Close approaches and acoustic triangulation: techniques for mapping the distribution of booming Australasian bittern (Botaurus poiciloptilus) on small wetlands | Notornis and Birds New Zealand

[摘要] Reliable techniques need to be developed for monitoring the distribution and abundance of the endangered Australasian bittern (matuku, Botaurus poiciloptilus). We trialled 2 complementary methods for estimating the number of booming Australasian bitterns: acoustic triangulation from fixed listening stations, and using kayaks to quietly approach booming birds. Trials were conducted over 2 booming seasons (2011 and 2012) at Hatuma Lake, Hawkes Bay. The 2 methods gave similar estimates of the number of bitterns using Hatuma Lake (2011: 8-9 bitterns by triangulation and 9-10 bitterns by close approaches; 2012: 8-9 bitterns using triangulation and 7-8 bitterns by close approaches). We recommend using close approaches because there appeared to be less count-error or a combination of the 2 methods to estimate numbers of Australasian bitterns on small wetlands (

[学科分类] 动物科学

[关键词] booming;Botaurus poiciloptilus;census;inventory;monitoring;New Zealand