Learn from Your Elders

"A white-crowned sparrow’s song consists of a whistle, a series of notes (it’s called a “note complex”), a buzz and a trill.

"When a young white-crowned sparrow looks to stake out its first territory, which is typically a bush, it hasn’t yet settled on a single song. Its note complexes vary from song to song.

"Older birds who’ve nested in the area for more than one season sing the same song, note for note, over and over." [also from the link in the post below]

By season's end, the young bird sounds much like its elders.