This requires some practice in order to develop a discerning ear. Many species have very abrupt or very subtle upslurs or downslurs that are helpful for identification but difficult to hear. Paying attention to pitch changes as you listen to bird songs will quickly increase your ability to detect these changes. Listen to the phrases of this Northern Cardinal song. The notes at the beginning of the song are distinctly upslurred, and the notes after that are sharply downslurred. Try to follow along in the sonagram to get a better sense of the shape of each note. As you listen for these features in other songs your ability to hear them will improve. Northern Cardinal. The sonagram shown above accompanying the Cardinal recording is simply a graph of pitch over time. Time advances from left to right, and sounds with higher pitch appear higher on the graph. The first three notes at the left begin low and end high, while the following notes begin high and end low. To learn more about reading sonagrams check out Nathan Pieplows excellent series beginning at http earbirding. Unlike the sharply slurred notes of the Cardinal, the song of White throated Sparrow is a series of clear whistles with almost no change in pitch. This, and the longer notes slower rhythm, gives it a much more gentle quality than the Cardinal. The song of Golden crowned Sparrow is also a series of simple clear whistles, very similar to White throated, but one or more of those whistles changes pitch, creating a very different song. In these two species, and most others, such patterns of pitch change are consistent and offer some of the most reliable field marks for song identification. In this White throated Sparrow song the first note is slightly higher but after that there is almost no change in pitch. In the Golden crowned Sparrow song the first note is downslurred, not level, and each note after that is lower than the one before, creating an overall descending trend for the pitch of the whole song. White throated Sparrow. Golden crowned Sparrow. The next installment will cover time as an identification clue.