Mountain Bluebird (Sialia currucoides) I generally don’t post successive photos of a particular species. But, in this case I couldn’t help myself. I was torn between the photo posted yesterday and this one — just could not decide which to go with. As a consequence, you get both. I like the translucence of wing feather from back lighting when it can be achieved. This one also has the addition of some nice rim light that shows quite nicely against the dark amber of the montane field background. Mountain Bluebirds use monocular vision to locate insects on the ground when they are fairly close, they turn their head and look at the ground with one eye. When their desired prey is farther away, they use both eyes, or binocular vision. You can see that this particular bird, which had just left its perch, appears to still be looking primarily with one eye as it flies. This produces a rather pleasing tilt of the head and bank of the body just prior to it diving to the ground.