Hi all, Two excellent birders have written that a Costa's can sing an Anna's song. We weren't aware of this yesterday, and the sources we have consulted indicate otherwise. We would love more information! This is why we came to our conclusion: The Costa's type hummingbird opens its mouth and sings a song which matches Anna's Hummer almost exactly for me. Anna's Hummingbird is one of my 10 or 20 most familiar birds. I have seen 4 Costa's ever.
With that being said, while declaring the bird as a hybrid was perhaps an overly quick call, we have yet to find a source online that records Costa's singing an exact Anna's song. Does anyone know of a source, online or in the literature that records this phenomenon?
The reason we made this call was because none of the apps or websites we checked for recordings had any documentation of Costa's singing an Anna's song. Courtney also has Hummingbirds of North America by Steve Howell, highly recommended to her, which states that hybrids will look more like Costa's and sing an Anna's song or intermediate.
So let's help each other in figuring this out if we can: What sources do we have with info on Costa's singing Anna's songs, and what field observations are there of this? We don't have a BNA subscription, but a preview from Google says young males Costa's can sing a similar song to Anna's but 'fainter and less sustained'. This bird sang at full volume several 12-second songs in perfect Anna's tone. You can hear this on our recordings. Our recordings of the bird's chase calls also sound similar to Anna's.
We would of course love if this turns out to be a pure Costa's Hummingbird! We just are trying to represent the truth of the situation in the best way we can. Let us know what you think?
Also, if anyone knows hummingbird experts and would like to send the photos along (Nolan took some great ones yesterday), that could be helpful too.