Productivity and survival within 2 declining populations of brown teal ( Anas chlorotis ) | Notornis and Birds New Zealand

Notornis

Williams, M¹ 

关键词: Anus chlorotis;    breeding;    brown teal;    New Zealand;    Northland;    population;    survival;   

DOI  :  

学科分类：动物科学

来源: Ornithological Society of New Zealand Inc.

【 摘 要 】

Brown teal (Anas chlorotis) populations at Clendon Cove and Tutaematai in Northland, New Zealand, declined catastrophically between 1993 and 1995, from 31 pairs to 1 and from 22 pairs to 8, respectively. Mean productivity was 1.8 fledglings pair1 in both populations. Fledgling survival was almost nil with only 1 of 51 identifiable fledglings surviving to recruit into 1 population. Almost all fledgling mortality occurred within 3 months of independence. Annual adult survival was 15% at Clendon Cove and 43% at Tutaematai and most deaths occurred in October-December, immediately after breeding. At Clendon Cove, significant mortality also occurred in autumn. Destruction of breeding and refuge habitat by cattle seeking moisture during periods of drought was identified as a significant cause of decline.

【 授权许可】

Unknown