The first report came in on Monday. An Antillean Palm-Swift was spotted soaring above Grassy Key.
In the world of serious birders, that's big news.
"It's only the second record for North America," said Bill Pranty, who came from the Gulf Coast to see the bird on Friday. "The first one was 1972, so very few people who saw that bird are around. This is most people's first chance to see an Antillean Palm-Swift in the United States. So it's super-rare."
Others have come from as far as Texas and California to add the species to their life list.
"People collect birds this way they collect stamps or seashells. Or Hummel figurines or whatever. Most people collect something, and we just collect bird sightings," he said.
Don Fraser came from Dunedin to see the bird.
"This is a bird that I've never seen before and it's a great North American record," he said. "I moved to Florida from Canada three years ago and I'm kind of a born-again lister, which is what we call ourselves. I'm trying to see as many birds in Florida as I can."
Valeri Ponzo from Sarasota also made the trip on Friday.
"I am obsessive-compulsive and I like to see new birds. Actually I like to see new anything," she said. "I got a lifer butterfly this morning, an Eastern pygmy blue."
Antillean Palm-Swifts are commonly found in Cuba, Jamaica and Hispaniola. The previous U.S. sighting, from 1972, was in Key West.