Seabirds choose to poop mid-flight, not on water, study explains strange ritual

Seabirds choose to poop mid-flight, not on water, study explains strange ritual (Image: Canva)

On Japan’s remote islands, researchers have uncovered an unusual ritual among seabirds. Streaked shearwaters prefer to poop while flying, not while floating on water.

Shearwaters Reveal Peculiar Flight Habit

The discovery was published in Current Biology on 18 August. Scientists strapped tiny cameras to 15 shearwaters and recorded nearly 200 defecation events. They found that the birds relieved themselves almost exclusively in flight, often shortly after takeoff. At times, they took off just to defecate and quickly returned to the sea.

Lead author Leo Uesaka from the University of Tokyo said the habit first appeared amusing but later revealed ecological importance. The birds released droppings every four to ten minutes, adding up to around 30 grams an hour. That equals about five per cent of their body weight.

Researchers believe the behaviour may prevent the birds from fouling their feathers or drawing attention from predators. Their long, narrow wings make takeoff tiring, suggesting a strong reason behind avoiding defecation while floating. Uesaka explained that excreting mid-flight may also be easier than while resting on the water surface.

Impact on Marine Ecology

Seabird droppings are rich in nitrogen and phosphorus, nutrients that fertilise ecosystems. While their effect on coastal areas is known, less is understood about open seas, where shearwaters spend much of their lives. With an estimated millions of shearwaters globally, their feces could provide important nutrients for plankton and other sea creatures.

Uesaka now plans further studies using GPS and advanced sensors to map defecation patterns at sea. He hopes the research will deepen understanding of how seabird waste influences marine ecology. “Feces are important,” he said. “But people don’t really think about it.”