I spent yesterday morning recording Pine Siskins in Whitnall Park, Hales Corner, WI. They were extremely vocal and I managed to make some good recordings of group singing. Recording an isolated individual singing, so that you could really hear the song components, proved to be tricky, but eventually I did find one off by itself who briefly sang into my microphone.
Two summers ago David Sibley posted an article on his excellent blog about Vocal copying in Pine Siskins. He writes about the under reported phenomenon of Pine Siskin mimicry, and one of the species mentioned as being imitated is Dark-eyed Junco, specifically the “tew-tew-tew” call. Having read the article, I was keeping an eye and ear open for examples of mimicry when I replayed my recordings, and as luck would have it, I did capture an imitation of the Dark-eyed Junco “tew-tew-tew” at the very end of this brief song. There may be other imitations in here as well, so please leave a comment if you think you can detect any.