Smaller bodies, longer wings, earlier migrations: Untangling the multiple impacts of climate warming

When a research team reported last year that North American migratory birds have been getting smaller over the past four decades and that their wings have gotten a bit longer, the scientists wondered if they were seeing the fingerprint of earlier spring migrations.

from Latest Science News -- ScienceDaily https://www.sciencedaily.com/releases/2021/06/210621084111.htm