UPDATE 9/8/10: It seems certain that this bird is indeed a COSTA'S x LUCIFER HUMMINGBIRD hybrid, apparently the first of its kind recorded.
ORIGINAL POST: Ash Canyon, in the Huachuca Mtns of southeast Arizona, has been a hotbed of hybrid hummers this year. Reported hybrid combos have been "Lucifer x Anna's" and "Costa's x Anna's". On my first late summer trip to the southwest, I was pleased to run into an interesting apparent hybrid.
While watching the feeders at Mary Jo's in Ash Canyon on 3 Aug 2010, I heard a singing Costa's Hummingbird. Upon tracking the bird down, I was surprised to see a bird that resembled a Costa's but had a noticeably long tail. It sang repeatedly while I was observing it, always producing a typical Costa's song.
Since it was singing a typical Costa's song the bird is obviously part Costa's...but its long tail, projecting well beyond the UTCs, tells us that this is no pure bird. Due to the poor quality of the photos, it is difficult to discern exact plumage details. Lucifer Hummingbird breeds nearby, and it makes one wonder if that is the other parent. The long tail with a fork supports that. The bill is a bit longish and slightly decurved, but this may be within range of Costa's(?). The gorget seems a bit less elongated than a typical Costa's should show.
Any comments on this bird? According to Howell (2002), a Costa's x Lucifer hybrid had not been recorded as of that writing.
Another interesting question might be...if not aware of the bird's vocalizations, what would you call it?