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Nowhere to Tern by Victoria Parsons Chased from their ancestral nesting spots by beachgoers and their pets, least terns (Sterna antillarum) are making a surprising comeback on the flat white roofs of some Pinellas County buildings. However, even some of those unnatural habitats are being lost, leaving the least tern nowhere to turn. Once abundant across much of the Atlantic Coast, the least tern was nearly hunted to extinction at the turn of the century. About 100,000 birds were killed every year, serving a market that demanded snowy white feathers to adorn ladies' hats. The species recovered quickly after the Migratory Bird Treaty of 1918, but loss of habitat is once again threatening the least tern. Recognizing their plight, the St. Petersburg Audubon Society created a program to increase awareness of least terns and encourage businesses to allow the birds to nest on their roofs. The program, now in its second year, was selected as the best chapter conservation project for 2001 by Audubon of Florida. "We've gotten a better response than expected from most businesses," says Project Coordinator Monique Abrams. "A lot of people don't know what the terns are, or realize that they're desperate for nesting sites - all they see is bird droppings on their cars Once we tell them about the terns and their plight, they are much more sympathetic." Tiny Terns Fight to Survive
The nesting season begins with a courtship ritual in which a male tern offers a female a small fish - if she accepts it, they become mates and begin looking for a nesting site. Least terns are most successful in large groups, often 100 pairs or more. Ground-nesting birds, they count on protective coloration and numbers to discourage predators. Nests - really just shallow scrapes in the sand or rooftop gravel - can be as close as two or three feet, and as many as 200 nests can be found on buildings as small as gas stations. Both male and female birds take turns incubating the eggs, which take about 22 days to hatch. Once the chicks hatch, their parents fly dozens of sorties every day, bringing fish back to the nest. In very hot weather, they may fly home quickly to sprinkle chicks with cooling seawater from their feathers. The birds typically leave Florida for Latin America in June or July, flying in large groups. In Florida, populations may be rebounding - thanks to rooftop nesting sites - but the least tern is still listed as a threatened species which means it could become extinct if steps are not taken to ensure their long-term survival. Audubon Reaches Out to Businesses Pinellas County may have more least terns than any other county in Florida - or it may be that more volunteers are working to document their presence. When St. Petersburg Audubon began working with least terns in 1998, they knew of only three sites. Last year, with the help of more than 30 volunteers, they found and monitored more than 50 rooftop colonies. To find the birds, teams of Audubon volunteers drove up and down streets watching for clouds of white terns and listening for their distinctive call. When nesting sites were identified, building owners - many of whom had no idea the birds on their roofs were threatened with extinction - were given brochures and posters asking people to "please excuse the mess" the birds can cause. "We knew they were there, but we just thought they were cute little birds until the Audubon people told us what they were," says Kathi Alexander, office manager for Hall's Wholesale Florist in St. Petersburg. "We think it's really cool that they chose our roof since they're losing habitat on beaches." It's also great outreach for Audubon, says Bruce Ackerman, past president of the St. Petersburg group. "Mostly the people we talk to are already interested in birds and wildlife, but this project lets us reach people who may not have any interest and involve them in an important effort." Working with Dr. Elizabeth Forys and three of her students at Eckerd College, Audubon volunteers counted birds flying to and from roofs to estimate populations and spent three Sundays with a rented cherry-picker counting birds on 10 St. Petersburg rooftops to estimate populations on others. Because chicks can wander off roofs, or wash off in heavy rains, Audubon volunteers built a "chick-aboom" to place babies back on the roof without disturbing other nests They also worked closely with the Suncoast Seabird Sanctuary, which sends volunteers to pick up chicks that don't appear healthy enough to return to the wild immediately. "I think we all got hooked on these birds and feel the need to protect them," says Abrams. "You have to admire all the effort they go through to raise their chicks in an inhospitable environment." For more information or to schedule a presentation, contact Abrams at 727-894-3256.
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Least terns - so-called because they are the smallest of the terns - have gray and white bodies, a black-capped head, yellow bills and very short legs. Their wingspan is approximately 20 inches but they weigh only about 1.5 ounces. They arrive in Florida to nest in April or early May, after migrating from as far south as Peru and Brazil.