What happens to migrating birds during a hurricane?
Every fall, thousands if not millions of birds migrate southward through Cape Island. Cape May Bird Observatory monitors certain species daily. Most birds wait for favorable winds and weather before starting a migratory flight, so they seldom strike out over water during a hurricane, but some birds may be well offshore when a storm begins.
Hurricane Florence made land fall last Thursday near Wilmington, North Carolina with wind gusts over 90 miles per hour.
“For birds that get caught up in the actual hurricane a few things can happen, they die, rare, but it happens. More common if they get caught in the storm and taken out to sea. Some simply get displaced,” said David La Puma of the Cape May Bird Observatory.
The typical weather pattern in fall is cold fronts moving from west to east, when they clear the coast northwest winds build in conveying birds south and east. As birds get pushed to the coast they concentrate at places like Cape May because for the most part they don’t want to be over the Atlantic Ocean.
He said Pelagic birds (seabirds) can get caught up in the eye of a hurricane because the weather in the eye is calm, relative to the very strong winds that make up the eye wall, so pelagic birds caught up in the eye can be deposited on land once a storm makes landfall and loses energy.
“This can result in some very weird inland records for otherwise oceanic species like albatross, frigate birds, storm petrels, petrels, and others. La Puma said. “Sometimes we find dead seabirds after storms, which suggests that it’s not all peachy out on the high seas in the face of a hurricane, but we pretty much knew that anyway.”
“When we get these storms making landfall, it’s usually because there is no cold front to sweep it away into the North Atlantic, and we lack the northwest winds,” La Puma explained. “What we often end up with are east or northeast winds, which push the southbound migrants inland.”
Migrating Birds in Hurricanes
During Hurricane Sandy in 2012, Pelagic birds were seen in Pennsylvania at Beltzville State Park, according to David Hawk of Lehighton Pennsylvania. “We saw Jeagers and Phalaropes” Hawk said. Hawk was visiting Cape May in hopes of spotting birds in advance of the storm.
Such displacement can happen if they are migrating, hit opposing winds, and instead of grounding themselves, simply get caught up in the opposing wind field and carried off somewhere they didn’t intend. This happens as birds get “wrapped” around hurricanes and big storms during migration and results in things like “overshoots” where birds migrate too far in the correct direction (typically more noticeable in spring) or “reverse migrations” where birds end up going back towards (and sometimes beyond) the latitude from which they came.
When it comes to pelagic birds, though, hurricanes can often produce some very interesting results. which is why you often see birders out during and following a storm!
“We do have concerns about storms like Florence and how they might impact birds that aren’t migrating, “said Kashi Davis, biologist with the New Jersey Department of Fish and Wildlife. “Piping Plovers an endangered species uses North Carolina as the northern edge of their wintering grounds,”
Plovers winter down both coasts of Florida and in the Bahamas according to Davis.
“What worries us is the sustained period of rain, the volume of rain and storm surge. A lot of Plover habitat will be under water.” Davis said. “We know that some of the New Jersey breeding Piping Plovers are already tucked into their winter locations although we don’t know exactly how the birds respond to hurricanes.”
Biologists are wondering if the fitness of New Jersey birds is not as good as surrounding states and so other birds had an easier time surviving nasty weather conditions last year. With an active hurricane season last year New Jersey saw a low return rate among its banded population of birds.
“In any case, it gets scary (for me!) for endangered species because they can’t absorb the loss of individuals the way a stable, healthy population can, said Davis. “We will anxiously be awaiting reports of our birdies, once people can start surveying again, however long it takes before water recedes.”