Verification of Unusual Sight Record
For Utah

Rec. # 2007-06

Common name:

Vaux's Swift

Scientific name: Chaeturi vauxi
Date: May 4, 2007
Time: 1:30-2:30 pm, 5-6 pm
Length of time observed: 2 hours total
Number: 2
Age: Adults (based on date)
Sex: Unknown
Location: North of Willard Bay State Park
County: Box Elder
Latilong:  3 (coords: N 4125.460 W11203.531 )
Elevation: 4286 ft
Distance to bird: 15-100 ft
Optical equipment: 8 x 42 binoculars
Weather: Blustery with cold, spitting spring rain; temps 40s-50s
Light Conditions: Overcast; sun broke through occasionally from west
Description:        Size of bird: Small; wings narrower and body shorter than all swallows present
(Description:)       Basic Shape: Bulging cylindrical body tapering at head and tail; scimitars for wings
(Description:)  Overall Pattern: Blackish-brown upperparts except for pale brown rump and tail; pale dusky-whitish underbody
(Description:)            Bill Type: Tiny; too small to distinguish from head in flight
Field Marks and
Identifying Characteristics:
Very narrow wings at base, appeared long relative to body length, thin and pointed. Body appeared stubby due to short tail and blunt head.

Head: Crown/eye area appeared darker (dusky blackish-brown) and contrasted with dusky-whitish cheek/throat/upper breast.

Wings and body: Dorsal surface of wings and upper back blackish-brown. Rump and dorsal surface of tail pale brown, which contrasted with darker wings and back. Did not see ventral surface of wings or tail well; did not see bare parts at all.
(see photos)
Song or call & method of delivery: None heard
Behavior: Extremely fast and erratic flyer; faster than all swallows present. Fluttery wing beat. Remained over field, rarely sallied out over pond with swallows. Frequently flew within 1 foot of ground. Zoomed around sharply like a rollercoaster car shooting through many twisting and heavily banked turns. Sometimes viewers could not narrate locations of birds fast enough (for others to find birds) to match birds movements. When swifts glided in banked turns, frequently held wings below horizontal by 30-45.
Habitat: Airspace over soggy field with low green grass and forbs. Extensive rangeland, marsh and open water nearby.
Similar species and how
were they eliminated:
All swallows, martin and swifts except for Chimney: Review bird showed no strong white on throat, underparts, or sides of rump, eliminating most swallows, White-throated Swift, and
young/female Purple Martins. Wings extremely narrow from base to tip, unlike all swallows and PUMAs. Stubby tail and dusky brown colors eliminated Barn Swallow and Black Swift. Fast, erratic flight typical only of swifts, especially Vaux s.

Chimney Swift: Review bird s flight pattern and speed much more erratic and faster than CHSW. Review bird s pale brown rump and dorsal surface of tail contrasted strongly with blackish wings and upper back; CHSW s rump and tail likely to be darker, lessening contrast with back/wings.
Review bird was whitish-dusky on portions of face, throat, upper breast; CHSW likely to be darker, perhaps grayish.
Previous experience with
this & similar species:
Vaux s and Black Swift: none Chimney Swift and all swallows: Extensive White-throated Swift: Annual sightings since 2003.
References consulted: Sibley, Cornell s BNA Online Vaux s Swift species account, UOS sight record 2006-42
Description from: Notes made later
Observer: Kristin M. Purdy
Observer's address: 1961 Arapaho Circle, Ogden, UT 84403
Observer's e-mail address:
Other observers who independently identified this bird: Glenn Barlow, Tim Avery, Cindy and Steve Sommerfeld
Date prepared: May 5, 2007
Additional material: Three photos by Tim Avery  [additional photos can be found at the following internet address:]
Additional comments: