A Bird’s Tale

Hurricanes and Birds

Wed, 09/13/2017 - 9:30am

As we send good thoughts to the human victims of hurricanes Harvey and Irma, we consider also the other lives that are affected by these massive storms. Keeping to the topic of birds, we’ll start by noting that birds are impacted in many ways from hurricanes both directly and indirectly. Even some that are far from the hurricane are eventually impacted by its effects.

It’s no surprise that when a hurricane passes over an area, birds are caught up in its winds. Hurricanes with very strong winds, like those that Irma was packing when it went over much of the Caribbean, can be lethal. Unlike us humans, birds have no hurricane-proof buildings within which to retreat. Land birds in particular have no place to which they can evacuate. Birds can be blown into obstacles or have trees or limbs or other objects blown into them. There are some heartbreaking videos on the Internet of dead and dying flamingos that were hit by Hurricane Irma in Cuba. No one yet knows the fate of the yellow and blue-gray Barbuda warbler whose entire world population, estimated at no more than 2,500 individuals, is confined to the tiny island of Barbuda, which endured devastating winds that destroyed almost all homes there. In 1989, when Hurricane Hugo raked over Puerto Rico, it killed half of the population of the already critically endangered Puerto Rican parrot, dropping the population to only 23 birds. That same hurricane went on to hit South Carolina, where it smashed through longleaf pine forests and killed an estimated 65 percent of the threatened red-cockaded woodpeckers in the Francis Marion National Forest.

Birds that survive the hurricane may find their habitat decimated. The red-cockaded woodpeckers that survived Hurricane Hugo’s winds found that most of their nesting and roosting cavity trees had been snapped in two or knocked over. Luckily for the woodpeckers, a massive rescue effort was mobilized to build and set up hundreds of artificial cavities for the survivors. Numbers stabilized and then increased.

Some birds are already flying or are forced to take flight by being blown into the air by the hurricane. Sadly, many likely are blown into the water and drown, but others are able to stay aloft, perhaps almost aerially dodging the bands of particularly strong wings. Those that make it into the center of the hurricane and find the calm air of the eye are said to be “entrained” by the hurricane. For their best chance of survival, they must continually move with the eye until the hurricane winds near the eye drop enough to make it possible to fly away or stop for a rest. In a slow moving hurricane like Irma, one can only imagination the exhausted birds trying to fly continually for days.

Birders often go out immediately after a hurricane passes to look for species that were carried along by the hurricane either in the eye or blown along on the edge. We remember seeing a normally strictly oceanic wilson’s storm-petrel on Cayuga Lake in Upstate New York, hundreds of miles from the sea, after the passage of the remnants of Hurricane Isabel there in 2003.

Other birds may just skirt the edges of a hurricane and either be stalled in their southbound migration or speeded up by the stronger winds. A friend from Aruba emailed us that he had seen four blackpoll warblers on Aruba around the time that Hurricane Irma was near the northern Lesser Antilles. We wondered whether the birds may have almost been flung forward by being caught in migration along the western edge of the hurricane where the winds are pushing south.

Some birds, perhaps waterbirds and shorebirds, may find more wetlands, at least temporarily, in the aftermath of heavy rains from Hurricanes Harvey and Irma. But billions of birds migrating south in the fall on their way to the southeastern U.S., the Caribbean, and Central and South America may find very different conditions in some of the places that they stop over or where they normally spend the winter. For some, the habitat may be destroyed and they will have to move on and find new places. In this way, they are not unlike too many of the people who call the region home. Our hearts go out to all of them.

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology. Dr. Wells is one of the nation's leading bird experts and conservation biologists and author of the “Birder’s Conservation Handbook.” His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the book, “Maine’s Favorite Birds” and the just-released “Birds of Aruba, Bonaire, and Curaçao.”