In our little neck of the woods in Shenandoah County, our adult male
is always the first to leave the area, usually by many weeks. The
female and young of the year remain. We occasionally get an adult
male later, but he usually stays only briefly, so I suspect, as others
have noted, that these later males are most likely migrating through.
It's also possible that they too are local birds that are simply
roaming around into other territory as they play no role in nesting
and chick-rearing.
This past weekend we had a bit of migrant activity with the appearance
of a redstart (or yellowstart, per the previous message); some very
high, unidirectional Tree Swallows (our breeders disappeared well back
in July); an unidentified (and for me, unidentifiable) empid; and a
Worm-eating Warbler. The latter provided an interesting episode of
avian behavior when he attacked 2 juvenile bluebirds just after they
landed on the power line over our meadow. The warbler zoomed up out
of vegetation below and drove off the larger, but presumably surprised
bluebirds. He dropped back into the shrubbery below, but attacked a
second time when the bluebirds landed on the line again a short
distance away. That time he sat on the line for a minute or so before
dropping back down. For me, this is novel behavior, notable both for
its seemingly unprovoked aggressiveness and for the warbler's
willingness to be active out in the open, which is contrary to the
species' typical behavior. Perhaps he mistook the plump, spotted
thrushes for kestrels and elected to mob them. Maybe he just had a
screw loose. Who knows.
I should note that both redstarts and worm-eaters are local breeders,
but higher up in the national forest. They only appear in our creek-
bottom property during migration, especially fall, suggesting that
post-breeding they may move to the valley bottoms where food and water
are more plentiful as they prepare for migration.
Good birding!
Dave Davis
Arlington and Cedar Creek
