Monday, July 30, 2012

Flycatchers, Empidonax Complex


Day 300: I spent approximately five hours pacing up and down the same 500' of roadway in the Ohop Valley today, watching for that Yellowthroat or any other Warbler who might pass through my field of view. I did not see the Yellowthroat, and only spotted two Warbler-shaped blurs. What I did find was a mystery plant (something I am certain was accidentally introduced and probably has potential as an invasive) and a delightful, if elusive, selection of Flycatchers.

Roger Tory Peterson says of the Empidonax complex that they are "...so similar as to confound the experts. They are more readily identified by nesting habits, habitat and voice than by subtle color differences. (The) wise field man usually lets most of them go as just Empidonaxes." After careful study of several field guides including RTP, I could not decide between Willow (aka Traill's) which gave the most closely matching call or Pacific Slope. Willow is less common; however the habitat and habits also seemed to suggest it.

One thing I do know for certain: the lower bird was parent to the upper one. I saw the young one being fed. The two flew off into the wild roses together, darting quickly out of sight at the cry of a Bald Eagle from overhead. A silence fell on the thicket until the small birds were certain the danger had passed. Once again the rose bushes came alive with the sound of "Whit! Whit!" but only occasionally would some brave soul venture out to the tip of a branch and into range of my lens.

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