A STUDY OF THE BLACKBIRD TURDUS MERUL A IN NEW ZEALAND.

摘要: Summary 1 New Zealand Blackbirds tend to be bigger than British. 2 The ratio of males females was 2: 1 and first-winter second-winter or older 4–6: 5-4 in a normal winter population. 3 The moulting season at Dunedin January April inclusive, but some first-year birds had partial moult August, September early October. 4 Plumage is classified into five colour-groups; most were “darkish brown”. 5 The black beaks change orange by the end August; beak-colour considered variable genetical character. 6 Seasonal variation size gonads, its relation behaviour, are discussed. 7 Songs calls described related behaviour. The total song-period New 10½ months. 8 Territory established area averages 1^ 2 acres. 9 Pair-formation takes place before July full song plays no part this. 10 The roosting site for an individual constant whether territory not. Roosting awakening times averaged 20 minutes after sunset 43-5 sunrise. 11 Nesting begins late August ends December. Resumption breeding desertion discussed. 12 The rhythm activity nest during incubation relationship incubating female described. 13 Fertile eggs lost approximately 0–1 gm. weight per day incubation. Nestlings increased weight, from hatching maximum, 13-3, 11-2 11-8 respectively, decreased leaving nest. 14 Fledging success lower nests studied it Great Britain.