For recordings of bird songs, call 612-673-7800, and when prompted press the following four-digit numbers:
1238 Bell's vireo
1237 black-capped chickadee
1236 common loon
1235 Northern cardinal
1234 ring-billed gull
Recordings from the Library of Natural Sounds, Cornell Laboratory of Ornithology. Try the lab's website: www.birds.cornell.edu.