At mid day today (9 Jan 2015) there was an adult hybrid Lesser Back-backed x Herring at Quidi Vidi Lake. It dropped down to the watering hole at the Virginia River. There were four other birders there who wondered why I identified it as such and wanted to see some pictures, so here they are. The bird was fairly close but not present long. This is a regular hybrid combination during the winter in St. John's with a couple or three or more adult individuals present but only this one so far this winter.
This bird was dark as a paler LBBG but the heavy Herring Gull like structure and pinkish-yellow legs were the signals that mean hybrid LBBGxHERG.
These two shots above show the Herring Gull like character of the bird.
The wingtip pattern pretty well annihilates any arguments this could be a pure LBBG. LBBG show more extensive black on each of the outer six most primaries and never (?) show the white tipped tongues visible on the upper side of P 7 & P8.
Compare the underside of the wing tip pattern of the LBBGxHERG hybrid (picture above) with the shot below of the domesticated adult LBBG that lives at the west end of Quidi Vidi Lake. The more extensive black running up the primaries especially P7-P9 creates a fuller hand on a LBBG than a Herring Gull and this hybrid gull. The same is true for the upper side of the wing.
adult Lesser Black-backed Gull Quidi Vidi Lake, Dec 2014
Happy Gulling. We are back into that season where gull watching is just about the last place to mine for winter rarities.
P.S. Very disappointed at how the mantle colour of this gull changed from a steely bluish gray in my files to a mud gray after the downloading to this blog. I often notice a significant loss of colour and sharpness when the pictures are displayed on this blog. Guess there is nothing that can be done about this but it is more than a nuisance when shades of gray matter.