English and Scientific names:

Vaux’s Swift (Chaetura vauxi vauxi?)

Number of individuals: 

8

Locality: LOUISIANA: 

E. Baton Rouge Parish

Specific Locality:

over City Park Lake on Morning Glory Ave./May St., Baton Rouge

Date(s) when observed:

24 January 2008

Time(s) of day when observed:  

~4:15 PM CST

Reporting observer and address:

Devin Bosler

Baton Rouge, LA

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

Van Remsen, David Anderson

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

none

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

Overcast w/ low ceiling and adequate afternoon light.

Optical equipment: 

Zeiss Victory FL 8x42 (excellent condition)

Distance to bird(s): 

ca. 50 meters up at closest point

Duration of observation:

~10 min.

Habitat: 

Suburban shallow, freshwater lakes surrounded by residential/disturbed deciduous woodlots (primarily live oaks).

Behavior of bird: 

The swifts were screening insects in a compact group over the lake in association w/ Purple Martins and Tree Swallows.  Rapid wing beats followed by brief glides was noted as they flew in and out of view.

 

Description:

The group of Vaux’s Swifts (VASW) were screening aerial insects over the lake w/ Purple Martins (PUMA) and Tree Swallows (TRSW).  First, a single Chaetura swift came into view followed by 5 more (the other 2 were spotted later).  A relatively small swift w/ a noticeably pale gray-brown throat and breast contrasting w/ the belly and upperparts.  Tails were very short and inconspicuous in flight.  The flight style was diagnostic w/ very rapid, shallow wing beats followed by a short period of gliding.  The vocalizations were the ID clincher.  Calls were a series a high-pitched chip notes and twittering which blended together into an ‘insect-like’ trill. 

 

Voice:

A rapid series of high-pitched twittering and chipping notes.  Heard faintly over traffic noise.

Similar species:

Most reliably, Chimney Swift (CHSW) can be eliminated by voice.  CHSW has a lower-pitched chipping and twittering.  CHSW exhibits a slightly different flight style (less rapid wing beats and longer glides on relatively long wings) and has a longer, more conspicuous tail in flight.  Also CHSW is more uniform dark below, lacking a noticeably pale throat and breast.  CHSW can be further eliminated by the date of observation.  There are no previous accepted records of CHSW from January.

Photographs or tape recordings obtained?

Unfortunately, no.

Previous experience with this species: 

Familiar with VASW from CA and several previous encounters in Baton Rouge, LA.

Identification aids:

at time of observation: 

after observation:    National Geographic Complete Birds of N.A. (Alderfer et al. 2005) and Sibley's Guide to Birds (Sibley 2003).none

 

This description is written from: 

 __Yes___ notes made during the observation

 __Yes___notes made after the observation

__Yes___memory.

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

 

Yes, very confident.

Reporter: 

Devin Bosler 

Date and time: 

31 January 2008 

3:00 PM CST