For recordings of bird songs, call 612-673-9050, and when prompted press the following four-digit numbers:

5065 Baltimore oriole

5071 gray catbird

5072 sedge wren

5073 upland sandpiper

5074 varied thrush

5075 white-crowned sparrow

Recordings from the Library of Natural Sounds, Cornell Laboratory of Ornithology. Try the lab's website: www.birds.cornell.edu.