Volunteer birders across the UK and Ireland will be among those taking part in the six-yearly international swan census this weekend, counting numbers of the countries’ two wintering species, whooper and Bewick’s swans.
The survey, which last took place in January 2020, aims to track changes in the populations of these charismatic wildfowl in the UK and Ireland. The whoopers have mainly travelled from Iceland and the Bewick’s from Siberia.
As its name suggests, the international swan census covers a wider area than most bird counts, surveying overwintering populations of Bewick’s swans in the eastern Mediterranean and central Asia, and whooper swans in Iceland, continental north-west Europe and around the Black Sea.
In recent years, the species’s fortunes have diverged widely. While the UK’s winter population of whoopers has almost doubled in the past quarter century, to 20,000 birds, during the same period Bewick’s numbers have plummeted, with only 700 birds reported in early 2025, almost all at a few well-known sites in southern England.
Ironically, climate breakdown may be the cause of the whooper swan’s rise – and the Bewick’s swan’s fall. The recent run of mild winters has improved the whooper’s survival rate, greatly increasing the Icelandic breeding population. Meanwhile, equally mild winters in Scandinavia and the Low Countries mean that many Bewick’s swans are no longer bothering to cross the North Sea to the UK and Ireland.
