The second census of Chatham Island shag and Pitt Island shag - are numbers declining? | Notornis and Birds New Zealand

[摘要] A census of Chatham Island shag (Leucocarbo onslowi) and Pitt Island shag (Strictocarbo featherstoni), both endemic to the Chatham Islands, New Zealand, was conducted during their 2003/04 breeding season. Totals of 271 pairs of Chatham Island shags and 547 pairs of Pitt Island shags were recorded. Compared with the only previous survey (in 1997/98), numbers of both species were significantly lower. This decline most likely reflects broad scale marine changes affecting the birds' food supply. Alternatively, it may suggest variability in the timing of breeding between seasons.

[学科分类] 动物科学

[关键词] census;Chatham Island shag;distribution;Leucocarbo onslowi;Pitt Island shag;population size;Strictocarbo featherstoni