A friendly if slightly tuneless chirp is the most ubiquitous birdsong in British gardens with the house sparrow topping the Big Garden Birdwatch charts for the 21st consecutive year, according to the annual RSPB survey.

Blue tits, starlings, wood pigeons and blackbirds were the next most-sighted birds by more than 600,000 participants in the world’s largest wildlife garden survey.

The long-running citizen science project provides conservationists with invaluable data on how common species are faring. Although an average of four house sparrows were spotted in every garden when the survey was conducted in January, the number recorded has declined by nearly 60% since the survey began in 1979.