1. A piping plover chirps and walks on the rocky beach of Sleeping Bear Dunes National Lakeshore
2. Various of a plover safely ensconced in a wire enclosure set up on the beach
3. Various of Vince Cavalieri, piping plover coordinator for the U.S. Fish and Wildlife Service, and other officials preparing to observe the birds
4. SOUNDBITE (English) Vince Cavalieri, U.S. Fish and Wildlife Service:
"The Great Lakes piping plover is kind of a flagship species for this entire ecosystem. And, by protecting the Great Lakes piping plover and its habitat, you're really protecting the Great Lakes dunes ecosystem as a whole."
5. A plover walks in and near the water
6. A sign made by a child that reads "Save The Piping Plover" hangs on the beach
7. Three plovers walk along the beach
8. Grass sways in the wind near a pond that has swelled in size this year
9. SOUNDBITE (English) Vince Cavalieri, U.S. Fish and Wildlife Service:
"The habitat that they utilize has been greatly diminished by the high water. The high water levels put them in danger for a number of reasons like washouts and putting them close to predators."
10. A plover walks into an enclosure and settles in
11. Various of a posted sign warning that the area of the beach is a piping plover nesting area and closed to the public
12. A member of the public looks out at the water near the plover nesting area
13. Erica Adams, a National Park Service plover specialist, looks at plovers through binoculars
14. SOUNDBITE (English) Erica Adams, National Park Service:
"Keeping out of the plover habitat is absolutely paramount to the success of the plover population here at Sleeping Bear Dunes."
15. Waves crash down on the beach
16. Plover tracks in the sand
17. A plover walks by, then flies away
18. Cavalieri; Adams; and Alice Van Zoeren, a research assistant with a University of Minnesota team that bands plovers; walk along the beach
19. SOUNDBITE (English) Erica Adams, National Park Service:
"They are an absolutely phenomenal species. They represent so many great things about the Great Lakes and conservation and how people have come together."
Trouble is brewing for the piping plover, already one of the Great Lakes region's most endangered species, as water levels surge during a rain-soaked spring that has flooded large areas of the Midwest.
Pools are forming behind several nests along a beach at Michigan's Sleeping Bear Dunes National Lakeshore. And Lake Michigan has crept within a few yards of the plovers' nesting zone.
Their home could be one storm away from destruction. And this is one of the most hospitable spots for the plump, sparrow-sized shorebirds. Conditions are worse elsewhere.
The Great Lakes are reaching some of their highest levels since the U.S. Army Corps of Engineers began keeping records 101 years ago. Many beaches are shrinking or submerged.
For piping plovers, it's a mortal threat. Squeezed out of familiar turf, they move closer to places with trees and underbrush, where predators lurk, or even flee to urban areas.
"The habitat that they utilize has been greatly diminished by the high water," said Vince Cavalieri (CAV'-eh-LEER'-ee), piping plover coordinator for the U.S. Fish and Wildlife Service. "The high water levels put them in danger for a number of reasons like washouts and putting them close to predators."
The Great Lakes generally rise with the snowmelt and rainstorms of spring and dip during later dry spells. Those minor fluctuations happen within larger high and low periods that can last years.
But some scientists believe climate change is causing more frequent and intense shifts.
If so, the piping plovers' situation could become more precarious. Their numbers already have plummeted with shoreline development. The federal government lists them as threatened in the northern Great Plains and along the Atlantic coast, where rising sea levels imperil their wintering grounds. But the Great Lakes population is endangered, hitting a low of just 12 breeding pairs in 1990.
Recovery projects are helping; 76 pairs were counted in 2017 and 67 last year. This year's census is still underway but expected to yield similar results.
The next few weeks are crucial. Most of this year's eggs will hatch by the end of June. If additional storms don't wash away nests, a new batch of youngsters may survive.
But long-term prospects will be dicey until the waters recede.
Piping plovers are a migratory species, breeding during summers in the northern U.S. and Canada and heading south to winter in coastal areas from the Carolinas to Texas.
Once settled in, they spend lots of time on the ground _ building nests, guarding eggs, darting about in search of food such as insects, spiders and crustaceans. Their plumage, a mixture of light browns and grays with a black collar, provides camouflage.
At Sleeping Bear Dunes, home to nearly half of the Great Lakes plovers during spring and summer, breeding grounds are roped off and posted with keep-out signs. Nests are topped with cage-like enclosures that bar entry to predatory merlins, gulls, raccoons, foxes and coyotes but leave enough space between the wires for the plovers to enter and exit.
In addition to serving as security guards, professionals and volunteers can perform emergency rescues if flooding is imminent.
"They are an absolutely phenomenal species," said Erica Adams, a National Park Service plover specialist. "They represent so many great things about the Great Lakes and conservation and how people have come together."