The common tern is a bird best known for its graceful flight and dramatic dives. Over the past 50 years, its best nesting habitat in the Great Lakes has been taken over by more aggressive birds, like gulls, cormorants, and osprey. Today, common terns are a threatened species in New York and Minnesota, and monitored carefully in other states. A couple years ago, a biologist and some volunteers used gravel and navigational buoys on the St. Lawrence River to create artificial nesting habitats for the terns. The Great Lakes Radio Consortium’s David Sommerstein reports on the experiment’s progress:
The Common Tern is a bird best known for its graceful flight and dramatic dives. Over the
past 50 years, its best nesting habitat in the Great Lakes has been taken over by more
aggressive birds, like gulls, cormorants, and osprey. Today, common terns are a
threatened species in New York and Minnesota, and monitored carefully in other states. A
couple years ago, a biologist and some volunteers used gravel and navigational buoys on
the St. Lawrence River to create artificial nesting habitats for the terns. The Great Lakes
Radio Consortium’s David Sommerstein reports on the experiment’s progress:
The St. Lawrence isn’t just a river – it’s a seaway – an aquatic interstate for ocean freighters rumbling into the Great Lakes. So it’s not strange.
I’m in a boat floating just upstream from one of the river’s highway signs, a seaway
We’re not talking about a plastic buoy – it’s a fixed concrete column rising 8 feet above the
water. Its platform is big enough that you can walk around on it. On top, a tall steel tower holds a red light and signs that serve as channel markers for the seaway traffic. But for the conservationists I’m tagging along with, this is bird habitat. We sit in silence and listen to the call of the Common Tern.
(tern squawking in the clear)
Dozens of small white birds with pointy wings and black caps swoop above our heads.
They soar, suspended, then suddenly dive into the water. Their orange beaks snap at
minnows just below the surface, then they shoot back up into the air.
This particular colony was formerly the largest and most productive Common Tern
colony on the entire lower Great Lakes.
Biologist Lee Harper is known as “the tern guy” in this part of the Great Lakes. He’s
tagged thousands of them and recorded them as far away as Brazil. He documented the
common tern’s dramatic decline over the past twenty years. Gull and osprey populations
exploded, displacing the more sensitive terns from their nesting sites. But today Harper
peers through binoculars and grins.
“The terns we’re seeing here today represent the first nests on this site in almost ten
Terns don’t need much to nest, just a dry, isolated spot near water. Harper noticed the
refugee terns were retreating to navigation markers like this one. They’d lay eggs on its
concrete platform. The problem was the eggs would roll around and the birds would abandon
them. So Harper enlisted volunteers to lug 5 tons of gravel out here. They spread it on the
platform so the terns would lay their eggs on top of the gravel and the eggs wouldn’t roll.
Suzie Wood was among them.
“The first time I saw it, it was a piece of concrete and I frankly thought that Lee was a
little bit cracked when I heard about it.”
That was two summers ago. Today’s the first day the volunteers have returned. They’re
going to count nests and eggs to see how the gravel is working.
(motor sound, then clanking and action sound as we tie up)
We inch the boat up to the marker and huddle under the canvas top in case the birds dive-
bomb our approach. Then we tie up to an iron ladder that leads up to the concrete
platform. One by one, we climb the ladder and peer over the platform’s rim.
“Wow, this is a beautiful nest right here.”
Lee Harper is right behind and he’s beaming.
“After ten years of no terns here, this is really a wonderful sound!”
Almost invisible amongst the gravel and weeds are clusters of brown spotted eggs. We
walk on tip toe, look before every step, careful not to crush a nest. Harper works quickly
to minimize the disturbance. He calls out the number of eggs he sees. A volunteer takes
notes on a clipboard.
Harper was here two weeks ago and counted 18 nests. Today there are 40 common tern
nests. Volunteer David Duff is impressed.
“It was just such a simple thing to do. I mean, a hundred twenty dollars worth of gravel
and a two or three hours and half a dozen people helping with five gallon buckets of gravel
and I think we have a victory, at least a preliminary victory.”
The gravel nests are starting to catch on. The St. Lawrence Seaway Development
Corporation is spreading gravel on navigation markers all along the Seaway. Groups in
Michigan are planning similar restoration efforts, using dredging spoils from the St. Mary’s
River. They’re man-made solutions, but ones that just might restore the Common Tern
population to health in the Great Lakes.
For the Great Lakes Radio Consortium, I’m David Sommerstein.