migrator

The study focused on birds that move at night, as most migrators do, particularly perching birds such as warblers, thrushes and sparrows.

Fecal pellets from vertical migrators, rich in carbon, descend through the water column.

Some animals prey on ungulates, and numerous organisms depend on the biological activity sparked by hooves and the spreading of seeds and other material in migrators’ urine and feces.

The finding adds to evidence that migrators don’t always head back and forth between two fixed points, but instead follow food and avoid floods, fires, and other disturbances.

Scientists also agree that changing light intensity is the primary environmental cue for migrators, says Heather Bracken-Grissom, a marine biologist at Florida International University.