A co-worker of mine and I were recently having a conversation about using context clues, and habitat, to help ID a bird by song. If you can narrow a song down to a few species based on the habitat you're in, the ID won't be so difficult. Easy concept, right?
This morning I was walking along, in a Pinon/Juniper hillside in western Colorado, when I heard a Vireo song. I was able to narrow it down to Plumbeous/Gray, and I decided that the notes were too fast and clear to be a Plumbeous; a Gray Vireo. No biggie, it was about the 10th Gray Vireo I had heard.
I looked up ahead of me and saw the bird singing, and it appeared very large for a Gray Vireo. I trained my binoculars on the bird, and I had a first year Cassin's Finch. At first I didn't think that the bird I was looking at was the bird singing. I kept my eye on the finch, and everytime the "Gray Vireo" would sing, the Cassin's Finch had it's bill open, pointed skyward, full of song.
I don't know much about Cassin's Finch as they're learning how to sing. Maybe they often sound like Gray Vireo, and I've just never noticed it because I've never heard that type of song come from a Cassin's in a Pinon/Juniper Habitat. Or, maybe Cassin's Finches, like some other finches, practice mimicry sometimes; if so, there were plenty of Gray Vireos they could pick up the song from.
Has anyone else heard a similar song from a Cassin's Finch, or has anyone ever heard them mimic another species?
Good day today. I also had a Northern Saw-Whet Owl calling on a point!
Love and cherish birds and all things.
Labels: fieldwork, identification, songs