Empid ID help, please (Boulder County)

[Richard Trinkner]

Hi folks,

I saw the bird below in the Boulder Community Gardens yesterday afternoon.  At first I thought it was a Dusky Flycatcher (the most common in the Gardens), but it was flicking its tail like a Gray Flycatcher and it looks grayer than a typical Dusky. It was also perched low to the ground, but then in the Gardens there aren't many higher perches. I've stared at the Sibley illustrations of both species for a while now, and can't seem to attain enlightenment. 

I'd appreciate any ID suggestions!

Richard Trinkner

Boulder

[David Tønnessen]

Hey Richard,

Indeed, this is a Dusky as you initially thought. The dark mandible and messy eye-ring are both pointers for Dusky over Gray, which should have almost entirely orange lower mandibles at all ages, and almost no apparent eye-ring. The way Duskies move their tails can make them easily confused with Gray, since neither of these species typically accompany their tail movement with wing movement, as Hammond's and Least to. However, if you'd paid very careful attention to its tail movement, you likely would've noticed a slight upwards movement before dipping down. In the case of Grays, there is typically null upward movement before dipping. 

Hope this helps :)

David Tonnessen

Boulder, CO

--
You received this message because you are subscribed to the Google Groups "Colorado Birds" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/CAG_%3D4zd9P8p-5tkBGEd-T4fVrQq3MnM5Q3WtkGg-QvEp9eAstw%40mail.gmail.com.

[Richard Trinkner]

Thank you all!  The unanimous decision was that this is a Dusky Flycatcher.

Richard

[Caleb A]

Hi Richard!

Thanks for sharing this photo. I wanted to bring something new to this empid discussion: when differentiating between Dusky and Gray, note that Dusky Flycatcher will have a small, dark bill, but Gray Flycatcher has a much larger bill with an orange lower mandible. These two birds are remarkably similar in most other areas, and another mark that can be noted (but not used solely for differentiation due to typical variation) is that Dusky Flycatchers tend to have a rounded crown, whereas Gray Flycatchers tend to have a more flat-head appearance, which subtly alters each bird's GISS.

The birds are happy, and so am I

~Caleb Alons, Larimer County