Red flowers in the Sierra Nevada seem to attract Hummingbirds in abundance this season. Trumpet shaped penstemons and other similarly shaped flowers have nectar that the hummingbirds eat, and each patch of blooming flowers seems to have at least 2 of the feisty birds hovering and chasing away all intruders.
Earlier this summer, during May, a visit to the eastern side of the Sierras and a hike up a pretty trail at the 8,000 foot elevation brought a surprise. As I walked beneath a pine tree I heard the whir of wings and looked around, expecting to see red or purple flowers. The whirring was overhead so I glanced up, and saw a little greenish hummingbird disappear in the foliage. There was nothing red up there, and I certainly wasn't wearing anything bright, so I moved back and studied that branch.
There was a tiny hummingbird head visible above a little rounded nest, blending into the tree. If I hadn't heard her arrive, I would not have known she had a nest directly above the trail.
If you click the images, you can just see the nest in the first image, towards the upper part of the large branch that goes up and to the left. In the second image, you can see the mother hummingbird's neck and head.
The area where she chose to nest is in a mixed conifer forest next to sagebrush and rabbit brush, so there is a nice mix of flowering plants to gather nectar from, and lots of tiny insects to eat.