Song Sparrow

Here is one of natures great singers, an aptly named Song Sparrow. Here is a little of what Wikipedia has to say about their song:

The songs are very crisp, clear, and precise, making them easily distinguishable by human ears. A particular song is determined not only by pitch and rhythm but also by the timbre of the trills. Although one bird will know many songs—as many as 20 different tunes with as many as 1000 improvised variations on the basic theme, unlike thrushes, the song sparrow usually repeats the same song many times before switching to a different song.

This photo was taken in April 2010 in the Swan Lake Nature Sanctuary.