Humanity's close relationship with birds extends back tens of thousands of years. From helping us fish and hunt, providing us with soft comfort on which to sleep, to being our early long-distance messengers, these modern dinosaurs have gifted us with many incredible services, beyond merely being food, throughout our entire existence.
But one in six birds has quietly vanished across Europe since the 1980s, a new study has concluded. This amounts to a staggering loss of up to 620 million individual birds in the last 40 years.
"What's worrying is that it's been happening almost unnoticed, invisibly, quietly in the background," Richard Gregory from the Royal Society for the Protection of Birds (RSPB) told NewsChain.
Seemingly ubiquitous, adorable little sparrows have halved in numbers since the '80s and there are now nearly 75 million fewer inquisitive and clever starlings mimicking the sounds of the world around us - a decline of 60 percent.
Most of the declines have occurred in species associated with agricultural and grassland environments, but it's also happening in our cities too.
"Common birds are becoming less and less common, largely because the spaces they depend on are being wiped out by humans," explained Anna Staneva, BirdLife Europe's Interim Head of Conservation.
"Nature has been eradicated from our farmland, sea and cities. Governments across all of Europe must establish legally binding targets for nature restoration, otherwise, the consequences will be severe, including for our own species."
Causes are likely to be varied and numerous, including habitat loss, the massive decline in insect species, pollution, and disease – all the usual suspects contributing to the wider mass extinction event we're experiencing.
The house sparrow has been worst hit, losing 50% of its population - 247 million birds.— RSPB Science (@RSPBScience) November 16, 2021
Changes in agricultural policy and management have driven declines, however urban populations are also declining which may be linked to food shortage, avian malaria or air pollution
For now at least, this loss of birds is primarily from abundant species, with a 25 percent decimation of common species and a 4 percent loss in rare species, so it hasn't resulted in many extinctions as yet.
However, "common species are likely to contribute disproportionately more than rare ones," the researchers, lead by RSPB conservation biologist Fiona Burns, warned, so even relatively small losses can massively disrupt our ecosystem's structure and function due to the loss of the vital services these birds provide.
Our rich history of birdwatching has meant population studies of birds are some of the most well developed of any group of animals. We have heaps of historical data thanks to amateur ornithologists guided by professionals, which the current study puts to good use.
Using information from two such databases, Burns and colleagues took into account 378 of 445 native bird species that breed in Europe.
Previous smaller studies already detected these worrying declines across Europe - sadly this trend held true across a wider range of species and the wider time frame considered by the new study. In 2019, a similar study in North America found the same is happening there too.
All this research points "to a failure to achieve existing biodiversity targets and call for transformative change across sectors of human society as an emerging Post-2020 Global Biodiversity Framework takes shape," the team wrote in their paper.
It wasn't all bad news, though. Burns and colleagues found that many instances of population increases, such as the doubling seen in peregrine falcon populations, were due to conservation efforts. Seven species of birds of prey bucked the trend thanks to a reduction in persecution, pesticides, and increased protection.
This goes to show just how powerfully we can shape biodiversity deliberately as well as incidentally.
"We need transformative action across society to tackle the nature and climate crises together," said Burns. "That means increasing the scale and ambition of nature-friendly farming, species protection, sustainable forestry and fisheries, and rapidly expanding the protected area network."
In light of these findings, the researchers urge for the instigation of proposed EU nature restoration law.
We can also help individually by providing locally native vegetation in our gardens, planting trees, putting up nest boxes and even carefully providing the right types of food through the harshest parts of winter.
"Providing the right kind of seeds for birds can make a big difference for their survival and their populations," Gregory told NewsChain.
"Spring is going to be so much quieter without birdsong if it carries on in this fashion, and we don't do something urgently to turn things around."
This research was published in Ecology and Evolution.