The Second Atlas of Breeding Birds in Pennsylvania comes 20 years after the first atlas. Bird populations change a lot in twenty years, so a large tome like this is a valuable resource for casual birders and expert ornithologists alike. The amount of work that went into the Second Atlas of Breeding Birds of Pennsylvania
The second edition of Birds of India (Princeton Field Guides) is expectedly fantastic and thorough. It covers India, Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and The Maldives and includes 1,375 species of birds! With so many species covered, Birds of India is still manageable in size and easy to browse and find families and species.