>This weekend I hung an improved (bigger && better) feeder and instantly
>Anna's (mostly female) hummers began utilizing this pseudo-necter source.
> Often two or three would be at the feeder at once. However, every once in a
>while a rufuous hummer would arrive and chase the Anna's off. Often the
>rufous would not even use the feeder. I was wondering if it is common for
>rufous hummingbirds to be more aggressive upon arrival in the Pacific
>Northwest (analgous to late-arriving yellow-headed blackbirds chasing
>red-winged blackbirds off their territories in eastern Wa) ??
>
>Eric Henriksen
>Gig Harbor (Cromwell)
>206 265 2991
>
>Compliance Services International
>206 272 0863
>ericboyd at aol.com

The reason yellowheads chase redwings is because they're larger; might
makes right in the avian world. Rufous is smaller than Anna's, so your
observations are interesting, as in most hummingbird systems larger species
are dominant to smaller. Maybe male Rufous is dominant to female Anna's?
Do male Rufous chase male Anna's? Female Rufous female Anna's? Maybe the
Rufous is territorial there, and the Anna's are "floaters."

I didn't realize Anna's were so common at Gig Harbor. 3 Anna's at a feeder
at once is rather unusual for this area, I thought.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416