LEBRET T (1961) Request for cooperation. Research on first-year and perennial Common Shelduck Tadorna tadorna. LIMOSA 34 (1): 168-168.

At Common Shelduck are birds from September to July first dav field still be distinguished from perennial birds. Ie they have a clearly visible white band at the end of the small feathers. which is also part of large feathers still continues. In perennial Shelducks the whole wing mirror solid black. Note the image of a perennial Shelduck in Bird flight in the Guide. Piaat next 13 p. 76 and the wing of a first Shelduck in Field Characteristics of Waders. Swans. geese and Ducks, L. Tinbergen. Common Shelduck Tadorna tadorna

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