>From Russell Rogers, rrogers at halcyon.com

Michael,

>From my experience with Black Swifts, they seem to fly in a much more
lethargic manner that Vaux's Swifts. They seem to fly at a slower speed
and with slower wing beats. They also have much more of a crescent shape
to there wings, with the wing tips back behind the base of the wings. In
Vaux's Swift, the wings don't seem to dip as far back (this is not shown
in any of the field guides as far as I know). Black Swifts also
seem to hold the wing tips down below horizontal more so that others
swifts. When Black Swifts are gliding, you can see them make tiny
adjustments in there wings. I compare this with the way someone moves
their arms when that are trying to balance themselves on a beam. I never
notice this movement in other swifts. The body shape is different too.
Vaux's Swifts have a shortened cigar shape while Black Swifts are more
elongated. The other field mark to look for of course is the forked tail.

Just last week, on the 22nd I think, I saw about 35 Black Swifts flying
over Madison Park down near the water at around 7:30 or so.

I hope that helps,

Russell

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
>