All three of these warblers sing songs that could be considered at least partly buzzy. By examining the structure of each of their songs we can quickly get to the correct species.
Prairie Warbler’s song is very similar. The Elements are all of a similar length and quality to the first Elements of this song. However, Prairie’s Elements are all basically the same length.
In our target song the last Element is much longer, and has a different pitch contour than the prior 8 Elements.
Also, Prairie’s Elements slowly rise in pitch. The Elements in the target song are all basically the same pitch until the last, longer Element.
So Prairie must be ruled out.
Cerulean Warbler’s song is more complicated than Prairie’s, and so maybe that will match our target song. But looking at the typical Cerulean song we see some important differences.
Our target song has two distinctly different Sections. One has several Elements of similar length. It then has one longer, rising Element in the last Section.
Cerulean’s song is even more complicated. First, the song is organized into three distinctly different Sections.
The Elements in the first are somewhat similar to our target song, but are actually more complex, with distinctly 2-Element Phrases.
The next Section has 4 higher, faster Elements that are repeated at trill speed, so fast we can’t really count the number easily. There are no trills in our target song.
The last Section is higher than the the first two. Note that in our target song the last Section’s Element rises in pitch. However in Cerulean’s song the pitch in the last Section is steady, even though the overall Section is the highest in the song. For these reasons, Cerulean can be ruled out.
So the answer must be Black-throated Blue. Black-throated Blue songs are most often 2 Sections, the first containing a variable number of buzzy Elements that are of similar length and pitch. The second Section is a longer, Buzzy, Element that rises in pitch, just like the structure of our target song.
Here are two examples of Black-throated Blue Warbler songs, each showing the same basic structure.
One quick way to identify this song would be to use The Song Finders found in The Warbler Guide. Since this is a Buzzy song, we can go to that part of the Finder. There we see Prairie Warbler and Black-throated Blue as the main choices. The target song has two clearly different Sections, and matches the Black-throated Blue’s quality and structure.
Cerulean’s song, while sometimes confused for Black-throated Blue, has a different structure and quality, as evident by its place in the song finder. Cerulean’s song is never entirely buzzy, which also separates it from our target song.
Using the Song Finder and the Song and Call Companion playlist, it’s also easy to play any potential song and compare them with an unknown species.