The New York Times: “Birds in the United States are not only declining, but they are declining faster, especially in areas with intensive agriculture, according to new research. Overall drops in bird population, measured from 1987 to 2021, were sharpest in warm and warming areas, suggesting that climate change may play a role. The study, published on Thursday in the journal Science, shows only correlation with intensive agriculture and temperature, not causation. It does not factor in other circumstances that may be affecting birds along migratory routes or while they are overwintering. But it adds to an ever more robust body of evidence that birds — one of the best measured families of animals on Earth, and a sentinel for the health of other species — are not OK…The researchers also found that bird declines have sped up over time. On average, each route lost what amounted to an additional quarter of a bird per year compared with the previous year. While that change may sound small, accelerating declines can quickly snowball. For example, a 25-mile route that lost roughly 10 birds per year early on was losing around 19 birds annually by the end of the 34 year period, said François Leroy, a postdoctoral macroecology researcher at Ohio State University and the study’s lead author. When the team analyzed and mapped the rates of decline, hot spots of acceleration lit up in California, the Midwest and the Mid-Atlantic region. “We were quite surprised to see those patterns,” Dr. Leroy said. The team decided to add further analysis, using statistical modeling to look for associations. Among 20 metrics, they looked at fertilizer use, pesticide use and area of cropland. “What we found is that any metric of agricultural intensity was always the best predictor of acceleration of the decline.”…