Seabirds Expel 5% of Their Bodily Mass Every Hour, a Practice They Perform Solely While Flying Across the Ocean

In a groundbreaking study published in the journal Current Biology, researchers have revealed that seabirds, particularly streaked shearwaters, play a significant role in the nutrient cycle of marine ecosystems. The study, conducted by Leo Uesaka and Katsufumi Sato from 2021 to 2023 on Funakoshi Ohshima Island in Japan, has shed light on the birds' excretion habits and their impact on the ocean's health.

The study focused on the streaked shearwater (Calonectris leucomelas), a bird known for its aerial nutrient courier role. These birds offload packages of nutrients, rich in nitrogen and phosphorus, every few minutes as they fly, a process that may be maintained with a precise periodicity within a few minutes.

The researchers found that each bird poops every 4-10 minutes, losing around 5 percent of their body mass in droppings each hour. This frequent excretion, combined with the constant feeding and foraging while flying, could have a profound impact on the open ocean, rivaling the "whale pump" in terms of nutrient distribution.

The study also highlighted the potential risks associated with seabird excretion. Some streaked shearwaters may inadvertently spread viruses like bird flu by circling above and dropping feces on their companions. Understanding the frequency of defecation at sea is key to understanding the spread of viruses among flocks of streaked shearwaters.

On a positive note, pooping in flight may help keep the birds clean by reducing their exposure to pathogens like avian influenza. Furthermore, the payoff for this behaviour may be aerodynamic: flying with a lighter load is easier.

The study of bird legs has become an unexpected window into the secret circulatory system of ecosystems. Using tiny belly-mounted cameras, the researchers recorded nearly 36 hours of foraging trips, providing valuable insights into the lives of these aerial nutrient couriers.

Biologist Joe Roman stated that all species can play a role in the movement of nutrients between systems. In the case of seabirds, their excretion habits have a profound impact on marine ecosystems, demonstrating that even the seemingly mundane activities of these creatures can have far-reaching consequences.

In conclusion, the study of seabird excretion has revealed these birds to be some of the Pacific's most relentless fertilizer machines. The ocean's health depends not just on what animals eat, but on what they expel. As we continue to learn more about these fascinating creatures and their impact on our oceans, we gain a deeper understanding of the intricate web of life that connects us all.