Glaucous Gulls - Gordon Yates

Two lovely shots of a Glaucous Gull feeding on the carcass of a Barnacle Goose.

More photos from Mark and Sally

 Thanks again to Mark and Sally Johnston for this selection of their recent holiday snaps from Islay.

Barnacle Goose

Paps of Jura from Bunnahabhain

Purple Sandpiper

Rock Pipit

Roe Deer

Slavonian Grebe - Loch Indaal

Pale Barnacle Goose

This bird was feeding in a field just south of Bowmore yesterday - the poles and red-and-white tape are meant to scare the geese off the field and stop them feeding there!The goose lacks a lot, but not all, of its black pigment, melanin, and is therefore called 'leucistic' as opposed to 'albino' in which there would be no black at all, even on the bill and legs. Barnacle Geese lacking some black pigment have turned up before on Islay, but I've never seen one which was as white as this one. Such plumage variations are usually carried on a recessive gene and it requires both parents to carry it in order that one or more of the young also show the variation. Obviously in a population of 60,000-70,000, the chances of a male and a female, each with the same gene, pairing and breeding are quite small, hence its rarity. The fact that such a conspicuous bird has not been seen earlier this winter suggests it is a fairly recent arrival, perhaps having come from Ireland as we know that some geese do move here before the proper migration to Iceland next month.
The photograph is as good as I could manage on a cloudy day and at some distance. Someone may get a better one if it stays around.
Malcolm

Canada goose (Branta canadensis sp.) feeding with Barnacle geese at Gruinart

The Cackling Goose was originally considered to be the same species or a subspecies of the Canada Goose, but in July 2004 the American Ornithologists' Union's Committee on Classification and Nomenclature split the two into two species, making Cackling Goose into a full species with the scientific name Branta hutchinsii. The British Ornithologists' Union followed suit in June 2005.

The AOU has divided the many subspecies between the two animals. To the present species were assigned:

Atlantic Canada Goose, Branta canadensis canadensis

Interior Canada Goose, Branta canadensis interior
Giant Canada Goose, Branta canadensis maxima

Moffitt's Canada Goose, Branta canadensis moffitti

Vancouver Canada Goose, Branta canadensis fulva

Dusky Canada Goose, Branta canadensis occidentalis

part of "Lesser complex", Branta canadensis parvipes

The distinctions between the two geese have led to confusion and debate among ornithologists. This has been aggravated by the overlap between the small types of Canada Goose and larger types of Cackling Goose. The old "Lesser Canada Goose" was believed to be a partly hybrid population, with the birds named taverneri considered a mixture of minima, occidentalis and parvipes. In addition, it has been determined that the Barnacle Goose is a derivative of the Cackling Goose lineage, whereas the Hawaiian Goose is an insular representative of the Canada.

(Wikipedia)