North American birds are declining faster and that signals risks for people.

A study in Science finds many North American bird species are declining at accelerating rates, with average counts down about 304 birds per survey route (roughly a 15% drop) since the late 1980s; declines are strongest in warmer areas and regions of intensive agriculture.

Scientists report that many North American bird populations are shrinking and that the rate of loss is increasing year by year. The finding comes from analysis of long-term counts collected on standardized survey routes across the continent. Researchers note the steepest declines occur in warmer regions and where agricultural intensity is high. The study frames these changes as a potential indicator of broader environmental problems that also affect people. Key facts: - Researchers analyzed long-term Breeding Bird Survey data and found an average decline of about 304 fewer birds per route since the late 1980s, roughly a 15% drop in abundance. - Of 122 species with declining populations, more than half showed accelerating rates of decline rather than steady losses. - Areas with stronger warming and more intensive cropland and pesticide/fertilizer use tended to show the largest, fastest declines. Summary: The study signals likely cascading effects for ecosystem functions that depend on common bird species, such as pollination, seed dispersal and insect control. Undetermined at this time.