Birds of North America Online ~ New Ways to Birdwatch @ AADL
A project of the Cornell Lab of Ornithology, Birds of North America Online includes contributions from researchers, citizen scientists, reviewers and editors and image and video galleries showing plumages, behaviors, habitat, nests and eggs, and more. BNA now features recordings of the songs and calls of their species from the extensive collection of Cornell's Macaulay Library of Natural Sounds.
You can access BNA Online 24-hours a day from home through our Database Page. I like putting in keyword terms like "black billed" or "blue throated" and seeing the results. Amazing what great background music bird calls provide to a day indoors.