Imagine a dawn so loud with birdsong that it wakes your children. That was Britain in 1976, when house sparrows chirruped, starlings chattered, and blackbirds fluted with the clarity of a piccolo. Naturalist WH Hudson in 1919 was grateful a thrush perched far from his home, lest its “shrill indefatigable voice” blast him awake at 3:30 a.m. Poets Shelley, Keats, and Clare all tried to capture the skylark’s delight and the nightingale’s “chee chew chew chew.” But today, those sounds have gone quiet in many gardens. In the last 50 years, Britain has lost 73 million wild birds, according to the British Trust for Ornithology (BTO).

“What we have is a shifting baseline,” says Dr Rob Robinson, a BTO senior scientist. “People engaging in nature today think the numbers they see are normal. But 50 years ago, they would have experienced a much richer environment.” The Guardian has recreated the dawn chorus across decades to show what we’ve lost since the abundance of the 1970s. In April 1976, Labour’s Harold Wilson resigned as PM; today, political manoeuvrings are similar, but the soundscape is utterly changed.

This “shifting baseline syndrome” is, according to nature writer Robert Macfarlane, “an enormously powerful and pernicious psychological mechanism whereby each new generation measures loss from the degraded baseline it grew up into.” Ralph Pite, a University of Bristol professor, was 14 in 1976 and remembers kids being woken by the dawn chorus, “excited and enthralled. Today that vividness has gone.”

Human intervention - housing, commercial development, industrial agriculture, monocultures, pesticides, pollution, and climate change - has decimated bird habitats. The house sparrow population has crashed by over 72% since 1976, the starling by 88%, according to the BTO. Both are now on the UK red list of conservation concern, along with the greenfinch, swift, house martin, tree sparrow, cuckoo, and nightingale.

Robinson notes that losses were steepest in the late ’70s, ’80s, and early ’90s, then continued at a lower but consistent rate. “Specialist species like the lesser spotted woodpecker and red-backed shrike have disappeared from southern England, while generalists like the wood pigeon thrive. So we are seeing a huge loss in abundance.” Abundant birds indicate healthy habitats; their loss signals environmental decline.

Susan Morgan, CEO of SongBird Survival, warns: “A quieter dawn chorus tells us something is going wrong. Once lost we may not get it back.” New threats include the Usutu virus, affecting blackbirds in southeast England and Greater London, first seen in Britain in 2020 and linked to climate change. Garden bird trichomonosis is hitting greenfinches. The RSPB pleads with bird lovers not to feed birds from May to October, as feeders can spread disease.

Colin Butler, a civil engineer from Wallsend, recalls far more starlings and house sparrows in his youth. “I associate morning birdsong with peace and an anything-is-possible mindset.” Yet some optimism remains. The Merlin app, created by the Cornell Lab of Ornithology, identifies birds from song in real time, getting people involved. Robinson says, “But the nature they are getting involved with is much poorer than it was 50 years ago.”

Joella Manley, 27, an ecologist from Nottingham, is part of a growing younger cohort taking up birdwatching. “Birds make every day better.” Macfarlane reminds us: “It is not enough to love the song and forget the singers. There is such hard work needed from government, business, and individuals to help birds thrive.”