Sighting Record for Utah

Common name:	Vaux's Swift
Scientific name:	[Chaetura vauxi]
Date:	5.08.24
Time:	9:30am
Length of time observed:	at least 15 seconds
Number:	1
Age:
Sex:
Location:	south end of Sand Hollow reservoir -- see details below
County:	Washington
Latilong:
Elevation:	~2700 ft
Distance to bird:	25 to 200 ft
Optical equipment:	Swarovski 42x8.5
Weather:	Sunny, clear, VERY windy
Light Conditions:	bright sunshine
Description: Size of bird:	About same as nearby Violet-green Swallows
(Description:) Basic Shape:	swift: stiff sickle-shaped wings, cigar-shaped body
(Description:) Overall Pattern:	low contrast gray-brown, paler at rump
(Description:) Bill Type:	small swift bill
(Description:) Field Marks and Identifying Characteristics:	See "behavior" below for distinguishing flight characteristics. To narrate: I was (obsessively) sorting through a sizable "flock" of foraging migrating swallows, the largest I've seen in the county: mostly violet-greens (40+) but also Bank (30+, most I ve seen away from colony), NRW (20+), Barn (2-3), Cliff (15+), and Tree (2). They were using the cottonwoods and willows as a windbreak and repeatedly coming in at low altitude. The swift came in just above the treetops and made 2-3 wide circles, once flying low enough to see the paler contrast of the rump. I immediately called out SWIFT! Both other birders, Toni Taylor and Natalie Tanner, were able to get on the bird -- Natalie immediately -- and we tracked it nonstop for at least 15 seconds. We all observed the distinctive swift profile (thin, sickle-shaped wings and cigar-shaped body), plain coloration, and distinctive flight pattern (see Behavior, below).
Song or call & method of delivery:	Silent, as were all the swallows, with few exceptions, in the mixed migrating flock
Behavior:	Associating with a large mixed flock of swallows that were utilizing the tall trees near shore as a windbreak to forage over the high-water shallows. Because of the high winds they were abruptly pinwheeling and changing direction and elevation. In contrast, the swift s flight was smoother and more direct with broader, sweeping curves instead of the abrupt changes. Flight appeared more efficient and powerful than swallows, flying with a combo of soaring/gliding with a comparative burst of a few rapid, stiff wingbeats -- once or twice the rapidly "tipsy," almost vibrating wingbeats of Vaux's Swift.
Habitat:	Airborne over the shallows of the reservoir (and no doubt out over the water) inside and above the cottonwoods etc lining the shoreline.
Similar species and how were they eliminated:	Violet-green (and other) Swallow: Similar size but plain, almost uniform gray-brown color and distinct flight pattern. See "behavior" above - White-throated Swift: Not big enough; overall slower flight; uniform-looking plumage. We later observed White-throats and noted their striking contrasty colors, larger size, sleeker overall appearance, more rapid, agile and aggressive flight. - Black Swift: Not big enough; flight less gliding (more wingbeats) - Chimney Swift: Even more unlikely, but the contrasting paler rump was visible on this bird.
Previous experience with this & similar species:	2 Vaux s Swifts reported on April 27. 30+ years in W Washington observing Vaux's Swifts and targeting them specifically to pick them out of mixed swallow flocks. During peak spring migration (which, interestingly, was May 9-13, we sometimes had 100s pass over (this was in the 90s, but numbers have sharply declined); a few continued to nest on my block. A chimney roost was utilized by about 70 swifts every September two blocks from my home.
References consulted:	Sibley's field guide
Description from:	From memory
Observer:	Paul Hicks + 2 others
Observer's address:	1630 E 2450 So #26, St George 84790
Observer's e-mail address:	**
Other observers who independently identified this bird:	I don't think the other two (Natalie Tanner and Toni Taylor) would have noticed or independently IDed the bird if I had not called out the bird and its distinguishing field marks in real time: thin, sickle-shaped wings, plus flight pattern. But they definitely saw the distinguishing characteristics once I pointed them out.
Date prepared:	5.09.24
Additional material:
Additional comments:	20See report for April 26 sighting