Between 4,000 and 4,500 different types of songbirds can be found around the world. Male birds sing to attract females and to warn rivals to keep out of their territory. They are identified by their highly developed vocal organs, although some, like the crow, have harsh voices, and others sing rarely, or not at all.

All songbirds are classified as perching birds. With three toes that point forward and one that points backward, they can grip branches, grasses, or telephone wires with ease. The ten in this set are the western meadowlark, mountain bluebird, western tanager, painted bunting, Baltimore oriole, evening grosbeak, scarlet tanager, rose-breasted grosbeak, American goldfinch, and the white-throated sparrow.