Monitoring mohua (yellowhead) populations in the South Island, New Zealand, 1983–93

摘要: Abstract The mohua (or yellowhead, Mohoua ochrocephala) is an endangered hole‐nesting passerine which now absent from >75% of its former range. This paper describes 11 year monitoring programme, was set up to survey 14 populations at 12 key sites throughout the range mohua, in order document pattern population change and provide early warning likely local extinctions. Between 1983 1993, one became extinct. Five declined significantly, three these were on verge extinction by 1993. One increased, seven did not although a declining trend recorded five these. Six crashes coincided with irruptions stoats (Mustela erminea) following heavy beech (Nothofagus) seeding.