This small insectivorous bird inhabits the coniferous and mixed forests of western North America.

Hammond's flycatchers are part of the genus Empidonax, which includes a dozen of other species.

Despite the relatively large range of the species, Hammond's flycatcher does not present a lot of genetic variations.

This might be the result of a bottleneck event, that could have occurred when the species range was confined to the South of the Pleistocene ice.

Hammond's flycatchers can be found in the Western United States, including Montana, Wyoming, California, Nevada, Utah, Arizona, New Mexico and Colorado.

Overall, their breeding range is formed by regions that have been greatly influenced by past glaciation events.

[5] Male Hammond's flycatchers physically fight at the beginning of the breeding season, locking themselves together in midair and fluttering to the ground.

Females usually lay, in early June, three or four creamy white eggs, sometimes marked with small reddish-brown dots.