I'd like to add my own experiences to the discussion about Swifts. I've
always had a special fondness for that family of birds, especially the
larger species. It stems from my biology undergrad days in the late
70's, when I spent a semester doing field work in Kenya. I spent many
long hours sitting atop a high cliff at the rim of Hell's Gate gorge,
recording observations of a Baboon troop that foraged in the valley
below. During the first few days, I often heard a mysterious roaring
noise that seemed to echo from around the canyon, but I couldn't
pinpoint the source of the sound. At first I thought it must somehow
just be some bizarre product of the wind as it swirled around the
cliffs, but then there were times when the sound seemed to increase in
volume and then abruptly drop in pitch and trail off, sounding like an
invisible jet whizzing by me.

Eventually I identified the source of the noise -- small groups of
Mottled Swifts flying in perfect formation! I got so I could pick them
out with my binoculars from across the canyon, and watch as they rocketed
around the valley without so much as a single perceptable wingbeat. They
would be right in front of me one moment, and an instant later they
would be distant specks against the far cliff. The way they magically
avoided crashing into the rock formations by making last second evasive
maneuvers (in unison) would seem to violate all laws of physics.
Whenever they would head straight at me, it was all I could do to keep
from diving for cover. Often they would pass just inches from my head.
What a thill it all was! Each day I looked forward to returning to my
perch on the cliff. I never tired of watching them.

It's hard for me to believe that they were only going as fast as the
reference Joe Morlan quoted claimed they do. They seemed to go at
incredible speeds. If it's true, then it was quite an illusion. It
seems that one might be able to measure their speed simply be recording
the sound as they fly by, and measuring the Doppler shift?

To add a little local flavor for our regional lists, I might add that
Mottled Swifts are only a little larger than our northwest versions --
i.e. White-throated and Black Swifts. Ours are plenty entertaining to
watch in their own right. I know of a few good spots in Oregon to watch
them in action:

White-throated Swifts: The best spot I know is at the top of the hill
across from the main parking lot at Smith Rock State Park (just E of Hwy
97 between Madras and Redmond, Deschutes Co). From the observation area
below the parking lot, take the gravel trail down to the river and cross
the bridge. Turn right and follow the trail up to the top of the hill.
It looks like a harder walk than it is. Every time I've been up there in
June and July, I've had dozens of White-throated Swifts whizzing by at
eye level.

Alternatively, the Crooked River Gorge wayside a few miles to the north
(along hwy 87, Jefferson Co, right at the Deschutes Co line) usually
yields a few good looks at White-throated Swifts. There aren't as many
as at Smith Rock, and they seem to spend most of their time way down
below or high above, but it's an easy place to check when passing by.

Black Swifts: The only known nesting place in Oregon is at Salt Creek
Falls (on the south side of Hwy 58, just west of the pass over the
Cascades, Lane Co). One can see them from the overlook, but I've
been able to get much closer by crossing the creek above the falls,
and following the trail that follows the bluff on the other side for
about a mile to a bald ridgetop. I've had them zoom by just a few feet
from me there. Cloudy days seem to be better for some reason. Right
about now should be the time of year to see them.

Skip

--
Skip_Russell at intersolv.com
Aloha, Oregon