Army Corps tries to lure common terns back to the nest

May 27, 2014

The common tern used to nest in great numbers in the lower Great Lakes region, including Michigan, Pennsylvania, and Ohio. But in recent decades, common tern nests and their brown speckled eggs have largely disappeared from the region. 

Uncommon terns

In the 1960s, it was common to see common terns around the Great Lakes. They used to nest by the thousands around Lake Erie. The graceful seabirds have long, pointed wings, and have what looks like a black cap over their head and eyes. They’re known for hovering over the water, then plunging in to catch fish in their orange-red bills.

Tom Fredette is a research biologist with the U.S. Army Corps of Engineers.

“The tern is a small, diving water bird. It’s a very good aerialist. It is very effective at maneuvering.”

He says the common terns’ flight skills may help in its recovery around the Great Lakes. Terns still migrate through this region, but they’re now considered endangered, threatened, or ‘of concern’ in most Great Lakes states.

Pesticides and egg-stealing raccoons are problems for them, and more adaptable ring-billed gulls have taken over many tern nesting sites.

“Basically, a loss of suitable nesting habitat as the area was developed. People have built on the shoreline, and all of those things have eliminated areas where they historically nested,” says Fredette.

The Army Corps is usually known for working with dams and flood protection. But Fredette says they’re also trying to bring common terns back to this section of Lake Erie.

"The phrase we're using is 'engineering with nature.'"

“It is a new idea. It’s an initiative the Corps of Engineers started a few years ago. The phrase we’re using is 'engineering with nature.'"

Inticing terns to nest

We’re standing on the shoreline. Fredette points to large concrete walls off the distance, in the lake. They’re called breakwaters. He says they were built more than 100 years ago, to slow down the water, and help boats navigate safely into the harbor. But some are crumbling, and the Army Corps has been repairing the walls. Fredette says in the process, they’re trying to help terns.

They’re using a $300,000 grant to create special nesting areas for common terns in Lake Erie.

Fredette says they'll be broadcasting tern calls to draw the birds to the breakwaters.

When they get there, the terns will see gravel and driftwood strewn around. The Corps has also placed decoy terns and small wooden shelters on the tops of the large concrete walls. It looks kind of messy, but the terns like it that way.

Karen Adair is with the Nature Conservancy, which is helping with the project.

"In natural habitat, there'd be driftwood, there'd be shrubs, rocks, there'd be all sorts of things the chicks could get shelter from. Because this is an artificial structure, we have to provide that protection," she says.

Because the walls are so far out on the water, the tern nests should be protected from varmints, and they’re surrounded with mesh fencing, to keep tern chicks from running over the edge.

Tern parking only

Competition for nesting sites is tough among birds. Tom Fredette says the Corps is using cables to make the nests a bit difficult to get to. The idea is to give the common terns a wing-up, by taking advantage of their special abilities to hover and dive.

“Terns are acrobatic enough that they can make it down through that to the nesting site, whereas the cormorants and gulls aren’t able to do that. So, that’s one of the ways we’re going to try to keep the area reserved just for the terns,” says Fredette.

Fredette says this kind of project has worked in other places, like Buffalo Harbor. He says once these nests are fully constructed, it could take a year or more, but he expects the common terns will return.

The bird calls in this story are from the Macaulay Library at the Cornell Lab of Ornithology; they were recorded by Randolph Scott Little and Charles A. Sutherland.