Verification of Unusual
Rec. # 2011-50
|Scientific name:||Chaetura vauxi|
|Date:||9 October 2011|
|Length of time observed:||20 seconds|
|Location:||Provo Airport Dike (Southeast corner).|
|Distance to bird:||60 feet|
|Optical equipment:||8x42 Binoculars|
|Description: Size of bird:||Smaller than Barn Swallows|
|(Description:) Basic Shape:||Short tailed swift|
|(Description:) Overall Pattern:||Brown|
|(Description:) Bill Type:||Small and pointy. tiny|
Field Marks and
Flew past with the flocks of Barn Swallows heading south. We got a good close
look at it but not a long look. The bird was brown all over. Paler brown on the
throat. The bird had a tiny bill and short head. Tail was short. The wings were
long and evenly tapered, with a very short 'arm' compared to the long 'hand'.
Wingbeats were stiff and shallow. Looked very small compared to the Barn
We were doing a Big Sit, where we try to see as many species as possible from one spot. Starting around 10:30 am swallows stared streaming past so I faced my chair to the north and carefully watched each swallow as it came by hoping to add another species to our count. All of the swallows were Barn and Tree (mostly Barn). I spotted the swift early and pointed it out to the other sitters as it flew past. It flew by a little over eye level and only maybe 60 feet away. Because I had been looking carefully at a few hundred swallows before it came past and there were swallows around it as it flew past I believe I got a good feel for the relative size compared to the Barn Swallows and it looked much smaller, about 20% smaller.
|Song or call & method of delivery:||None|
|Behavior:||Flew in a straight line past us from North to South. With many Barn and Tree Swallows.|
|Habitat:||Open fields, moat, large bay on Utah Lake.|
were they eliminated:
Eliminated swallows by shape, wingbeat, color and size.
Eliminated Black Swift and White-throated Swift by color and short unnotched tail.
Eliminated Chimney swift by size, pale throat is more common on Vaux's than Chimney, and the range of the Vaux's makes it the more likely swift in Utah. I think most Chimney Swifts should only be a little smaller than a Barn Swallow but I don't have a lot of experience seeing Chimney Swifts with swallows and have never seen Chimney and Vaux's together for size comparison. I have seen Chimney Swifts back east and they looked larger than this bird we saw. I have seen varying measurements in the books and webpages.
this & similar species:
I have seen what I believe were Vaux's Swifts a few times here in Utah and I
have seen Vaux's in Oregon a few times. I have seen Chimney Swifts 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.
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 App in field.|
|Description from:||Notes made later|
|Observer's address:||850 E 100 N Pleasant Grove, UT|
|Observer's e-mail address:||firstname.lastname@example.org|
|Other observers who independently identified this bird:||
Keeli Marvel, Lyle Bingham, Milton Moody.
|Date prepared:||15 & 19 October 2011|