AMO a problem for the Greenland White-fronted goose
THE Greenland White-fronted Goose is a species that is in trouble and the most probable cause of its problems is the AMO.
As its name clears tells us, this goose has a white front to its face: a white forehead, a prominent white blaze surrounding the base of its bill, and it has a link with Greenland, the world’s largest non-continental island.
In summer, White-fronted Geese breed on tundra in the far north close to the Arctic. When winter comes, the birds migrate south to areas free of snow and ice. The population falls into two distinct groups.
One group of birds breeds in northern Russia and summers in mainland Europe. The other group breeds in Greenland and summers in Ireland and south-west Scotland. Since they belong to the latter group, the birds that come here each year to spend the winter with us are known as Greenland White-fronted Geese.
The Greenland White-fronted Goose population is falling and has fallen below 20,000 birds for the first time. In the current issue of I-WeBS News, Alyn Walsh, a researcher with our National Parks and Wildlife Service, reports that the last international census shows that the total number of Greenland White-fronted Geese in the world was 18,854 individuals, the lowest number recorded since the spring of 1985.
Some 8,500 Greenland White-fronted Geese winter on the Wexford Slobs each year making the area hugely important for the species. The Wexford Wildfowl Reserve is one of showpieces of nature reserves in Ireland. It functions as an interpretative centre for these geese and is well worth a visit during the winter when the geese are present.
The Wexford population is stable so the decline in the species’ numbers lies elsewhere. The aforementioned Alyn Walsh and Tony Fox, a researcher in Aarhus University in Demark, believe that of the many potential explanations for the declining numbers one of the more convincing is linked to the AMO, the Atlantic Multidecadal Oscillation.
The AMO is a cycle in sea-surface temperatures in the North Atlantic. Warmer sea temperatures since the early 1990s have resulted in more frontal systems traversing further north resulting in snow in Greenland in April and May when the geese arrive to breed.
A blanket of deep snow covering the ground when the hungry birds arrive from Ireland exhausted after the long migration is not a good start to a successful breeding season. The geese face an uncertain future if things continue as they are.