Rare hummingbird sighting ignites twitter among Miami birders

South Florida has a way of attracting vagrants and for birders, that's a good thing.

This month, a tiny hummingbird that typically migrates between Texas and Mexico mysteriously took a detour and made a very rare appearance in Miami-Dade County. Birders, who call such stragglers vagrants, quickly flocked to Castellow Hammock Nature Center, a remote county park with a few scattered benches and little hint of its ranking among naturalists as prime grounds for spying trophies. Painted buntings routinely turn up in the South Miami-Dade park. Once over a few days in 2004, three amethyst hairstreak butterflies were spotted.

In recent days, the sighting of the buff-bellied hummingbird lit up bird boards and sparked rumors of a possible “irruption.” In the birding world, this would be very good news indeed.

Irruptions occur periodically, and rarely this far south, when changes in weather or other conditions drive birds off course and into regions where they’re hardly ever seen. Another birder spotted about a dozen scissor-tailed flycatchers near the Southern Glades Trail on the edge of Everglades National Park this month. That bird normally migrates between Central America and Texas and Oklahoma. On Wednesday, one was still visible cutting through the air, trailing Seussian tail feathers. American robins, which typically don't range this far south, have also turned up in the eastern Everglades recently.

It’s too early to tell whether actual irruptions for some species are occurring and whether enough will occur to constitute a very rare “superflight” or mass irruption. Or, more likely, it could just be a busy year for vagrants. In any event, birders say it’s turning out to be a good year.

“It’s definitely been an interesting year in Florida in terms of rarities,” said Brian Rapoza, a Tropical Audubon board member and author of Birding Florida. What with a variegated flycatcher from the Amazon showing up in Evergreen Cemetery in Fort Lauderdale and northern wheatear veering offtrack to Islamorada on its way from Greenland, both in October and November, Rapoza said birders “didn’t know which way to go.”

Florida has its fair share of hummingbirds, but naturalist and author Roger Hammer said about 99 percent of what people see are ruby-throated hummingbirds. Sometimes rufous hummingbirds — the males are a brilliant cinnamon — will make an appearance. In 1981, Hammer spotted the first pair of Bahama woodstars in Florida at the Mary Krome Bird Refuge in Homestead. The next day, the sighting of the island hummingbird, known for its distinct humming sound, made headlines in the Miami Herald and, Hammer said, drew “a crowd of 300 people from Connecticut to California. That was a life bird for a lot of people.”

Hammer, who worked as a naturalist at Castellow Hammock for more than three decades, helped make it a bird and butterfly mecca by planting juicy blooms including native firebush and a Chinese hat plant that now stands about 15 feet high and covers about 35 feet, which likely drew the buff-bellied.

Earlier this month, a birder from Colorado spotted a hummingbird near the bush but wasn’t able to identify it. So she snapped a picture and contacted Steve Backes, a Tampa birder who maintains a website to collect information on hummingbirds in Florida. Backes got in touch with a pair of birders from Tropical Audubon, who posted it on the group’s bird board and voila, the flocking commenced. When word reached birders in the midst of the annual Audubon Christmas bird count in Coot Bay Jan. 2, they went running.

“People just abandoned their post and went running after this bird, including me,” Rapoza said.

The buff-bellied typically migrate between Texas and Mexico. Why it ended up here is a mystery. Rapoza and Hammer suspect it got sidetracked flying south along the coast to Mexico and instead wrapped around the bend into Louisiana and south to Florida. Another theory is that hummingbirds hitch rides on the backs of turkey vultures, Hammer said.

“That’s totally goofy, but how could you disprove it?” he said.

Across South Florida, unusual bird sightings in recent years appear to be up, said David Webb, a nature coordinator for Miami-Dade County’s EcoAdventures. Recently, birders spotted a yellow-bellied flycatcher and Nashville warbler at A.D. Barnes park. While he has no hard data, Webb said “it really is a trend we’re seeing.”

The sightings this year could also have something to do with unusual weather that has gripped much of the country. Irruptions are typically linked to such weather patterns, said David Bonter, Assistant Director of Citizen Science at the Cornell Lab of Ornithology.

“A lot of birds that breed in boreal forests in Canada rely on tree seeds and every once in a while there will be a massive failure in seeds and the birds irrupt and are forced to move south to find food,” he said.

In October 2012, redbreasted nuthatches made their way into Central Florida during one of the biggest superflights in a decade. Two years ago snowy owls irrupted across the Great Lakes, the northeast and south. Irruptions usually occur cyclically, Bonter said, driven by El Niños or the North Atlantic oscillation, that can change weather patterns.

Most birds likely to irrupt never make it as far as South Florida, but there are three birders keep an eye out for: American robins, American goldfinches and cedar waxwings. American robins can be particularly interesting because of their weakness for Brazilian pepper. The plant’s berries are high in alcohol and robins are known to over indulge.

“I’ve never seen one intoxicated but from my understanding they’ll be on the ground, staggering around,” Rapoza said. “They look drunk.”

Hummingbirds are a little more discreet. Able to fly up to 80 mph, the buff-bellied can be hard to spot, so Hammer said it’s best to listen. When they’re feeding or flying, they make a mouse-like chirping sound.

“When you hear that,” he said, “then start looking around because you’ll hear them before you see them.”

This story was originally published January 8, 2016 at 7:18 PM with the headline "Rare hummingbird sighting ignites twitter among Miami birders."