For recordings of bird songs, call 612-673-7800, and when prompted press the following four-digit numbers:

1201 American tree sparrow

1202 black-necked stilt

1203 golden-crowned sparrow

1204 marsh wren

1205 red-breasted nuthatch

1206 white-winged crossbill

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