ML581821131

Age

Not specified

Sex

Not specified

Behaviors

Flying; Molting

Observation details

One bird I was unsure of in the field but became more convinced of after viewing my photos. Structurally smaller, stockier, and shorter tailed than surrounding Streptoprocne (including rutila), being much closer to a Chaetura in structure. However, it has the large-headed look typical of a Cypseloides, and a clearly squared tail. Shorter-tailed, too, than a Cypseloides niger, and with shorter wings. Interestingly, this bird was in active wing molt, with most secondaries growing in, which agrees on molt timing with some other photos on Macaulay of storeri in molt around this time of year, but I'm unable to find any photos of C. niger in wing molt in Mexico (or in the USA). The first photo does show a faint pale area behind the eye, but it lacks the large white front, so it doesn't appear to be an adult male. Perhaps a female? I would imagine a juvenile would have some white scaling on the belly, which this bird doesn't seem to show.

Technical information

Model

Canon EOS REBEL T5i

Lens

EF300mm f/4L IS USM

ISO

100

Focal length

300 mm

Flash

Flash did not fire

f-stop

f/5.0

Shutter speed

1/1000 sec

Dimensions

787 pixels x 525 pixels

Original file size

30.98 KB