IT’S AN ILL WIND...(10/02/03)

Hugo, Floyd, Camille, Andrew, Georges, Gloria, Bob. Do those names and others recall unpleasant memories? They should, as these were powerful hurricanes that produced damaging losses to human life and property. Fortunately, Isabel is not among them, at least not in New England.

Despite the dire facts I’ll explain below, “it’s ill wind that blows no good.” Like many other events in life, hurricanes have a two-pronged effect. Although such storms are often devastating, arriving during sensitive periods in birds’ lives, scientists learn a lot about the effects of strong storms on all forms of wildlife, and birdwatchers actually hope for such a happening!

You might not believe this, especially if you’ve ever been caught in the teeth of a gale, but these atmospheric disturbances create exciting circumstances that allow those on land to have close encounters with bird species seldom seen except at sea.

Although Isabel’s winds in our area were not strong enough to bring in these pelagic species, such as shearwaters and jaegers, close to shore, I was prepared to brave the winds at either (or both) Sandy Neck in Sandwich and First Encounter Beach in Eastham, two of the best vantage points, in order to enjoy the experience. Even though this proved to be a nonevent for us, I thought you’d be interested in knowing about big storms and their effects on wildlife, especially birds.

Despite the massive changes to wildlife habitats of barrier islands, coastal marshes and forests that hurricanes often cause, their impact on natural systems in the Caribbean and along North America’s Atlantic coast, which have weathered hurricanes for thousands of years, are greater today because of human-related influences. When large tropical storms cross the Caribbean and the Gulf of Mexico, their damaging effects are magnified by the increased settlement and subsequent human-caused disturbances to coastal and island ecosystems.

In Louisiana, for example, the shrinking of fragile wetlands and an estimated loss of 25 percent of its seagrass bed habitats, has resulted in 20,000 redhead ducks losing a good portion of their winter feeding grounds and forcing Sandwich terns and brown pelicans to go elsewhere for nesting. The toll extends to the loss of oysters and other bottom-dwelling organisms — important food sources for herons and other wading birds — as well as fish and sea turtles that depend on the seagrass.

Although there may be some structural changes in the habitat and drastic losses to populations of plants and animals, most of those living in storm zones are able to survive and recover in time from the severe weather. However, the changes in habitat as a result of a storm make birds more vulnerable to predators.

What happens to our migrating birds whose seasonal journeys usually coincide with the hurricane season? We can hope that Isabel was just late enough (as was the case when Hurricane Floyd hit the Atlantic coast in 1999 on approximately the same date as Isabel’s visit) to spare the endangered Northeast breeding population of roseate terns from destruction as they went along the mid-Atlantic coasts.

The terns may have dodged the path of the hurricane, as they should have been well on their way from their summer staging area on the Cape to northern South America, where they overwinter. However, we won't know for sure until next summer or even for several years, when the censuses of the major colonies on the East coast in New York, Connecticut, Massachusetts and Maine are completed.

It took many years for scientists to measure the full effects on roseate terns from the effects of Hurricane Bob in the fall of 1991. They learned that Bob almost doubled the death rate of over-wintering adult roseate terns, and that only about five percent of the young terns from that year survived and eventually entered the breeding population in later years.

Not only are terns’ movements affected by hurricanes, shorebird migration is no doubt seriously disrupted by them, and it is possible that many coastal species that had moved south and were feeding along the Maryland and North Carolina coasts were pushed to far-inland sites. We may learn of many sandpipers, plovers, knots and others that ended up feeding and roosting in agricultural fields to the west, while oceanic birds may have appeared in strange places, having been wind-carried miles inland.

And what of our songbirds during a violent storm? Many stay on the ground and under cover, sitting tight until the storm passes. Others may be blown out to sea, where they perish unnoticed in the deep oceans. Some might find temporary refuge and rest on ships, but without food it is doubtful these birds would survive more than 24 to 48 hours.

We can hope that our hurricane season is over for this year, but we know that sooner or later we won’t be as lucky as we were this time. When that happens and you are preparing your home to withstand the forces of the wind and rain, think about the wildlife and hope that all are either not in the wrong place at the wrong time or that they are able to find safe refuge.

Please send your comments and anecdotes about birds to me in care of the Cape Cod Times, 319 Main Street, Hyannis, MA 02601 or, if you use email, to emiller@seepub.com. I regret that because of an overwhelming amount of mail, I cannot respond to each of you personally. However, I have added a Frequently Asked Questions (FAQ) section to the web page with my current and past bird columns, now found at http://home.comcast.net/~elliemiller/index.html. If you can’t find the answer to your question there, try Bird Watcher’s Digest at 1-800-879-2478 or check out their FAQ at www.birdwatchersdigest.com.

GRAPHIC: Parasitic Jaeger Courtesy of Blair Nikula, Chatham