DIJK AJ VAN (1980) Observations on the moult of the Black-tailed Godwit Limosa limosa. LIMOSA 53 (2): 49-57.
In the northern part of the Netherlands the moult of Blacktailed Godwit Limosa Iimosa was studied during the period May up to August 1976-79. Three methods were used: (a) observations on moult in the field ; (b) collection of newly shed feathers; (c) examination of museum material. Next to it attention has been paid to the identification of feathers, to primary moult in connection with number of birds on the nocturnal roost, breeding season, occurrence of feeding flocks and migration. During the end of May till July-August both birds, with and without primary moult, were counted on the roost the Dwingelose Heide. Within this period most of the Black-tailed Godwits moult primaries 1-6/7 descendently, secondary I and a part of the tail feathers. Before leaving the Netherlands in July and August, the moult of these feathers will be suspended and completed elsewhere later on. Most of the body feathers and coverts are moulted within the period of primary moult. The onset of the primary moult is observed between the end of May and the end of July. Feeding flocks are formed from the end of May. The first juveniles have been seen between 2 and 15 June and the last juveniles on the breeding grounds between 10 and 28 July. The percentage of birds without primary moult on the roost in the period when most of the juveniles become fledged and before the first adult Black-tailed Godwit stops the primary moult are in the same order as the percentages of juveniles in the feeding flocks. So probably these birds without primary moult are mainly juveniles. This may give an indiciation of reproduction success: in 1976 and 1979 the reproduction success was Favourable (21-49% and 29-45%); in 1977 and 1978 unfavourable (20-33% and 8-19%).
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