Åldersbestämning av trädpiplärka Anthus trivialis

Abstract

Ageing criteria in Tree Pipits Anthus t. trivialis were studied and photographed at Falsterbo Bird Observatory, SW Sweden, during autumn and spring migration. Several characteristics useful for ageing were found and documented. Iris colour and the pattern on the second outermost tail-feather are valid all year, while other characteristics on wing-feathers (moult contrasts, degree of wear) are valid either in autumn or in spring/summer, depending on the moult of these feather tracts. Moult and ageing criteria are briefly commented on along with some statistics.