We spotted these beautiful Mountain Bluebirds this fall, while we were in the Tetons, around Mormon Row…
Most studies of the Mountain Bluebird involve birds in nest boxes. Little is known about natural nest site requirements.
Only the female builds the nest. The male sometimes acts as if he is helping, but he either brings no nest material or he drops it on the way.
Mountain and Western bluebirds compete for nest boxes, and may exclude each other from their territories. In the small area where they overlap, the Mountain Bluebird dominates the Eastern Bluebird. This relationship may limit the westward expansion of the Eastern Bluebird.
The Mountain Bluebird often occurs outside its normal range in winter. Individuals are casually recorded in western and northern Alaska, and in the midwestern and eastern states.