What Do Animals Do When Hurricanes Approach?

MIAMI — People around the world have acquired knowledge from generations of deadly hurricanes, learning how to adapt and survive when fearsome winds and torrential downpours are in the area. Residents in the United States and beyond are privy to information like severe weather alerts, gaining precious preparation time to evacuate their homes or take safe shelter.

In contrast, fellow ecosystem inhabitants must rely on their natural instincts when a hurricane strikes. From some of the world’s most feared predators to smaller creatures in the animal kingdom, species have adapted in their own ways, absent of real-time information or alerts.

Animals who dwell under the surface are used to the water but are still wary of a hurricane’s potential impacts, finding ways to escape a hurricane’s wrath. In 2021, researchers from the University of Miami tackled marine life, including sharks, and their natural defenses that arise when a hurricane is en route. The research said that sharks and other marine life are sensitive to barometric pressure, which drops when a major storm such as a hurricane arrives. Sharks, in particular, can feel the change in pressure and will swim to deeper waters where they feel more comfortable.

“From two weeks out of a hurricane, sharks can actually detect the change and start heading for deeper water,” University of Miami Research Associate Professor Dr. Neil Hammerschlag told Popular Science. This detection was in need when the catastrophic Hurricane Ian landed in Florida last September, as sharks in the area sensed that air pressure in the area decrease before Ian’s landfall, giving the predator a chance to flee before mandatory evacuation orders were made.

The Miami researchers analyzed movement from tiger sharks, bull sharks, nurse sharks and great hammerheads during Hurricane Matthew in 2016 and Hurricane Irma in 2017, finding that most of the observed sharks evacuated shallow waters when Hurricane Irma impacted Miami. The exception was larger tiger sharks, which remained in dangerously shallow water in the Bahamas when Matthew hit.

Another round of research in 2019, led by marine scientist, Grace Casselberry, further proved sharks’ natural instinct to flee for more comfortable spots in the ocean. Casselberry and her colleagues tracked a variety of sharks in the U.S. Virgin Islands during Hurricane Maria in 2017, recording how they behaved when the storm arrived. The four different species of shark observed (tiger, lemon, nurse and Caribbean reef sharks) all moved to deeper waters during the Category 5 storm.

“When these big storms come through, you have a lot of wind, a lot of waves — a real chaotic environment,” Casselberry told Hakai Magazine. “We think they’re moving out to these deeper areas to take shelter from the storm.”

Bradley Strickland, a postdoctoral researcher at William and Mary’s Virginia Institute of Marine Science, added that sharks can use their sensitive inner ears to detect a storm’s pressure changes, and that the animal can use its quick swimming abilities to escape a storm’s wrath. “Aquatic animals respond to storms for the same reason we do — to avoid injury, death, and the destruction from hurricanes,” Strickland told Popular Science.

While aquatic animals can make quick evasive moves away from hurricanes under the surface, more airborne creatures such as birds must alter their entire life’s schedule to account for the storms. Like sharks, birds are also sensitive to barometric pressure and can also use infrasound cues to sense when trouble is on its way, the Journal of Experimental Biology reported.

Birds in the path of a hurricane, if they choose to leave, adjust behaviors based on both personal life histories and the time of the year. The white-throated sparrow, for example, may migrate sooner than usual if a storm is approaching, and move up an autumn migration date in response to falling barometric pressure.

Unlike sharks, however, more birds tend to fly right into the action. Research of a whimbrel bird’s movements showed that the bird flew into the danger zone of the devastating Hurricane Irene during its autumn migration from Canada to South America 2011. The same bird flew around the edge of Tropical Storm Colin the year prior. Another bird that researchers followed in 2011 flew into Tropical Storm Gert off the coast of Nova Scotia, Canada,and survived strong winds for 27 straight hours while it flew at 7 mph.

Birds have also taken shelter in the calmest part of hurricanes: the eye. In August 2020, while Category 4 Hurricane Laura crashed into the Louisiana coastline, radar images detected birds  in the eye of the storm congregated.

Birds that choose migration during a hurricane, particularly smaller birds, may have their flight paths altered by the powerful winds. In 2005, a large flock of smaller birds was diverted by the winds of Hurricane Wilma, and the flock was forced to relocate to Western Europe. Another flock of birds also relocated hundreds of miles from typical migration locations by Hurricane Matthew in 2016.

“Although storms can have short-term negative impacts on nesting shorebirds and seabirds, storms can often create new nesting habitat,” the Florida Fish and Wildlife Conservation Center said. “Hurricanes and tropical storms may change where shorebirds and seabirds nest in coastal areas, and give them space for the best chance at nesting success,” 

Non-migratory birds that decide not to fly during storms find a variety of shelters to ride out the event. A popular form of shelter for birds is inside thick bushes or trees, which help reduce wind speed and keep birds dry during downpours. Birds are more immune than other creatures to winds that would knock an animal off the trees or bushes since the species has adapted to sleeping while perched with tightly closed feet in order to hold on to solid branches.

Produced in association with AccuWeather

Edited by Kyana Jeanin Rubinfeld and Sterling Creighton Beard