The Cornell Lab of Ornithology recently published more than 7,500 hours of bird calls from nearly 9,000 birds. The recordings are published on the Macaulay Library site. You can browse for recordings recommended by Macaulay Library or you can search for a bird by name. When you find a recording you can also see a Google Map of where the recording was made. While the recordings cannot be downloaded for free they can be heard for free. Click here for an example.
Applications for Education
The Cornell Lab of Ornithology's Macaulay Library's archive of bird calls could be a nice resource for science teachers. If you're looking for a spring project that your students can do outside consider having your students listen to some of the recordings of birds that could be found in your area. Then have students try to keep a log of when they hear a bird call that matches what they've heard in the recordings. Those of us in the north could have students document when they first hear a migratory bird that has returned from the south.
The Cornell Lab of Ornithology has a YouTube channel that offers some nice mini documentaries about birds. I've embedded a video about Snowy Owls below.
H/T to Open Culture.