Az erdei szalonka (Scolopax rusticola L.) tollváltása, a tollazat alapján történő kormeghatározás lehetőségei

Bende, Attila (2023) Az erdei szalonka (Scolopax rusticola L.) tollváltása, a tollazat alapján történő kormeghatározás lehetőségei. MAGYAR VÍZIVAD KÖZLEMÉNYEK (37). pp. 45-58. ISSN 1416-1389

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Abstract

This study summarises the most important data in the literature on the feather changing of woodcock. This is supported by a set of recommendations for an easy-to-use field practice, summarising the typical age stamps by age group. This is an important topic, because there is no detailed literature available in Hungarian on feather changing and age determination for domestic practice. For ringing work in Hungary and for the analysis of data sets evaluated by sex and age in wildlife studies, the age of birds is an indispensable knowledge, but in this respect, it is sufficient to distinguish between adult and juvenile specimens, and a finer-scale grouping is not common practice in Hungarian woodcock research, although the criteria for this classification are also presented in this paper for the sake of completeness. The distinction between juvenile and adult age classes is based on the degree of moulting, and the examination of this for each group of feathers in the wing, for which the following stamps should be considered: In juvenile specimens, the large upper wing coverts are short and narrow, with a typically dull reddish-brown to brownish tint, the black parts also dull, and the down at the base of the feathers less developed. In juvenile secondaries, the rusty, cinnamon-brown striping near the shaft of the feather is distally pointed and reduced to a triangular dark patch. The characteristic light spot on the underside of the tail-feathers is a dull shade of greyish white, with a more diffuse light brown pattern than on the adult plumage. (Figure 5). First-year birds can be distinguished from older birds by the wear and shape of the tips of the 8th to 10th primaries, which are not shed during juvenile moulting. In addition to their weariness, it should be noted that they are distinctly pointed, not concave, and their edges are usually not bone-coloured. Primaries have a wide edge (1,5-2,5 mm), which is usually the same brownish colour as the ridge pattern. The contrast can be stark for the greater coverts, because birds that hatch early in the breeding season have time to shed all the greater coverts before the autumn migration, so these feathers already reflect adult characteristics. During the first wintering, the tips of the 5th and 6th primaries are slightly convex, and the wing covers have a sugar-loaf tip. The light patch at the base of the tail-feathers is white at this stage, the brown pattern is well defined and not diffuse. Adults moult between July and September (primaries, secondaries, tertials and tail-feathers), so their plumage is free from wear in autumn and winter, compared to the worn, poorer condition of the first-year birds with unmoulted feathers. The tip of the 5th and 6th primaries in adult birds is broadly flattened and slightly concave. The tips of primaries have narrow edges (<1,5 mm), usually white with a bone colour. All greater upper-wing coverts are reddish brown. and light brown with a light pattern. Fairly long and broad, with well-developed down at the base. The greater under-wing coverts (typically the primary coverts of primaries and secondaries) are greyish with broad, “angular” tips. Occasionally adults do not fully shed juvenile wing feathers, so these can also be seen in second-year birds (Figure 6).

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