Some seabirds don’t just survive storms. They mount them.
Striped shearwaters nest on islands off Japan sometimes heads straight for passing typhoonswhere they fly close to the eye of the storm for hours at a time, the researchers report in the Oct. 11 journal. Proceedings of the National Academy of Sciences. This strange behavior, not reported in any other bird species, could help striped shearwaters (Calonectris leucomelas) survive strong storms.
Birds and other animals that live in areas with hurricanes and typhoons have adopted strategies to weather these deadly storms (Serial number: 2/10/15). In recent years, some studies using GPS trackers have revealed that some ocean-dwelling birds, such as frigatebirds (lesser frigatebird) – it will take massive diversions to avoid cyclones.
This is an understandable strategy for birds that spend most of their time out at sea where “there’s literally nowhere to hide,” says Emily Shepard, a behavioral ecologist at Swansea University in Wales. To find out if shearwaters also avoid storms, she and her colleagues used 11 years of tracking data from GPS locators attached to the wings of 75 nesting birds on Japan’s Awashima Island.
Combining this information with data on wind speeds during typhoons, the researchers found that shearwaters caught in the open ocean when a storm blew in mounted tailwinds around the edges of the storm. However, others caught between land and the eye of a strong cyclone would sometimes deviate from their usual flight patterns and head toward the center of the storm.
Of the 75 shearwaters monitored, 13 flew within 60 kilometers of the eye — an area Shepherd calls the “eye socket” where the winds were strongest — for up to eight hours, following the cyclone as it headed north. “It was one of those moments where we couldn’t believe our eyes,” says Shepard. “We had some predictions about how they might behave, but this wasn’t one of them.”
Shearwaters were most likely to target the eye during the strongest storms, soaring with winds of up to 75 kilometers per hour. This suggests the birds could be following the eye to avoid being pulled inland, where they risk crashing to earth or being hit by flying debris, Shepard says.
While this is the first time this behavior has been observed in a bird species, flying with the winds could be a common tactic to conserve energy during cyclones, says Andrew Farnsworth, an ornithologist at Cornell University who was not involved in the study. the study. “It may seem counterintuitive,” he says. “But from a bird behavior perspective, it makes a lot of sense.”