English and Scientific names: 

Vaux’s Swift, Chaetura vauxi

Number of individuals: 

as many as 24

Locality: LOUISIANA: 

East Baton Rouge Parish

Specific Locality: 

Over the University Lakes by the I-10 Dalyrymple exit.

Date(s) when observed: 

02/14, 02/22, and 2/24/2004

Time(s) of day when observed: 

around noon on first two days, from about 1:30 to 5:30 on third

Reporting observer and address: 

Paul Conover

Lafayette, LA 70506

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

Dave Patton, Donna Dittmann, Steve Cardiff, Deb Clark.

Other observers who independently identified the bird(s):

I don’t know who initially reported the birds. Many other birders reported having seen them.

Light conditions: 

Catch-22. When the light was great, the birds were soaring too high. When the weather was poor, and the lighting less than perfect, they came down low. The best light was on the first day, with mostly cloudy skies but occasional brief spots of filtered sun. The second day was sunny, but the birds were specks way up. On the final day, the skies were overcast and threatening rain, but the poor light was a non-factor when the birds would go below the treeline.

Optical equipment: 

Zeiss 10x40 binoculars; new and in excellent condition, Kowa scope, B&W viewfinder of Sony camcorder.

Distance to bird(s): 

from 20-30 yards to hundreds of yards.

Duration of observation:

Total viewing time was about 5 hours

Habitat: 

Heavily urban. Over a series of wooded lakes bordered by large houses with many possible roosting spots [chimneys].

Behavior of bird: 

From high soaring to dipping to water’s surface. Mostly fluttered around at about the altitude of the I-10 bridge. The birds’ paths took them directly over me dozens of times.

Description: 

Small, noticeably stubby swift with very little tail projection. Wings short. In the same basic size class as Chimney Swift.

The markings on individual birds varied in intensity, but all shared the same general pattern:

Ground color of body sooty gray.

Wings same as body with slightly paler area on underwings.   

Chin and throat palest area on undersides, on some almost whitish, on others pale gray. The paleness of the throat area graded evenly to a slightly darker gray breast and belly. The darkest areas on the undersides, however, were paler than the mantle color. The birds tilted quickly enough to give good comparative looks at upper/undersides.

The palest area on the upperside was the rump/uppertail covert area. I never could get an exact fix on the line of demarcation between pale rump and darker mantle, but the difference was obvious. When the birds were overhead, the rump seemed grayish. When they dropped down against a dark background, the color seemed more of a washed-out brown. The color to me was reminiscent of the pale areas on a Siamese cat, pale with brownish tones. On some birds, the pale area was vivid, flashing whitish even when the birds were far across the lake [I have snippets of video showing this]. On others, the rump color was visibly but not strikingly different from the mantle color.

The birds flapped rapidly in a manic bat-like fashion at times, and flapped-and-glided at others.    

Voice: 

Not heard—traffic made hearing impossible.

Similar species:

Chimney Swift is the most expected similar species, although other  [extralimital] small swifts are possible.

                Chimney Swift: I see this species in big numbers all summer long, and have for over 30 years. I study them pretty well at close and far range in a variety of behaviors. I pay close attention to them knowing that I may have to separate them from Vaux’s Swifts at some point. That said, I haven’t seen one since October, so I’m operating on memory and instinct here.

Chimney Swifts have longer, straighter-sided tails, and longer wings. Their wings generally seem long enough to have a span of even width down part of the wing.

The birds in question, on the other hand, had no great extension of tail beyond the rear edge of the wings. What tail they showed wasn’t straight-sided, but seemed strongly tapered in, much narrower than the rest of the body. The tail feathers themselves often seemed hidden by the coverts. The wings seemed to have a more pronounced taper with no noticeable span of even width.

In terms of overall shape, these birds had a definitely chunky appearance. They didn’t look like “cigars with wings”, they seemed like butterballs. They flapped faster, and seemed to get less glide out of each burst of flapping.

In terms of comparison of Chimney to Vaux’s, what struck me on first glance was an analogy of Calliope Hummingbirds [fat, no tail] to Rufous.

In terms of coloration, Chimney Swifts—even those with paler throats--are not as pale on the throat as many of the BR birds, and certainly not as pale on the rump.

If brownish tinge on the rump signals Vaux’s over more southerly swifts, these birds are Vaux’s.

Photographs or tape recordings obtained? 

I videotaped perhaps as much as an hour of these birds, and made stills from them. I also took digital pictures. The videotape has a few scenes of birds below the horizon, showing pale rumps even from a great distance.

Previous experience: 

Very little. I’ve seen them out west, but never enough to get a good feel for them.

Identification aids at time of observation:

None.

after observation: 

Handbook of Birds of the World volume with swifts, and any other books I could grab. Also all available photos on the Internet. Not a well-represented species.

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

I’m positive that they’re not Chimney Swifts, although I can’t absolutely rule out other possibilities. By odds, though, you wouldn’t think that 2 dozen of a longshot possibility would end up together here.

Reporter: 

Paul Conover

Date and time: 

March 14, 2004