A volunteer, a state biologist and a Navy employee canoed out to three human-made nesting platforms on Lake Michigan along the Naval Station Great Lakes shoreline.
There, in mid-July, they witnessed the fruits of decades of sometimes seemingly hopeless labor.
Twenty-four common tern chicks were flying around their natal homes, with one more chick almost ready to fly. This was a banner year for the state-endangered species, with the largest number of young fledged in the state since 2004.
“It was exciting. Our hearts were in our mouths,” after the chicks hatched, said Donnie Dann of Highland Park. Dann, a volunteer, works with Brad Semel, a natural heritage biologist with the Illinois Department of Natural Resources and Taylor Bozman, natural resources manager at Naval Station Great Lakes, to help the terns.
They canoed out periodically the past several weeks to the human-made nesting structures erected two years ago to watch the chicks’ progress.
“We wanted to make sure they got bigger and they were able to fly,” Dann said. “This is of crucial importance. It’s a passion. I want to see these birds succeed.”
– Original Credit: News-Sun
The common tern is a white bird with a dark cap, a reddish-orange, black-tipped bill, a forked tail and streamlined-wings that help it dive headfirst into the water to catch fish.
They may be called common, but they are hardly common as breeders in the state.
Only colony in state
The Naval Station Great Lakes colony is the only remaining nesting colony for the terns in the state, according to Semel.
That adds to the importance of the Navy partnering with IDNR to protect the species, Bozman said. She said the Naval Station’s primary mission is to deliver sailors to the fleet, but it also is responsible for stewarding its natural resources. That’s why the Navy agreed in 2019 to help launch special nesting platforms for the terns.
Common terns have a long history of nesting in Illinois in small numbers, attempting to raise young on various lakeshore spots in Lake County. Nesting records go as far back as the late 1800s. Back then, feathers and sometimes entire terns were placed on women’s hats resulting in the near extirpation of these birds along the Atlantic coast where they also nest, according to Cornell Lab of Ornithology.
Their populations rebounded by the 1930s after the Migratory Bird Treaty Act was passed in 1918. Over the years in Illinois, there have been challenges and setbacks for the terns, including losses of entire colonies of young to predators, flooding, human disturbance and tainted fish.
– Original Credit: News-Sun
Lakeshore ambassadors
Just like the piping plovers, a federally endangered species that nests at Montrose Harbor in Chicago, common terns serve as ambassadors of the open lakeshore, Semel said.
“They’re trying to find these open sandy beaches in which to nest, and that’s where recreation and industrial development give them competition,” he said.
Terns and plovers move between sites to attempt nesting each year. It’s a strategy to avoid predators, he said.
“If they have no place to move to, they try over and over,” Semel said. “There are so few places to choose from.”
Protecting the terns is important, Semel said, because, “They are an integral part of the whole community of the lakeshore.”
In the past few decades, “I’ve literally chased them up and down the lakeshore” in Lake County, Semel said. “It’s been quite interesting to see them, where they’ve chosen to nest over the years. Each of those locations has proven to be a different challenge.”
Records show the terns have nested on settling ponds at an electricity plant in Lake County, as well as Naval Station Great Lakes, beginning in 2000, when Dann discovered them breeding there.
– Original Credit: News-Sun
Deterring predators
Dann and Semel got permission to work inside the Naval Station to watch the birds’ progress. In 2001, they counted 109 eggs. But no young survived. They were eaten by rats and likely dogs or coyotes. So in 2002, Semel installed a circular electric fence to keep out predators, and 26 young fledged.
Then in 2005, a mink found its way inside the colony and killed all but six of the fledglings. Semel did more fine tuning on the fence to keep out predators.
But in 2012, predators again got the first batch of eggs. Undeterred, the adults made a second nesting attempt. That, too, failed. All chicks died at hatching and the adults abandoned the colony.
Research showed that PCBs found in the fish the chicks were fed by adults interfered with their development, Semel said. A major cleanup since has been done along the lakeshore and PCB levels have dropped, he said.
Still, the years 2013-2018 were lean for the terns — with only three fledging in the entire state all those years.
In 2015, a new common tern colony was discovered along Waukegan Beach, but Semel said within a day after they were found, “there were AV tracks” at the site, and human disturbance likely caused the adults to abandon the colony. Semel added dogs running loose have also destroyed common tern nests, which are built atop the sand with a few sticks and some pebbles.
Semel even worked with an endangered species specialist to try to entice the terns to the beachfront by the Zion nuclear power plant, where it is well-protected and fenced.
“We had decoys (of terns) and callboxes (imitating the terns’ calls) to attract them,” Dann said. But that didn’t work.
– Original Credit: News-Sun
Nesting platforms
In 2018, the terns were back at Naval Station Great Lakes, but flooding was a problem. That led to the terns trying to nest on a boat dock by the naval station That gave Semel an idea. Why not create floating docks out of swimming platforms, and put fences around them?
An eagle scout helped construct the 10×12-foot platforms, which sit on floating buoys so they’re above the water.
“We covered the platforms with sand, and put in driftwood and other materials to make it look more natural,” Semel said.
Fifteen young fledged from the platform nests in 2019. But in 2020, when the terns came back, no chicks fledged. A great horned owl got them all.
With approval from the U.S. Department of Agriculture and the U.S. Fish and Wildlife Service, Semel trapped and relocated the owl to a state forest near Oregon, Illinois, where he said plenty of rabbits are available for them to eat.
“The result was a phenomenal year of good productivity this year,” Dann said.
Bozman said they have taken turns standing up in the canoe and hanging onto the platform’s fencing to get a count of the number of chicks, nests and adults. “It’s really amazing to see both the adults and young up close. The adults are very protective of the chicks, so it can get a little chaotic having them flying around us.”
Paddling out to see the terns, she said, is “a highlight of my workday.”
Semel said the Wisconsin Department of Natural Resources has had similar struggles and found refurbishing old pontoon boats for the terns, also endangered in Wisconsin, has proved successful.
Later this summer, when all the terns have left, Semel will work with Bozman and Dann to remove the nesting structures from the lake. He’ll put them back out again in May, when the terns come back from their wintering territories along coastlines in Central and South America to nest again.
For this year, Semel said, “It’s rewarding to know that efforts by so many people resulted in a successful nesting season. Hopefully there are enough birds to maintain this population for many more years.”
