SAVANNAH, Ga. -- Threatened by development and predators from every side, local birds here are finding safe, pristine habitats in an unlikely place: at the bottom of the Savannah River.
As part of environmental mitigation for the Savannah Harbor navigation project, the U.S. Army Corps of Engineers Savannah District uses sediment dredged from the river to create islands along Savannah’s Back River.
The islands – four elliptical sand-covered strands ranging from four to eight acres each – are nestled within dredged material containment areas, or DCMAs, and designed to encourage threatened species of birds to nest and proliferate.
Biologists like Savannah District’s Ellie Covington already see positive results.
“There are definitely more birds here since last week. Just by the noise you can tell there are more,” she said on a recent visit to Jones-Oysterbed Island.
During nesting season, from April to August, Covington and fellow Corps biologist Mary Richards make weekly treks to each of the containment areas, along with three trips a month to Tybee Island, to count birds and assess the health of these habitats. Their daily routine is far from ordinary.
A day at the office
It’s early morning and Covington bumps along in a four-wheel drive, all-terrain vehicle in a containment area at Jones-Oysterbed Island. Clad in snake boots, camouflaged pants and a lavender shirt, she stops to set up 100 yards from the edge of the cheese puff-shaped island.
Through her spotting scope she quickly counts and documents a variety of species of birds before moving to a different vantage point. Two threatened species from Georgia and South Carolina, least terns and Wilson’s plovers, show promise.
According to Covington, last year the island in containment area 12A hosted the largest colony of least terns in South Carolina. In May, she and Richards counted approximately 450 pairs, which is more than 40 percent of the least terns nesting in the entire state. The same island boasts the largest colonies in South Carolina for black skimmers and gull-billed terns, which are listed as a species of concern, a classification just below threatened.
It’s no accident the birds are flocking to these islands. Each of the islands is surrounded by a 50-foot moat, which keeps raccoons and another of the birds’ primary predators – wild hogs – at bay. The islands also mimic birds’ preferred habitat, bare-ground sand.
Historically, Covington said, least terns and Wilson’s plovers would have been found all along the Georgia-South Carolina coast, but development has forced them out of those areas.
“Other than wildlife refuges or bird sanctuaries, you don’t really find them,” Covington said.
Back at Jones-Oysterbed Island, fuzzy Wilson plover chicks scurry through ankle-high underbrush. The parents make sharp calls as if to say, “Danger! Hide!”
The main types of birds, including black-neck stilts, least terns and Wilson’s plovers, have sorted themselves into separate areas on the island. Wilson’s plovers and least terns stay higher up toward the middle of the island, while black-neck stilts remain closer to the water. Covington commented on how territorial stilts are as a pair took turns circling her 30 feet up, squawking continuously.
“They’ll drive you mad,” Covington said.
Looking back through her scope, she smiles.
A male least tern on the northern end of the island has partially swallowed a fish more than half its size. The fish’s tail extends another six to eight inches out of the tern’s beak, which Covington called “a little ambitious.” A few feet away, another male waves a fish back and forth in front of a seated, uninterested female.
Males exhibit this behavior to attract mates and show they can bring home the herring. Covington also noted how the islands allow different species of birds, which have unique nest-building styles, to coexist.
In addition to counting and observing birds, the Corps sometimes makes adjustments to entice more birds to nest.
Last year biologists noticed the island within containment area 13A was overgrown with grass and the Corps applied herbicides. The birds, particularly least terns and gull-billed terns, took note and returned.
Further upriver near Port Wentworth, Onslow Island is gearing up. Workers completed construction last spring on a two-acre bird island set in 120 acres of water. Corps biologists are working with the U.S. Fish and Wildlife Service and the Georgia Department of Transportation to attract threatened species like least terns and Wilson's plovers to the site, but right now black-neck stilts, herons, ducks and other shorebirds are foraging there.
“It’s the first year the area has been available since the late 1990s, so maybe next year more birds will find it,” Covington said.
There’s no doubt the islands are providing a valuable habitat for birds that have been impacted by development along the coast. And the number of birds biologists are observing implies that the word is spreading. But the islands are also providing intangibles to others outside the bird community.
“It’s the best part of my job. Every day I see something different and learn something new,” Covington said. “It clears your head to get out of the cubicle farm.”