Observations on the Birds of Argentina, Paraguay, Uruguay, and Chile

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The successful operation of the Federal Migratory Bird Treaty in according protection, hitherto uncertain, to migratory game and insectivorous birds, with resultant increase in many species, led naturally to inquiri...