ML66116221

Age

Not specified

Sex

Not specified

Observation details

**very rare; continuing bird found by Tom Burke and Gail Benson. My long-sought first for RMSP! Within F2 loafing flock, it spent most of its time preening, then flew south over the dune and eluded our efforts to re-find it. Small-medium gull overall resembling LAGU but smaller, with much smaller bill and much shorter wingtips (partly an effect of ongoing molt; see below). Legs and bill mostly black, with dusky red tones visible along culmen and especially at bill tip. Basic-aspect head pattern, with large and bold white crescents above and below eyes. White tips of primaries 7 and 8 much larger and fresher than in any LAGU at this date; the next primary (probably p9) about half grown (see photo), implying that p10 has been recently dropped. The fact that this bird had nearly completed its pre-basic molt by mid Aug suggests that it was probably not a full adult, but no specific signs of immature plumage were visible to me, having already been replaced. My views of the white subterminal areas of the primaries were very poor (but nevertheless obviously distinct from LAGU), because they were compromised by a poor angle and by the absence of pp9-10 from the visible flight surface. *Second impression of primary molt: closer inspection of photos seems to show three well-grown primaries extending beyond the tertials on the far (right) wing; this would imply that the half-grown feather is probably p10 (not p9, as first thought). If so, it is possible that the size of the white tip to this feather (relatively small) might allow ageing of the bird as an immature.

Technical information

Model

Canon PowerShot S90

ISO

80

Focal length

6 mm

Flash

Flash did not fire, auto

f-stop

f/4.0

Shutter speed

1/250 sec

Dimensions

2136 pixels x 1282 pixels

Original file size

458.57 KB