Nonconformists

Day 60: Sometimes they does and sometimes they doesn't. I have been puzzling over my "Anna's" hummingbirds for some time now (note well the quotation marks) because they haven't all conformed to type. An Anna's female should look like the one in the main photo here, with a small white dot behind the eye, but in Costa's, it becomes a "postocular stripe" which extends further down the side of the neck. I've had birds which presented in both manners, but more notably, some male birds have displayed red gorget feathers projecting well beyond the back of the neck (the inset shows a bird with a short to medium-length gorget). That distinctive characteristic which made me wonder if they were Costa's. Some exhibited a blurry postocular stripe, and one notable gentleman's head and throat were amethyst purple. Others seemed to fall halfway between the described morphology of either species. When I finally got around to it, a little research took me to a paper published in 1977 by Shirley Wells et al. detailing the discovery of a hybrid between the two in California. Further digging provided the current known range of the hybrids and confirmed that they have been documented on numerous occasions in southwest Washington. Of course, there is a lot of room for variation when you're talking about hybrids based in the genetics of the parent birds and dominant/recessive traits, which explains the crazy, mixed-up morphology dancing around my feeders.