Verification of Unusual
Rec. # 2011-24
|Scientific name:||Chaetura vauxi|
|Date:||11 May 2011|
|Time:||10:00 - 11:00 a.m.|
|Length of time observed:||10 minutes|
|Location:||American Fork Boat Harbor|
|Distance to bird:||40 feet - 100 feet|
|Optical equipment:||8x10 Binoculars|
|Weather:||Overcast and breezy.|
|Light Conditions:||Sometimes good and sometimes bad, depending on where the bird was in the sky and the background.|
|Description: Size of bird:||Small, swallow sized maybe a little smaller. Difficult to judge.|
|(Description:) Basic Shape:||A pickle taped to a boomerang.|
|(Description:) Overall Pattern:||brownish|
|(Description:) Bill Type:||Difficult to see. just a small point on the front of the bird.|
Field Marks and
The bird was brown all over. Much paler brown on the throat and chest. The
paler area blended darker on the lower belly to the dark tail. The bird had a
tiny bill and short head. Tail was short and when folded looked square or
slightly rounded depending on angle (tail never looked notched). The wings were
long and mostly evenly tapered, with a very, very short 'arm' compared to the
long 'hand'. Wingbeats were stiff and shallow. The wings did not fold back
toward the back of the bird at the bottom of the wingbeat as much as a swallow's
wings do. Because of our vantage, surrounded by trees, we were never able to
get good looks at the top or rump of the bird. It was always flying overhead.
Whenever it got some distance away the view was blocked by trees.
|Song or call & method of delivery:||It flew directly over us several times but we never heard it call.|
|Behavior:||Flying about swiftly. We would see it fly over then would loose it behind trees. It was mostly flying just above the treetops. Sometimes it would be gone for several minutes at a time then would come back and circle over us for a while before disappearing again. This happened a few times. It could have been flying out over the lake. The lake shore was flooded up into the trees so we couldn't get a clear view of the open lake in this area without having to wade through water. The swift was very loosely associating with swallows.|
|Habitat:||Flying over a flooded riparian woodland at the very edge of Utah Lake.|
were they eliminated:
Eliminated swallows by shape, wingbeat and color.
Eliminated and by color and short unnotched tail.
Eliminated by pale chest down to belly and the range of the Vaux's makes it the more likely swift in Utah. After returning home I compared Eric's photos side-by-side with Sibley's swift shape drawing (found here - http://www.sibleyguides.com/2010/10/identifying-chimney-and-vauxs-swifts-by-wing-shape/) and feel the photos more closely match the Vaux's Swift body shape.
this & similar species:
I have seen what I believe were Vaux's Swifts a couple
of times here in Utah and I have seen Vaux's in Oregon a few times. I have seen
in TX, MA, VA, NC, OH and ON. I have never seen Vaux's
and Chimney together. I do most of my birding in Utah so don't have a ton of
experience with either species. Hopefully there are members on the records
committee with more experience than me who will be able to identify the photos.
I have lots of experience with White-throated Swifts. Watching them has given me a good feel for the differences between swifts and swallows.
|References consulted:||The Sibley Guide to Birds. And when I got home the Sibley webpage "Identification challenge: Vaux s vs. Chimney Swift" - http://www.sibleyguides.com/bird-info/vauxs-swift/|
|Description from:||Notes made later|
|Observer's e-mail address:||firstname.lastname@example.org|
|Other observers who independently identified this bird:||Eric Peterson was with me and took the photos. KC Childs saw it that same day, about a half hour after Eric and I left.|
|Date prepared:||13 & 14 April 2011|
|Additional_Comments:||Photo were taken by Eric Peterson. There may be more photos if needed. These were the best ones.|