I could use some help identifying this warbler I saw. The sun was behind it, and lots of thick brush, so I apologize I couldn't get a better picture....I know that would help. There were lots of bird songs I was unfamiliar with, but there was one that was a series of quick whistles that kept climbing in pitch. I'm pretty sure this is the bird that sound came from. Looking at my guidebook, and listening to audio of warblers, my guess is a female Prairie Warbler. Pine Warbler, female Cape May Warbler, or juevenille Magnolia Warbler look like options to me as well, but to the best of my memory the songs don't match. I appreciate any and all help. Thanks in advance.