Continuing our look at the geese species which can be found on Islay this week the spot light is on a rare vagrant Cackling Goose which can occasionally been seen amongst the flocks of wintering Barnacle and Whitefront geese in the Loch Gruinart area. This fairly new species was split from the 'Greater' Canada Goose (Branta canadensis) and is quite challenging to identify.
Islay also has a few resident feral Canada Geese which are much larger in size than the Cackling Goose vagrants. Canada Geese (Branta canadensis) have a large range, breeding across the tundra in much of Canada, Alaska and parts of the northern USA, and wintering in southern North America. Introduced populations are now resident in much of the USA south of the normal breeding range, as well as in Western Europe including the UK. In recent years their population in the UK has increased, making them pests in some inhabited areas.
The Canada Goose is a brown-backed, light-breasted goose with a black head and neck and white cheeks. Its subspecies vary in size, from the 2-kg Cackling goose to the 6.5-kg giant Canada goose, which has a wingspread of up to 2 m. Their almost incessant honking draws attention to their V-formations during migration. Canada geese feed on aquatic plants, grasses, roots, tubers, shoots, leaves, and graze cereals and clover. Continue reading......â€œThe larger bodied Canada Goose species has been divided into a large-bodied, North American interior and southern-breeding species, and a small-bodied tundra-breeding subspecies. The large-bodied group is still known as Canada Goose (Branta canadensis) while the small-bodied group takes the name Cackling Goose (Branta hutchinsii). This means that the English name Cackling Goose, which has in the past been more or less restricted to the smallest subspecies (the far western B. c. minima) is now the species name for all four of the small subspecies. This new species takes the scientific name of the earliest-named subspecies and becomes Branta hutchinsiiâ€ Sibley 2004. The identification of individual species can be difficult. The Ocean Wanderers website provides more discussion and interesting links on this subject.
The attached photographs were taken by myself at Loch Gruinart RSPB reserve on 17 October 2008. It would be interesting to hear from anyone who could positively identify which type of goose this is. From my research of bird guides the most similar type is the Aleutian Cackling Goose. Please contact me or Ron if you can identify this goose. We look forward to hearing from you.
Teresa Morris, Islay Wildscapes.