|
English
and Scientific names: |
Vaux’s Swift (Chaetura vauxi)
|
|
Number
of individuals: |
1 |
|
Locality:
LOUISIANA: |
East Baton Rouge |
|
Specific
Locality: |
Arsenal
Park at Capitol Lake in downtown Baton Rouge |
|
Date(s)
when observed: |
15
March 2008 |
|
Time(s)
of day when observed: |
5:20
PM CDT and 5:40 PM CDT |
|
Reporting
observer and address: |
Justin
Bosler Baton
Rouge, LA |
|
Other observers
accompanying reporter who also identified the bird(s): |
Devin
Bosler |
|
Other observers who
independently identified the bird(s) |
No
other observers |
|
Light conditions
(position of bird in relation to shade and to direction and amount of light): |
Good
light conditions with sun still relatively high in the western sky. |
|
Optical
equipment: |
Zeiss
Victory FL 8x42 (good condition) |
|
Distance
to bird(s): |
~15-20
meters overhead at closest point; just meters above tree height. |
|
Duration
of observation: |
Two
separate observations: first observed at 5:20 PM for ~1 minute from the north
end of Capitol Lake as it coursed over Arsenal Park with ~35 Purple Martins;
last observed at 5:40 PM for another minute directly overhead at Arsenal Park
with several Purple Martins in the vicinity |
|
Habitat:
|
Aerial
strata above wooded, urban park and edge of small lake |
|
Behavior
of bird: |
Screening
aerial insects with Purple Martins over Arsenal Park and south edge of
Capitol Lake. Appeared to be moving
in a loose elliptical pattern, passing over the south and southeast edge of
Capitol Lake and continuing south over Spanish Town, and then following a
similar flight path during the second observation. |
|
Description: |
Small,
dark-bodied swift with short tail and relatively long wings. The throat was pale grayish-brown and
blended into the slightly darker (but still pale) 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 horizontal (to the bend), and not as swept back as I
would expect in Chimney Swift. During
the 5:40 observation, the bulging throat pouch was seen well as the swift
passed directly overhead. |
|
Voice: |
Unfortunately,
the swift did not cooperate; and therefore, voice could not be used to
further solidify the ID. As is often
the case with swifts, they tend to remain silent while solitary and only
begin to vocalize frequently when interacting with others. |
|
Similar species: |
Chimney
Swifts are slightly larger with longer wings and tail, and average darker overall
with less contrasting rump. Breast
usually darker with less contrast between brown upper breast and dark brown belly. Best features for elimination (aside from
voice), however, were the very rapid wingbeats and the extremely short, and
infrequent, glides. |
|
Photographs or tape
recordings obtained? |
No
photographs or video obtained |
|
Previous experience with
this species: |
Seen
on multiple occasions in CA, OR, and WA.
Most recently in sc. Oregon, in the town of Lakeview, during the
summer of 2007. Only three previous
encounters with this species in LA (24 Feb 2006, 19 Jan 2007, and 6 Mar 2008) |
|
Identification
aids: |
NG
Complete Birds of N.A. (Alderfer, 2006) |
|
This
description is written from: |
This
description is written from notes made during the observation and memory. |
|
Are you positive of your
identification? If not, explain: |
Yes,
100% positive, but wish I could of heard the diagnostic vocalizations. |
|
Reporter:
|
Justin
Bosler
|
|
Date
and time: |
17 April 2008 11:40 PM CDT |