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This guide introduces new aids for identifying over 40 species of ducks, geese and swans. One identifies the species of duck in hand; the other assists in determining the species in flight. A duck in hand can be identified by the size and shape of its bill. Charts are provided for the user to match a bill in hand with the outlines of the particular species. The full size and shape of the bill is shown along with information to solidify selection. To aid in-flight identification, this method introduces a new dimension - Levels (strata or layer) of flight that the various species fly in over open water, and these are divided into four distinct levels. The study and use of this dimension, coupled with flock characteristics and species markings, will aid your in-flight identification.
- Format: Pocket/Paperback
- ISBN: 9780811729826
- Språk: Engelska
- Antal sidor: 75
- Utgivningsdatum: 1986-11-01
- Förlag: Stackpole Books