For centuries, Zekiah swamp in Southern Maryland has been a place to disappear.

John Wilkes Booth ducked under the marsh plants after he assassinated President Abraham Lincoln in 1865; freedom seekers crossed the mudflats to escape slavery; bootleggers tucked their stills into coves to retrieve when the Revenuers weren’t around.

But it’s hard to hide when you’re a tropical bird with a beak like a baking spoon, feathers the color of Pepto-Bismol, and laser-beam eyes.

If the minds behind Dr. Seuss and Barbie decided to collaborate on a character, it might well look like the roseate spoonbill — the South Florida native that entered Zekiah’s edge in late June and has been delighting and vexing birders in an area known as Allen’s Fresh Run off Route 234 and U.S. 301 near La Plata, some 80 miles south of Baltimore.

Previous summers — hotter and wetter — brought an errant juvenile spoonbill or two north. Bombay Hook in Delaware hosted one; so did Masonville Cove in Baltimore and Huntley Meadows near Alexandria, Virginia. But the Allen’s Fresh spoonbills traveled in a group. There were six.

Mornings they foraged in the sulfur-smelling mudflats of the shallow and slow-moving tidal waters. By afternoon, they took up residence in a tall pine tree overlooking the busy two-lane road, swooping in and out of the marsh along with prehistoric great blue herons and resident eagles.

Birders spread the word; photographers posted daily shots of the birds’ antics and gave detailed directions on reaching the roadside kayak put-in. Allen’s Fresh Run has no bathrooms, no restaurants, no benches, no trash can, no walking paths — nothing more than a blink-and-you-miss-it pull-off. Still, the intrepid arrived, a dozen or more a day, hoping to see a bird that some had only spotted in Costa Rica or Belize or the Everglades.

“Because they’re so rare for this area, I couldn’t help myself,” said Guy DiRoma, a Howard County birder who waited with others for the spoonbills to emerge. After a few hours with no luck, they all left. But DiRoma came back after replenishing his water supply and getting some lunch. His persistence paid off. All six spoonbills were in the tree.

And yet, the birders’ excitement is tempered by questions with less-happy answers: Why are the spoonbills here? Will they come back? And what does the sextet’s appearance in a Southern Maryland marsh tell us about their future, and ours?

“I’ve heard everything from ‘They’re coming up here because they’re doing so well in Florida and there’s a surplus of young’ to ‘They’re coming up here because of the drought and there’s no food,’” said Tim Carney, a senior environmental specialist at the Maryland Environmental Service and an avid birder. “No one really knows but the spoonbills.”

One person with an inkling is Jerry Lorenz, who recently retired from Audubon Florida as director of research. Lorenz has been monitoring rising water levels in the Everglades for decades. Spoonbills need shallow water that recedes frequently to find food. In 2019, Lorenz told Audubon Magazine, the number of low-water days for the spoonbills — species name Platalea ajaja — had shrunk from six months to just two weeks.

Spoonbills have strong homing instincts, returning to breeding grounds year after year. But ornithologists note that they also practice “post-breeding dispersal,” or “vagrancy,” in their first year of life. Their parents send them out into the wild world to find food — and themselves.

Even that doesn’t explain why they chose a largely forgotten swamp, and in Maryland, to boot. The state and federal governments have spent millions of dollars restoring natural areas specifically for birds in places such as Poplar Island, Hart-Miller Island, and Blackwater National Wildlife Refuge.

“It’s a large freshwater swamp, so it likely reminds them of Florida,” said Kerry Wixted, a longtime ecologist who surveyed the Zekiah when she worked at the Maryland Department of Natural Resources.

Then, on July 16, things got weirder.

Four of the spoonbills flew north to Cecil County, landing at a stream behind a cemetery in North East. Social media was abuzz, but no sooner had birders made their plans to head out than the funky pink waders took flight again, this time for Chadds Ford, Pennsylvania.

Meanwhile, the two remaining birds stayed at Allen’s Fresh until July 17, then left, only to turn up in Indian Head near the Naval Surface War Center. Mike Hillmann, a retired Marine and avid birder, caught up with the spoonbills there, but they soon returned to Allen’s Fresh.

The birds’ feeding ritual reminds Hillmann of mine-sweeping — which the Marines do to make sure an area is clear of explosives. It’s thorough, repetitive, and utterly mesmerizing.

Jim Rapp, an avid birder who leads Delmarva Birding Weekends tours to Ocean City, Smith Island, and Delaware Bay, thinks the six spoonbills may portend a more permanent population. About 25 years ago, brown pelicans, native to Texas, came to Smith Island; now, there are thousands. Anhingas, painted buntings, and wood storks — all tropical birds — have started showing up in Maryland.

It’s a good-news, bad-news story, Rapp said. Bans on DDT saved many species, only to have rising sea levels and climate change drown their habitats. Maryland’s conservation measures may draw rare birds, but accelerated climate change may also mean they won’t be so rare anymore.

One thing is certain: we may have seen the last of the spoonbills, but we have not seen the last bird in an incongruous place — whether it’s Mississippi kites living it up at the Glen Burnie Costco or a lone snowy owl perching near downtown Cambridge.

“A lot of birds,” Rapp said, “are going places they didn’t used to be.”