Birds play an outsized, underappreciated role in shaping Earth's chemistry, distributing nutrients across oceans, forests and coral reefs and sustaining life far beyond the nest. Researchers from Cornell and five other institutions reviewed nearly 400 scientific papers to show how birds transport nutrients from land, lake and sea through their waste and bodies. This influences everything from soil and water chemistry to plant and animal growth. The work was published Oct. 19 in Current Biology.