Michael,

Really, the difference should be obvious at a glance at 1/2 mile.
Perhaps you've never seen a real Black Swift. They're so big and they
glide... and the moderately forked tail is usually quite apparent.

Gene Hunn.

On Mon, 29 Aug 1994, Michael Smith wrote:

>
> This morning (Sunday) at about 10:00, a large flock of swifts were noted
> in my neighborhood (Madrona, at the intersection of 35th Ave. and Cherry
> St. in Seattle). In about 2 minutes, I counted at least 60 swifts flying
> by, all headed south along the lakeshore. I assumed this to be a
> migratory flock, and diligently looked for Black Swifts among the
> lower-flying birds. I didn't see any, but I was wondering if the Tweets
> have some helpful hints about high-flying swifts? I've seen descriptions
> of their flights and looked for differences, but still can't seem to see
> this. Even at Stevens Pass once, when I knew they were Black Swifts, it
> was difficult to see the differences in flight patterns (maybe because
> they were so low, other things were obvious). I'd like to be able to
> pick apart the swifts at 100 yards...
>
> Mike Smith
> University of Washington
> whimbrel at u.washington.edu
>