Anyone with Blackbirds in garden asked to take action 'immediately' as 'days left'
The Usutu virus, which is transmitted by mosquitoes, has been spreading through Blackbirds in southern England but a crucial survey to help is almost finished
The deadly Usutu virus - a mosquito-borne disease that has been ravaging Blackbirds across southern England - is sparking alarm amongst wildlife experts.
Initially detected on British soil in 2020, the virus has now advanced westward to Dorset and pushed northward into Cambridgeshire. Hailing from Southern Africa, Usutu arrived in Europe three decades ago, where it has triggered multiple catastrophic Blackbird die-offs, Bird Guides revealed.
The British Trust for Ornithology is now urging all garden owners with blackbirds to participate in a specialised survey to assess the scale of the destruction and provide assistance where required - but there are only days left to participate as it ends in early September.
While the danger to humans stays minimal – with zero confirmed cases in Britain – the effect on bird populations is devastating. Statistics show that across Greater London, Blackbird numbers have crashed by as much as 40% since Usutu's arrival following the 2020 heatwave.
Dr Arran Folly from the Animal and Plant Health Agency (APHA) sounded warnings about the virus's swift expansion and persistent presence, indicating it might herald other mosquito-transmitted illnesses reaching Britain. "It gives an indication that in the future we might get other viruses that are transmitted by mosquitoes emerging in the UK," he warned.
Blamed on climate change, mosquito population explosions are being driven by soaring temperatures, extended summers, and heavier downpours – creating perfect conditions for both the bugs and their deadly diseases to thrive in places they previously couldn't survive.
Teaming up with the British Trust for Ornithology (BTO), APHA scientists plan to investigate Usutu's devastating effects on our native bird species more thoroughly.
Meanwhile, the BTO is calling on Britons to help monitor the crisis by reporting Blackbird sightings.
"Blackbirds are currently nesting and are a common sight in gardens and parks. With public help, we can better track population trends and the virus's impact," a BTO spokesperson declared.
While Blackbird numbers remain stable in countryside and northern regions, the unpredictable nature of the virus demands constant monitoring.
The combined efforts of APHA and BTO seek to deliver crucial information to guide conservation measures and brace for future emerging illnesses.
The BTO revealed: "We are trying to better understand the extent and spread of Usutu virus and what the potential impacts of the virus might be on Blackbirds. In particular, as Blackbird numbers were already decreasing in London, a large urban area, we want to know if anything similar is happening in other urban areas, or whether these changes are specific to the capital, and how this compares to smaller urban and more rural areas."
How will Blackbirds in Gardens help?
The British Trust for Ornithology (BTO) is conducting a survey to understand the potential for disease transmission by Blackbirds in gardens, examining the number of birds that congregate together. The organisation stated it will help comprehend how Blackbird's use of different types of gardens varies, and how successfully young can be raised, particularly at varying levels of urbanisation from rural to urban gardens.
The BTO warned: "Although largely harmless to humans, this is the first time in modern history that a mosquito-borne viral zoonosis (a disease which can be transmitted from animals to humans) has emerged in wild animal hosts in the UK but, with changing climates, more may occur in the future.
"Using Usutu virus and Blackbirds as a case study, this survey is part of the Vector-Borne RADAR project, a wider partnership project funded by the UKRI and Defra to understand the emergence and transmission of mosquito-borne viruses in the UK more generally which are expected to increase with climate change.
"The project will improve understanding of how these viruses emerge in new environments, enhance surveillance of diseases in wild birds in the UK and develop an early warning system for disease outbreaks."
How to sign up to the survey
You can sign up for Blackbirds in Gardens online.
- You will need a My BTO account to sign up. If you don't already have one, you can create a free account.