trees more frequently and nest sites in silver beech (N. menziesii) less frequently than expected. While the lack of differences in nest site characteristics suggests some interspecific competition may be occurring between these species (i.e., they occasionally use the same nest holes), it is difficult to establish this experimentally and to determine whether these differences are artefacts of former niche separation in unmodified forest.

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