C-2029 : Winter nesting of the birds near north pole in the Northern Hemisphere–Yakutia/Russia

Abstract

In winter on Yakutian taiga 10 species of birds nest (3.7% breeding fauna). Evening temperatures reach −20 ÷ 30 C°. In March Bubo bubo nest (4 nests) and in April Surnia ulula (4 nests). In March-May the egg-laying of Loxia leucoptera begins (50.0–66.7% clutches; n = 10), at the end of March to early May, Corvus corax (93.2–100.0; 47) and Perisoreus infaustus (75.0–87.6, 93). In April and May egg-laying starts in Strix nebulosa (52.9; 17), Nucifraga caryocatactes (33.3–100.0; 13), Accipiter gentiles (0–33.3; 4), and Haliaeetus albicilla (33.3; 3), and stretches up to July for Acanthis flammea (1.0–27.3; 637). In the middle taiga in winter nesting is earlier in the calendar and phenological periods than in other parts of their range, 87.6% pairs of the Siberian jay (n = 89). Also here their clutches are larger (2–5, average 3.99 ± 0.06 eggs; n = 90). In the woods of valleys species begins egg-laying earlier than in the watersheds – the end of March (22.7%; n = 44) versus the beginning of April (38.5, 26), has a larger clutches – 4.13 ± 0.09 (n = 40) versus 3.75 ± 0.1 (28), and nesting mostly on the trees (84.5%; n = 73), and watersheds – on the willows (67.2, 70). There are other mechanisms that allow to species to breed at winter temperatures and in various landscapes. Pairs are constant and strictly territorial, nest on the trees and shrubs (n = 192) at a height of 0.5–8.0, on average, 1.6 (willow) −2.9 (pine) m, mainly on south side (50.0 %). Feathers, down and rag compose up to 22.8 % weight of the nest (n = 5), a supporting part (dry twigs) – 63%. The numbers of the population in the site of the watershed taiga (10.6 km2) in spring and autumn are, respectively, 59–84 and 55–87 individuals. In November 2012 residents amounted to 71.9%, immigrants – 18.7 (n = 64). In the autumn of 2009, the ratio female and male (n = 25) was equal, and for juv (29) the number of males was larger (1:1.5), but for the year it aligned for them also. On eggs females spend an average of 96.7% of the day. Chicks hatch for 1.5 days on average, they are fed in the end of April, from 5:25 to 19:45 h, after 1.5 h.