The smaller Calliope has to dash in and out, to avoid getting roughed-up by the Rufous hummingbird who guards the feeder. One occasionally hears hummingbirds make contact, though I have yet to find one that was injured in combat.
Hummingbirds sitting at the feeder are relatively easy to focus on, although they often keep their wings in motion while feeding, causing a blurring effect. Hummingbirds in flight, however, are always a blur, and very difficult to get in focus. Instead of rejecting the inevitable out-of-focus photos, I decided to work with the blur. Male hummingbirds are all about their gorgets (as they would tell you themselves, if they could). I was fortunate to get the gorget in relatively greater focus than the rest of the bird, and vividly displayed, in the last photo of the series. Fill flash helped.