Streaked shearwaters poop solely whereas flying over the ocean

This seabird poops on the fly.

Streaked shearwaters, oceanic birds that spend a lot of their day out on the open Pacific Ocean, defecate almost exclusively in the air, researchers report August 18 in Current Biology. Pooping in flight may permit these birds to keep away from wading in their very own feces, which might comprise pathogens similar to chook flu. The poop may additionally function ocean fertilizer.

Seabird guano gives vitamins to soil and water close to coastal nesting websites. But how shearwater poop impacts nutrient biking at sea is unclear. While whales transfer vitamins vertically in seawater by feasting in deep water and defecating on the floor, seabirds might “have a stronger local effect in areas where they gather in large numbers,” says biologist Leo Uesaka.  

Uesaka and behavioral ecologist Katsufumi Sato, each of the University of Tokyo, had taped cameras to the bellies of streaked shearwaters (Calonectris leucomelas) to review how the birds take off from the water. These cameras, going through backwards to seize the birds’ legs as they ran, additionally picked up once they pooped. “I was surprised to see how frequently the birds defecated in the video footage,” Uesaka says. “Enough that it became its own line of investigation.”

During practically 36 hours of recordings from 15 streaked shearwaters nesting on Funakoshi Ohshima Island off the coast of Japan, the crew captured 195 poops. Just one occurred whereas a chook was within the water. Uesaka suspects that was on account of unintentional intestine stress.

Defecating from the air might not solely assist the birds keep clear however may also scale back the danger of attracting predators to fecal plumes. In flight, these birds can poop each jiffy, shedding roughly 30 grams of mass per hour, or about 5 p.c of their physique mass. Frequent pooping might assist streaked shearwaters keep within the air with much less effort, Uesaka says, as a result of feeding can enhance the power wanted to fly.

These findings may assist researchers higher perceive how pathogens similar to chook flu transmit amongst giant teams of birds. While the virus can unfold inside colonies as birds nest on land, transmission amongst birds from totally different colonies is much less clear. Because the virus is transmitted by way of droppings, Uesaka says, “understanding the frequency of defecation at sea is key.”