Age determination of Jack Snipe by plumage characteristics
60 – 65
1 April 17
Michel Devort, Gilles Leray, Yves Ferrand
Office National de la Chasse et de la Faune Sauvage, Direction de la recherche et de l’expertise – Unité Avifaune
migratrice, Parc d’Affaires La Rivière, 8 Bd Albert Einstein – CS 42355, 44323 Nantes Cedex 3, France
We develop a method to age Jack Snipe Lymnocryptes minimus during autumn using outer tail feathers. This method was tested by also ageing birds through the presence/absence of the bursa of Fabricius. The pattern on the tip of the outer tail feathers allowed reliable age discrimination of more than 80% of adults and juveniles sampled. Most adults had a single pale spot on the external side of the outer tail feather whereas juveniles displayed a narrow black line separating two pale spots. Overall, we describe two adult patterns and four juvenile patterns. The validity of the resulting ageing key was tested and confirmed using volunteer ringers.