From 79 swans to 32 in a single year
At St Margaret's Loch in Edinburgh's Holyrood Park, twenty swans have perished from suspected avian influenza, reducing a population of 79 to just 32 in the span of a year. The outbreak is part of a wider pattern moving through Scotland's waterways and wild places, complicated by the weakening effects of blue-green algae on the birds before the virus even arrives. Most unsettling is what this moment may signal beyond the birds themselves: the virus has already crossed into UK mammals, finding new hosts in otters and foxes, and quietly testing the boundaries of the species barrier.
- A beloved urban flock has been cut by more than half in a single year, with swan carcasses accumulating in the water of a public park until rangers were deployed to remove them.
- The outbreak is not isolated — control zones spanning three and ten kilometres have been activated near Crossgates in Fife, and similar zones were triggered across Scotland in January, from the Highlands to Dumfries and Galloway.
- Blue-green algae at sites like Linlithgow Loch is suspected of pre-weakening birds, leaving their immune systems compromised before the virus arrives — a toxic one-two punch that has proven catastrophic.
- For the first time in Britain, avian influenza has jumped to mammals, with otters and foxes testing positive since 2021, raising urgent questions about how the virus is adapting.
- Authorities are urging the public to stop feeding birds, avoid dead wildlife, and keep dogs away from congregating flocks — small human behaviours that could determine how far the virus travels next.
Twenty swans have died at St Margaret's Loch in Edinburgh's Holyrood Park from what authorities believe is avian influenza. The loss is stark in its scale: a year ago, around 79 swans lived in the area; today roughly 32 remain. Historic Environment Scotland has deployed a ranger team to remove bodies from the water, and warning signs now ring the loch asking visitors not to feed or approach the birds. Hilary Thacker, who works with local swan and goose study groups, noted that deaths appear to have slowed in recent days — but the damage is already severe, and the same pattern has emerged at Linlithgow Loch nearby.
What makes the outbreak particularly troubling is the suspected role of blue-green algae in weakening the birds before the virus takes hold. Thacker observed that algal exposure leaves swans with pink-tinged feathers and a compromised immune system. Linlithgow Loch is severely contaminated with the algae, and the combination of toxic bacteria followed by a lethal virus has proven devastating for local populations.
The virus has spread well beyond Holyrood Park. A highly pathogenic strain was confirmed on February 2nd near Crossgates in Fife, triggering protection and surveillance zones around the site. Similar control zones were established across Scotland in January, from Aberdeenshire to Dumfries and Galloway. More alarming still, avian influenza has now crossed into UK mammals — otters and foxes have tested positive since 2021, marking the first documented species jump of this kind in Britain. Authorities are urging the public to avoid touching dead or dying birds, keep dogs away from bird congregations, and above all, stop feeding the flocks — each precaution a small but meaningful barrier against further spread.
Twenty swans are dead at St Margaret's Loch in Edinburgh's Holyrood Park, killed by what authorities believe is avian influenza. The bodies have been accumulating in the water long enough that Historic Environment Scotland has had to mobilize a ranger team to remove them. Signs now ring the loch warning visitors to keep their distance from the birds and, critically, not to feed them.
The scale of the loss becomes clear when you look at the numbers over time. A year ago, roughly 79 swans lived in this area. Today there are around 32. The die-off has been swift and concentrated. Hilary Thacker, who works with the Friends of the Water of Leith Basin and assists with the Lothians and Fife swan and goose study group, told reporters that the deaths seem to have slowed in recent days—no new ones for a few days, she said—but the damage is already done. The same pattern has appeared at Linlithgow Loch, where swan deaths have also been reported recently.
What makes this outbreak particularly troubling is the suspected role of blue-green algae in weakening the birds before the virus arrived. Thacker observed that the algae leaves swans with distinctive pink feathers and compromises their health. Some birds survive the algal exposure, but they emerge fragile, their immune systems already compromised. Linlithgow Loch, she noted, is severely contaminated with the algae. The combination—toxic bacteria followed by a deadly virus—has proven catastrophic for the local population.
The bird flu itself has already spread beyond the park. A highly pathogenic strain was confirmed on February 2 at a premises near Crossgates in Fife, triggering the establishment of a three-kilometer protection zone and a ten-kilometer surveillance zone around the site. Similar control zones were activated across Scotland in January—in Dumfries and Galloway, Clackmannanshire, the Highlands, and Aberdeenshire—as the virus moved through the country's bird populations.
What has alarmed public health officials is that the virus is no longer confined to birds. Otters and foxes across the UK have tested positive for avian influenza since 2021, marking the first documented jump of the virus to mammals in Britain. The implications are still unfolding, but the crossing of the species barrier suggests the virus is adapting and spreading in ways that were not previously seen. Historic Environment Scotland's warning is straightforward: do not touch dead or dying birds, keep dogs away from areas where birds congregate, and above all, stop feeding the flocks. Each of these actions reduces the chance that the virus will find new hosts or spread further through the remaining population. The situation at St Margaret's Loch may be stabilizing, but the larger outbreak across Scotland shows no signs of stopping.
Notable Quotes
The blue-green algae leaves them with pink feathers. Some survive, but it has weakened them.— Hilary Thacker, Friends of the Water of Leith Basin
Our ranger team are working to remove any dead birds as soon as practicable and have installed signage around the loch advising visitors to avoid touching any dead or dying birds.— Historic Environment Scotland spokesperson
The Hearth Conversation Another angle on the story
Why does feeding the birds matter so much right now? Wouldn't people want to help?
Feeding brings birds together in closer contact. When they're crowded around food, the virus spreads faster. It's the opposite of help.
And the blue-green algae—is that something that could have been prevented?
Possibly. It's a water quality issue. The algae thrives in certain conditions. If the loch had been managed differently, the swans might have had stronger immune systems to fight off the flu.
So they were already sick when the virus arrived?
Not sick exactly, but weakened. The algae damages them. Then the flu comes, and they have nothing left to fight with.
What does it mean that otters and foxes are catching it now?
It means the virus is learning to jump species. We thought bird flu stayed in birds. Now we know it doesn't. That changes everything about how we think about containment.
Is there a risk to people?
Not yet, not directly. But when a virus crosses into mammals, the path to humans becomes shorter. That's why the zones are so large, why the warnings are so firm.
What happens to the swans that are left?
They survive in a depleted population. From 79 to 32. The ones that remain are the ones with some resistance, but they're isolated now, fewer to breed from, fewer to sustain the flock.