March 11, 2026 | Source: The Conversation | by François Leroy

Since the 1970s, the U.S. has lost billions of birds. We now know that those losses aren’t just growing – they are accelerating in places with intensive human activity, particularly where agriculture and expanding communities are changing the landscape.

Bird population declines have been closely linked to pollution, use of chemicals and physical changes to their habitats.

But human pressures on nature are not just continuing; they are increasing at an accelerating rate. Indicators of human activity, such as population growth, economic growth and transportation use, rose more rapidly after the 1950s, as did measures of environmental change, from atmospheric carbon dioxide levels to tropical forest loss.

In a new study published in the journal Science, my colleagues and I found that bird populations are responding in the same way: Their declines are speeding up, particularly in regions dominated by intensive agriculture.