Steep declines of widespread and previously numerous bird species in the US is concerning conservationists.
Overall, North American bird populations have plummeted by 30 per cent since the 1970s, mirroring a similar trend in the UK, according to the 2025 US State of the Birds report.
But it is the trend among common and abundant birds that is worrying scientists such as Amanda Rodewold at the University of Cornell’s Lab of Ornithology.
“We are talking about species that should be able to live alongside us,” Rodewald says. "This should wake us up because we know from our history with the loss of the passenger pigeon how an abundant species can reach a tipping point.”
The passenger pigeon was once one of the most numerous birds on the planet with an estimated population of up to 5 billion individuals, but over-hunting in the 19th century made it extinct in the wild by 1900.
Grassland birds have been particularly badly hit, with populations decreasing by 43% in the past half a century. In the American mid-west, there are an estimated 320 million acres (130 million hectares) of grasslands, but these are being lost at a rate of 1-2 million acres (400,000-800,00 hectares) a year. Birds showing the steepest declines include the mountain plover and Baird’s sparrow.
Wildfowl such as ducks have largely recovered since the 1970s, except in the last decade when numbers have begun to drop again. Again, even common species such as mallards and northern pintail are not immune to these trends, says Rodewald.
Commenting on the reasons for the declines, Rodewald cites a multitude of factors. “Agricultural intensification and the conversion of grassland – and that’s modified grassland not native prairie – to crops is a major cause,” she says. Intensification can be anything from greater use of pesticides to loss of hedgerows.
Climate change is another issue, leading to droughts that have hit species in North America’s so-called 'aridlands’ – biomes such as the Mojave and Sonoran Deserts and its shrub-steppe habitat.
"Climate change is a more direct drive of change for seabirds and shorebirds,” Rodewald says. "It’s changing sea currents [leading to loss of prey species] and sea level rises are flooding out breeding colonies on low-lying islands.”
The report argues that the annual economic output generated by activities related to birds and birding is estimated to be $280 billion (£250 billion), making the case for increased federal and state expenditure on wildlife conservation.
Main image: northern pintail. Credit: Getty
More wildlife stories from around the world
- See world’s first-ever wild jaguar translocation in Argentina
- Here's why 15 giant birds were just released into Patagonia National Park
- DNA reveals extraordinary way ancient iguanas made epic 5,000-mile journey to Tonga and Fiji
- We already knew chimpanzees were smart – but new research shows their engineering prowess exceeds all imagination
