NG Field Guide to the Birds of North America, 6th edition contains the most all-new material since the first edition was published more than 25 years ago. The latest edition will include the following: 200 new art figures; first ever subspecies maps in a field guide; inclusion of extensive migrations information overlaid on species maps; field-mark labels on all artwork; text updates to include new species; reorganisation reflecting taxonomic changes in the bird community; redesign of layout for greater clarity, organisation, readability; and, increased page count (from 504 to 576) allows for flexible layout redesign and inclusion of new maps. Pagg. 576, cm 14x20, brossura.