The return of geese to Islay
As the leaves begin to fade and fall and our summer migrants start to leave, the closing of the nights brings the return of winter visitors to our shores. Late September into October sees the return of the quiet chatter of thousands of geese back to the shores of the Solway and Western Isles. Islay is a particular stronghold for barnacle geese, with around 30,000 overwintering on our shores.
It is quite something to witness the geese returning to the island after their summer hiatus. Last autumn I was lucky enough to be undertaking a wetland bird survey the day many of the geese returned to our shores. Walking down from the top of Loch Gruinart, a tidal sea loch, inland to survey wetland birds, hundreds of geese were flying overhead down the loch, congregating on the salt flats at the head of the loch, with many birds sleeping after their long journey - it certainly was a special sight to witness!
For many years the disappearance of thousands of geese in April and their reappearance in October led to much confusion around how the barnacle geese reproduced. The geese nest mainly on cliffs and in remote locations in Greenland meaning no one had seen a nest or young geese. This led to several theories, a long-standing one being that barnacle geese were hatched from trees! This particular theory was borne from timber washing up on west coast shores that had attached to it small creatures the same colour as the geese, with a small fluffy tongue that was likened to the downy feathers of young geese. This creature came to be called gooseneck barnacles, with the ‘fluffy tongue’ in fact being their feeding filament. The Latin name for these barnacles, Lepas anserifera, actually translates to ‘goose-forming’!
It was thought that the barnacle geese gained the nutrients they needed to grow from the sap of the wood or, as described by Royal clerk Giraldus Cambrensis, ‘from the sea by a secret and most wonderful process of alimentation’. (Barnacle Geese: The curious tale of the bird which people believed grew on trees - Country Life)
This theory of the origins of barnacle geese was even recorded in the Exeter Books of Riddles, in the 11th century:
‘My beak was close fettered, the currents of ocean running cold beneath me. There I grew in the sea, my body close to the moving wood. I was alive when I came from the water clad all in black, but part of me white. When the living air lifted me up, the wind from the wave bore me afar.’
As well as drifting in on timber it was also believed that the geese were the ‘fruit’ of waterside trees; with the young geese hanging from the branches by its beak. During Lent and on Fridays, the Irish clergy would eat the geese, justifying it as fruit and not flesh! Word spread to Pope Innocent III and in 1215 he removed the geese from the menu, saying that as the geese lived and fed like ducks they should therefore be classed and treated as birds! (Barnacle Geese: The curious tale of the bird which people believed grew on trees - Country Life)
Other stories from Irish folklore tell of the early arrival of the geese signifying a hard or severe winter. (Irish Folklore for Ireland’s winter visitor the Barnacle Goose – thefadingyear (wordpress.com)). In present day, it is our influence on the weather which is likely to be impacting the geese. This is especially true for a goose species which undertakes a similar migration to the barnacle geese, the Greenland white-fronted goose, one of the Species on the Edge target species. Lesser in number and more elusive, these geese travel and feed in complex family structures and are site faithful. Flocks of geese are usually made up of extended families of several generations. (Greenland White-fronted Goose International Action Plan (unep-aewa.org)). Their Latin name, Anser albifrons, means ‘white forehead’ describing the flash of white feathers around the base of the bill.
Greenland white-fronted geese have seen a 47% decline in their population from the late 1990s to 2015 (SNH Research Report 912: Conservation management of Greenland white-fronted geese Anser albifrons flavirostris on Islay, Scotland (nature.scot)), with low productivity meaning their birth rate has not kept pace with mortality rate. Here on Islay numbers fell by 70% over the same period. The reasons for this are unclear, though contributing factors include disturbance, loss and modification of wetland habitats where they feed, and hunting pressures (though the geese are now legally protected from hunting in nearly all of their world range). They are also being affected by the climate crisis, with changing weather affecting their nesting sites. Warmer springs in Greenland bring an increase in snowfall, affecting feeding grounds and nesting areas. The expansion of neighbouring nesting Canada geese are also putting pressure on nest sites for the white-fronted geese. (Greenland White-fronted Goose International Action Plan (unep-aewa.org)).
Back on Islay the Species on the Edge programme will be helping to track movements of the geese through reading goose rings – a ring with a number that can be seen through a scope from a couple of hundred metres. This reduces disturbance to the geese and allows us to track movements of individuals and family groups over many years. It’s quite exciting when you start recognising individual geese from their ring combinations, and realising they’ve made an epic journey twice over since you last saw them! The fields at RSPB Loch Gruinart will soon be filled with their chitter-chatter as they settle back into their winter home.
Lucy Atkinson is a Species on the Edge Project Officer for Argyll and the Inner Hebrides employed by RSPB Scotland and based on the Isle of Islay.