To see Black Swift flocks numbering in the hundreds
is indeed exciting. However, this is not an uncommon
event in north central Washington during stormy weather.
The birds are there all along. They normally feed at
altitudes where they go undetected by birders. On clear
days, sharp eyes can sometimes pick them out far above.
Under stormy, low pressure weather conditions, the birds
come down lower to feed and where they are more
readily visible. Having birded in Wenatchee the past
24 years, I find the phenomen exciting and rank the
Black Swift as the most common swift in the area.

I personally suspect the swifts nest right
along the Columbia River in the rocky cliffs, but
have never actually seen them enter a potential
nest site. Furthermore, Black Swifts are known to
feed at great distances from their nest sites.

--Jerry <tangren.family at verizon.net>
Wenatchee WA