>In the tropics, where so many more warblers winter, I don't think I've ever
>seen pure flocks of a single warbler species (Yellow-rumped may be an
>exception, when they invade tropical areas), because most of them do forage
>in mixed-species flocks. Do Townsend's flock together here just because
>there aren't other species with which to flock, as there would be in
>central and southern Mexico, where most of them winter. Are the Northwest
>wintering Townsend's rather different birds than those that winter in
>Mexico?

Interesting question.

>Here I go again with armchair birding instead of the real thing. There's
>no way I'd rather be doing this than watching mixed flocks of warblers
>(Black-throated Green, Townsend's, Hermit, and Golden-cheeked have been
>reported from a single flock) in the southern Mexican highlands.

On my one birding trip to the canyons and pine forests of the mountains
to the east of Mazatlan, I was surprised by the large flocks of warblers,
or rather by the variety of species which could be found in a single
flock. In one short period we saw a dozen or so species
in perhaps three-four large flocks. Townsend's mixed in with things
like red-faced and red warblers, etc. Don't have my book in front of
me to piece out the exact species, but we were fairly amazed.

-Don Baccus-