Families Urged To Help Protect UK Blackbirds As Mosquito-Borne Virus Spreads

UK families are being urged to act in their gardens as the deadly mosquito-borne Usutu virus threatens blackbird numbers nationwide.

Ecologists at Arbtech are calling on households to make small changes that can have a big impact on protecting one of the most recognisable and best loved garden birds in the country. Data has revealed a 40% decline in blackbirds in Greater London since the virus was first detected in 2020 – and with climate change helping mosquitoes expand their range, experts warn the problem is only set to grow.

Carried by the Culex pipiens mosquito (the common house mosquito), Usutu virus does not affect humans in the UK, but is often fatal to birds – especially blackbirds, which are particularly vulnerable to infection. With longer summers, warmer temperatures and heavier rainfall creating ideal breeding conditions for mosquitoes, ecologists are warning that climate change is helping diseases like Usutu gain a foothold in the UK for the first time. The virus is now well established in Britain’s wild bird population, and further declines in some species are expected unless action is taken to limit additional pressures like habitat loss and food scarcity. Now, ecological experts at Arbtech are encouraging families to support one of Britain’s most common garden visitors, whose numbers are under threat. 

A spokesperson for Arbtech commented: “Blackbirds are more than just a familiar visitor to our gardens – they’re important seed dispersers and insect predators, helping to regulate pest populations and support healthy ecosystems. But they’re under real pressure. Diseases like Usutu virus, which can cause tremors, disorientation and even sudden death in infected birds, are an emerging threat – and many people still don’t realise the impact it’s already having. The good news is that households with even a small garden can make a real difference. Simple actions like planting native shrubs, providing clean water, and avoiding pesticides all help create safer, healthier habitats for blackbirds to feed, nest and thrive.“

Seven ways to help protect blackbirds in your garden:

1. Plant for shelter and food

Growing native trees and shrubs like hawthorn, dogwood or elder gives blackbirds cover and natural food sources. You can also leave some leaf litter or logs to encourage insects for blackbirds to eat.

2. Offer fresh water daily

Birds need clean water for drinking and bathing. Use shallow dishes or birdbaths and scrub them out regularly to avoid the spread of disease.

3. Avoid pesticides and chemicals

Slug pellets and weedkillers harm insect populations and can poison birds. Instead, try to choose organic or wildlife friendly alternatives.

4. Disinfect feeders and tables

Clean all bird feeders and feeding stations at least once a week to reduce the risk of spreading disease between birds.

5. Report signs of disease

If you spot sick or dead birds, report it to Garden Wildlife Health or the Animal and Plant Health Agency (APHA), as early reporting helps track outbreaks like Usutu. Symptoms of Usutu virus in blackbirds can vary, but infected birds often show signs of serious neurological and physical distress. Common symptoms include lethargy or weakness, loss of coordination, unsteady movement, disorientation or unusual behaviour (like not fleeing from humans), tremors, seizures, and fluffed-up feathers – a common sign of illness in birds). 

6. Build wildlife corridors

Leave gaps in fences or plant hedgerows to help blackbirds and other species safely move between gardens.

7. Source garden products carefully

Imported bird boxes or bee hotels may introduce pests or pathogens. Choose UK made or naturally sourced items where possible.