English and Scientific names:

Vaux’s Swift (Chaetura vauxi)

Number of individuals: 


Locality: LOUISIANA: 

East Baton Rouge

Specific Locality:

LSU Aquaculture Research Station, ca. 3 mi. S of LSU Campus, Baton Rouge

Date(s) when observed:

6 March 2008

Time(s) of day when observed:  

5:15-5:30 PM CST

Reporting observer and address:

Justin Bosler  827 C E. Boyd Dr. Baton Rouge, LA

Other observers accompanying reporter who also identified the bird(s):

Devin Bosler

Other observers accompanying reporter who independently identified the bird(s):


Light conditions (position of bird in relation to shade and to direction and amount of light):

Overcast with adequate late afternoon light as the swifts were flying fairly low beneath the low ceiling of dark (rain) clouds.  Backlighting not an issue, in this case.

Optical equipment: 

Zeiss Victory FL 8x42 binocular (good condition)

Distance to bird(s): 

~25 meters at closest point

Duration of observation:

Approximately 15 minutes


Open, residential woodlot adjacent to active aquaculture facility with multiple crawfish and catfish ponds.

Behavior of bird: 

The swifts were first heard, and then seen overhead at ~5:15 PM.  They were actively 

screening insects 20-25 meters up in the company of ~50 Purple Martins and 5-6 Barn Swallows.  Vocalizations were heard on several occasions throughout the observation; probably 5+ series of calls over a 15-minute period.  Low rain clouds associated with a frontal system rolled in from the west maybe 30-45 minutes prior.  All 4 swifts usually stuck close together and flew in loose elliptical patterns for roughly 15 minutes before moving off to the N to an unknown roost site in Baton Rouge.


Small, dark-bodied swifts with short tails and long wings.  The throat was pale grayish-brown and blended into the slightly darker breast.  The remainder of the underparts was dark brown.  Upperparts were uniformly dark brown with rump somewhat lighter brown.  Flight style consisted of very rapid wingbeats and short glides.  While gliding, the leading edges of the wings appeared very straight across, and not as swept back as I would expect in Chimney Swift (CHSW).  Most diagnostic, however, were the vocalizations which are described below.    


A very high-pitched chipping and twittering which seemed to blend together after several seconds and faded away as a raspy (screechy?) trill.

Similar species:

Similar Chaeturine swift is the Chimney Swift.  Readily separated from VASW by louder, sharper, and unblended vocalizations, not nearly as high-pitched and insect-like.  Also, CHSW are slightly larger with longer wings and tail, and average darker overall with less contrasting rump.  Breast usually darker with less contrast between upper breast and belly.  Also, the date of occurrence is a strike against CHSW considering there are no substantiated/accepted records of that species in early March.

Photographs or tape recordings obtained?

Unfortunately, no photos/video obtained.

Previous experience with this species: 

Seen on multiple occasions between CA, OR, and WA.  Most recently in sc. Oregon, in the town of Lakeview, during Summer 2007.  Only two previous encounters with this species in LA (24 Feb 2006 and 19 Jan 2007)

Identification aids:

NG Complete Birds of N.A. (Alderfer, 2006)

This description is written from: 

Notes made during the observation and memory.

Are you positive of your identification? If not, explain: 


Yes, 100% positive.


Justin Bosler   

Date and time: 

11 March 2008    6:00 PM CDT