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

[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.

[学科分类] 动物科学

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