ML525810651

Age and sex

Adult, Unknown sex - 1

Media notes

Smaller size than the larger Herring Gulls.

Observation details

FRS, submitted 01.19.23 Adult bird with dark mantle and pink legs seen first on the west slope @ 1356 hrs. A probable female bird as the bill was not that large nor was the overall physical size. Bird was not larger than the larger adjacent Herring Gulls. Rounded head shape, like an ICGU, which are their closest genetic relatives. The bill was also ICGU-like in that it was overall greenish-yellow and with a brighter yellow spot at the curve of the upper bill, above the red gonys below. The gonys had a small dark spot at the rear of the gonys, a distal dark spot that Howell & Dunn note they lose as breeding season approaches. The legs also get pinker as breeding season approaches, after March/April. Bird had a large P10 mirror with just a thin subterminal band separating the mirror from the P10 apical. Grant notes that SBGU can have an all-white tip to the P10, like a GBBG. Bird also had relatively dark iris, similar to an ICGU, which could reflect a more northerly breeding. The bird displayed the down-turned gape that SBGU are said to show, similar to a CAGU. Bird was seen downslope on the west slope for about a minute or so before it walked out of side beyond the curve of the west slope. As i had planned to do I slowly walked towards the gulls at the top of the west slope, peeling them off bit by bit, until the SBGU was seen again. All the gulls took flight @ 1430 hrs. They did not return to the west slope for the remainder of the observation, but went over to the east cell closer to the active landfilling location. The SBGU was later seen on the sand of the east cell. The last time I found at least one SBGU a glaucoides ICGU was also present.

Technical information

Model

COOLPIX P600

ISO

200

Focal length

236.5 mm

Flash

Flash did not fire

f-stop

f/6.3

Shutter speed

1/125 sec

Dimensions

4555 pixels x 2510 pixels

Original file size

2.52 MB