James Nestler asks: What do butter-butts NATURALLY eat?
>
> Yellow-rumps eat suet at feeders (but not at my place). But what are
these
> little guys naturally eating around here ("here" being the Pacific
Northwest
> or Cascadia or whatever Tweeters decided to call it)? I see them
> apparently feeding in Russian Olive trees, but those aren't really
"natural"
> for here either. Anybody know of any studies?

James, I assume your questioning only the winter survival strategy of
Audubon's Warblers. I suspect Yellow-rumped (Audubon's) Warblers only
occasionally wintered east of the Cascades prior to arrival of exotic
plantings. This is because I rarely encounter this species in natural
riparian habitats in winter, especially after the onset of Arctic freezes.
Berries draping the extensive plantings of Russian olive are very
attractive to this species in winter, as are mature apple orchards (for
unpicked fruit either on trees or on the ground). I also often have
observed these warblers poke about the furrowed trunks of mature apples,
presumably they're gleaning for dormant (or, on warm winter days, active)
insects. Crevice gleaning in the deeply furrowed, flaky bark of mature pear
trees also attracts this warbler, possibly on account of the usual dense
overwintering population of pear psylla larvae or adults (the fly that
makes pears sticky).

There is a sparse wintering population of Yellow-rumped (Myrtle) Warblers
east of the Cascades in the southern Columbia Basin in natural riparian
habitats. These seem to be most numerous in dense stands of tall willows,
especially peachleaf willows (Salix amygdaloides). Occasional individuals
are met with in black cottonwood groves in riparian zone habitats,
especially in early winter.

Of course, Myrtle type Yellow-rumps are abundant in winter in the very
narrow belt of wax myrtle (Myrica californica) trees just inland of
stabilized dunes on the outer coast of Washington and Oregon. A related
species of wax-myrtle (Myrica pennsylvanica) on the northern Atlantic coast
similiarly hosts countless thousands of Myrtle Warblers.

Andy Stepniewski
Wapato WA