ML474454821

Age

Not specified

Sex

Not specified

Observation details

Continuing. Found by Jodi Boe. The task is to eliminate LTJA as the other possibility. Field marks visible in the photos include an apparent Sibley field mark of a pale crescent at base of forehead (pointed out to me by S Aubol) not present in LTJA, the border of the dark cap being less neat than in LTJA, unbarred axillaries which are usually not barred in adult PAJA, more extensive white flash on the base of the dorsal side of primaries than in LTJA. Pale shafts (not to be confused with white primary webs that create the "white flash") on the dorsal side of the primaries usually fewer than 3 in LTJA. This bird shows more than 5. This bird lay prone on the ground while it watched RBGUs feeding in a recently disked field. It regularly flew after gulls, forcing one to surrender its meal, which the jaeger would catch in mid-air and consume. This routine was done three times during the hour that we watched the bird.

Technical information

Model

Canon EOS R5

Lens

RF800mm F11 IS STM + EXTENDER RF1.4x

ISO

2000

Focal length

1120 mm

Flash

Flash did not fire

f-stop

f/16.0

Shutter speed

1/800 sec

Dimensions

2984 pixels x 1989 pixels

Original file size

1.49 MB