Hammonds/Dusky Flycatcher Comparison
Hammonds on left, Dusky on right
Photos by Susan Riddle
If you are in the field and have narrowed your choice of flycatchers down to a silent Hammonds or Dusky, and none of the behavior, head shape, or outer tail feather color have helped resolve the identification:
One of the ways to tell Hammonds and Dusky flycatchers apart is to look at the relative lengths of the primary (wing) feathers and the retrices (tail feathers). In the field, consider the length of the observed primary and then compare it to the observed length of the tail as it extends beyond the wing tip. If you can imagine the primary as being about twice as long as the tail, you are looking at a Hammonds. Or, the Hammonds tail extension is "Half" the primary, which is easier to remember. If the wing and tail lengths are about the same, you are looking at a Dusky.