Explaining Goose Music

I heard of a boy once who was brought up an atheist. He changed his mind when he saw that there were a hundred-odd species of warblers, each bedecked like to the rainbow, and each performing yearly sundry thousands of miles of migration about which scientists wrote wisely but did not understand.

No 'fortuitous concourse of elements' working blindly through any millions of years could quite account for why warblers are so beautiful. No mechanistic theory, even bolstered by mutations, has ever quite answered for the colors of the cerulean warbler, or the vespers of the woodthrush, or the swansong, or—goose music. I dare say this boy's convictions would be harder to shake than those of many inductive theologians.

—Aldo Leopold in A Sand County Almanac