Flycatchers are masters of flycatching behavior. They will perch and wait for a flying insect to drift by, then fly out and catch it in midair with a snap of the beak, often returning to the same perch to repeat the process. A notorious subgroup known as the Empidonax flycatchers aka empids are small birds that appear very similar. Separating empids like the dusky and Hammond’s flycatchers is especially difficult, but habitat can be one of the most helpful factors.

The dusky prefers lower elevation conifer and aspen forests bordered by open shrubby areas, while the Hammond’s prefers higher elevation dense conifer forests. The dusky is more common in Teller County, especially along the Rampart Range. I have also seen and heard them on the slopes of Pikes Peak and around Manitou Lake. I have never observed Hammond’s in Teller County, but they likely occur in the subalpine forests of Pikes Peak. Hammond’s prefer higher elevation with thick conifer forest and I do hear them fairly often when hiking near treeline in the Colorado mountains.

Flycatchers have large heads, wide flat beaks, short legs and an upright perching posture. Subtle features separate the dusky from the Hammond’s. The dusky has shorter wingtips that make the tail appear longer relative to the body. The lower mandible of their beak has a yellowish base and a black tip, while on the Hammond’s the lower mandible is entirely black. Both species are smaller than a sparrow and have a grayish body that is yellowish below along with pale wing bars and eye rings. The upper body may appear greenish at times and the sexes are similar.

The sounds of the dusky and Hammond’s are similar but can be separated with practice. Both songs are typically a burst of three rough whistles, but the Hammond’s has more of burry quality, like a ripping sound. Short call notes can also alert birders to their presence. While habitat is a vital factor, keep in mind that during migration dusky and Hammond’s can show up in a wider variety of settings, basically any type of woody or shrubby area. These empids are most likely in Teller from May through September.

Joe LaFleur studied wildlife biology and communications at Colorado State University. He is author of the book Mountain Birds of Teller County and creator of “Better Birdwatching,” a DVD series on North American birds. His betterbirdwatching.com website features a Teller County Bird Checklist and Blog. Contact him with questions and feedback at joe@betterbirdwatching.com.