Chaetura swift, Waneka Lake, Boulder County, Apr. 21

[Ted Floyd]

Hello, everybody.

Yesterday evening, Easter Sunday, Apr. 21, I saw a small swift over Waneka Lake, Boulder County, that I thought was good for Vaux swift. I heard it briefly, and it sure didn't sound like a chimney swift. However, I haven't had much experience with listening to Vaux swifts since I lived in western Nevada close to 20 years ago. I got some poor photos, but they might contain some clues regarding wing shape. Also, there is the matter of date, as Apr. 21 would be the earliest documented occurrence of chimney swift in Boulder County.

Other stuff in recent days at Waneka Lake and nearby Greenlee Preserve and Hecla Pond: wood ducks and hooded mergansers, a Mexican duck x mallard hybrid, 2 greater scaup, black-crowned night-heron, white-faced ibis, bushtits at several places (including birds tending a nest), a marsh wren, a long-staying white-throated sparrow, and yellow-rumped warblers on the uptick.

Over at the Jasper Road playa near the Boulder Creek crossing at 109th St., eastern Boulder County, conditions are good for shorebirds. On Sat. morning, Apr. 20, I saw greater and lesser yellowlegses there, plus a long-billed curlew. And a Virginia rail was going off. The site might be worth keeping an eye on for the next several weeks.

Ted Floyd

Lafayette, Boulder County

[Steve Larson]

Hello all

Ted's swift report got me to thinking about early swifts in my personal records. I looked back through my records for Chimney Swift in Boulder County and the earliest one I have is 23 March 1977! My notes indicate the bird was calling but I have no recollection of this sighting. I also have records for 29-30 April 1974 and 26 April 1979. All other dates I have for Colorado are in May or later. It should be noted that several Vaux's Swifts wintered in Florida and Louisiana this past year. The shape of the swift in Ted's photo is very similar to the photos I took of Vaux's Swifts in Louisiana in March this year.

https://ebird.org/view/checklist/S53624713

Steve Larson 

Northglenn, CO

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[David Tønnessen]

In addition to Ted and Andy's reports of possible Vaux's Swifts, I have received two other alerts from eBird of Chaetura swifts in the last two days. The low clouds that smothered much of the front range today are supposed to linger into the early-mid morning tomorrow in at least Denver and south, maybe forcing flight-feeding birds like swallows and swifts to feed close to the ground. Might be worth keeping an eye out around buggy bodies of water for those who are able to!

David Tonnessen

Colorado Springs, CO

[Bryan Guarente]

To throw some fuel onto the "which swift was it?" fire, here is the last four days of 850mb winds, plus tomorrow's winds as well (April 23).  These winds are near the surface here in Colorado, but about 1 - 1.5km above the ground in other closer to sea level locations.  This is every three hours of data and the local mountain time is listed in the bottom right corner of the movie while I click through each time step.  The green circle located in the middle of the image is Longmont, CO, just for reference.  Note the direction that the winds are predominantly from on each day and what that might mean for the Chaetura swift species that might show up, with Vaux's being predominantly West Coastal, and Chimney being predominantly Gulf Coastal.  Just fuel for the fire.

 850mb_winds_April19-24_2019_720p.mov

If you wanted to explore this on your own, you can go to earth.nullschool.net to check it out as well.  Hit the "Earth" button in the bottom left to start navigating the times and the levels.  I chose 850mb for my movie, but you might want to choose others.  

Best of luck hunting for these birds if you go out.  I stopped Monday morning at McIntosh Lake here in Longmont this morning and found over 450 swallows flying low over the lake, but no swifts.  Will keep looking though.

Bryan Guarente

Meteorologist/Instructional Designer

UCAR/The COMET Program

Boulder, CO

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