Winter Migration

As the days shorten and the first crisp frosts touch the moors around Rannoch, the Highlands prepare to welcome a great wave of winter visitors — birds that have bred far to the north and east and now turn south to escape the advancing Arctic winter. These are not birds fleeing Scotland; they are coming to it, seeking the milder maritime climate, open water, and rich feeding grounds that our islands offer when the lands further north lie locked in ice and snow. Among the most numerous and dramatic are the geese — vast skeins of them appearing high over the pass of Rannoch, their haunting calls drifting down before the birds themselves are seen. Pink-footed Geese pass over in their thousands, forming great V-formations that stretch across the sky, bound for the fertile coastal plains and estuaries of the east coast — places like the Montrose Basin, the Ythan Estuary, and the broad farmlands of Angus and Aberdeenshire. That distinctive V-shape is no accident: each bird rides the updraft of the wingbeat in front of it, saving vital energy on journeys that can stretch for hundreds of miles, taking turns at the point of the formation so no single bird bears the brunt of the lead for too long. It is a marvel of aerodynamic efficiency, allowing them to travel immense distances without tiring. These geese have come from their breeding grounds in central Iceland and eastern Greenland — places where the short summer gives way to months of freezing temperatures and permanent darkness — and they arrive in Scotland seeking the open grassland, stubble fields, and root crops that remain accessible throughout our comparatively mild winter.

Some of our most familiar birds reveal a surprising complexity in their movements, with mixed populations that behave in very different ways. The Greylag Goose is the perfect example: the native Scottish population is largely resident, remaining here to breed and never straying far from their home lochs and glens. But every autumn they are joined by vast numbers of Greylags that have bred in Iceland — birds that travel across the North Atlantic to winter in Britain, swelling our local flocks to many times their original size. So when you see a Greylag on Loch Rannoch in winter, it may be a bird that hatched locally and will stay to nest in the spring, or it may be a traveller from a volcanic island far out in the Atlantic — and in many cases, it is impossible to tell them apart. This pattern is repeated in other species too: the Wood Pigeon, so abundant around the loch, includes both resident birds and migrants from the continent; Mallard and Teal may be locals that never leave, or arrivals from Scandinavia and the Baltic; and even the Robin, our constant garden companion, may be joined in winter by birds from northern Europe that move south to find food. In spring, the pattern reverses: the Icelandic Greylags return north to breed, leaving our native birds behind — a quiet, invisible separation that happens every year without fanfare.

Beyond the geese, the lochs and woods of Rannoch welcome a host of other winter visitors. Whooper Swans arrive from Iceland — larger, noisier, and more elegant than our resident mute swans — seeking unfrozen freshwater and grazing on the shores of lochs and fields. Their wild, bugling calls carry far across the water, a sound that marks the true beginning of winter. From the far north of Scandinavia and Russia come Wigeon, handsome ducks that whistle softly as they graze on the grassy margins of Loch Rannoch and the lochans of the moors, fleeing the ice that seals their breeding lakes. Goldeneye — sleek, diving ducks with brilliant white patches on their wings — arrive from the boreal forests of northern Europe, seeking the open, nutrient-rich waters where they can dive for insect larvae and molluscs. From the high Arctic islands come Redwings and Fieldfares, the northern thrushes, descending upon the berry-laden bushes of rowan and hawthorn when the ground hardens and worms vanish beneath the frost. They have left the taiga and tundra far behind, where the sun no longer rises above the horizon, and come to feed on the fruit that remains on our trees long after the leaves have fallen.

Birds of prey also move with the changing seasons. Hen Harriers from the north descend to the lowlands and moorland edges, while Short-eared Owls — those ghostly day-flying hunters — arrive in numbers from Scandinavia, quartering the rough grasslands in search of voles and small birds. Even the tiny Goldcrest, our smallest bird, is joined by continental migrants; and the Brambling, a close relative of the chaffinch, appears in the birch woods, seeking the beech mast and seeds that become scarce further east. What unites them all is the search for liquid water and accessible food — the defining advantages of our island climate. While the lands they leave behind freeze solid and lie in darkness for months, Scotland remains relatively open, its lochs rarely sealed by ice for long, its grasslands still green enough to graze, its berries and seeds still clinging to branches. They are not fleeing our weather — they are fleeing much worse weather elsewhere, and coming to a land that, for all its rain and wind, offers them life through the winter.

In spring, the great reversal begins. The Pink-footed Geese and Icelandic Greylags turn northward once more, retracing their V-formations over Rannoch toward the Arctic. The Whooper Swans depart for Iceland, the Wigeon and Goldeneye for the boreal forests, the Redwings and Fieldfares for the taiga. And they leave behind them our own native birds — the resident Greylags, our local Mallards, our breeding Robins — who never left at all. It is a remarkable, overlapping tapestry: one population arriving while another stays, one departing while another remains, making the birdlife of Rannoch in winter richer, more numerous, and more deeply connected to distant lands than we might ever imagine.