“It’s a threatened species in Canada.”
Just off the steep cliff faces of Niagara Shores Park, at almost all hours during spring, summer and fall, a captivating aerobatics show is on display.
A colony of small birds dances its way to a fresh meal for its young fledglings, which nest metres away in the soft sand and clay of the park’s embankment.
The birds, appropriately, are called bank swallows, and build their burrows into sandy vertical faces along lakes and rivers.
The story of the bank swallow might not have a happy ending, though — as Ontario has lost more than 90 per cent of its bank swallow population since 1972, thanks to shoreline protection and lakefront development. They are one of Ontario’s most threatened bird species.
The Lake Report spoke with Bird Studies Canada experts Liz Purves and Megan Hiebert to find out a bit more about the birds and why the populations are in decline, and to see if it is related to eroding shorelines.
Purves and Hiebert spend their summers doing hands-on research with bank swallows along the coast of Lake Erie.
They literally count bank swallow burrows as part of their research and are acknowledged experts on the birds — which are often confused with other types of swallows, like barn swallows and cliffside swallows.
Bank swallows are aerial insectivores, which means they eat insects while in flight.
The spectacle is fascinating to watch, as the tiny birds swoop through the sky, performing aerial tricks as they hunt. But this means they need to nest in places where food is abundant. Lakes and riverbeds provide ideal habitats, with plenty of insects hovering above the water.
The birds come all the way from South America to spend the summer in Niagara-on-the-Lake. Tagged birds have been recaptured and documented as far away as Peru.
Many Niagara residents are concerned the erosion is destroying the habitat for the birds, but, in fact, the opposite is true, experts say. Near-vertical cliffs are crucial to the bank swallows’ habitat and nesting, but those steep embankments are only formed via erosion. Building a breakwater barrier near their nesting area could destroy their habitat.
On the other hand, erosion can be deadly to the birds and their habitats, if it occurs aggressively at the wrong time of the year.
“Erosion is tricky because it has to happen at the right time for bank swallows,” says Hiebert. “It has to happen before they start laying eggs, before they get into nest building, and definitely before they have babies. If it happens when they have babies, well, that kind of sucks.”
“I can’t say for sure it’s because of high water levels, but it kind of looks that way,” she says.
“You could see places where there had been recent erosion, and it probably just wiped out a whole ton of nests, which is unfortunate.”
Bank swallows are finicky, in that all tests so far have shown they won’t use artificial nests, or nest in an artificial environment. They want sandy, soft banks, close to the water. And there isn’t much that can substitute for that. Near the water, bugs are flying, and food is prevalent.
“The artificial habitiats that I’ve heard of haven’t worked out spectacularly,” says Hiebert. “I know that they have been trying different mixes of sand and stuff, to try and entice the bank swallows to go in it, and they just wouldn’t use it. They prefer a pile of dirt.”
As crashing waves continue to erode Niagara’s shoreline by an average of one metre per year, the challenge of preserving coastal land comes face-to-face with preservation efforts for the bank swallow.
Niagara Shores Park is home to a significant population of the tiny, migratory bird that makes its burrows in embankments along lakefronts and riverbeds.
Amid growing concerns about the preservation of bank swallow habitat in Niagara-on-the-Lake, The Lake Report spoke at length with Purves and Hiebert about the life cycle of the birds and the causes leading to the decline of the species in the province.
With populations having dropped more than 92 per cent in Ontario since 1970, combined with the ongoing loss of shoreline, there is a sense of urgency in finding out the best ways to protect the swallows, while preserving coastal land.
Purves and Hiebert, who are researching bank swallow populations and patterns in Ontario, say the birds will only nest on cliffs like those in Niagara Shores.
Part of the problem is that without shoreline erosion, which creates steep banks, the birds wouldn’t have places to burrow. As more and more shoreline protection occurs along the Great Lakes, it stops the natural creation of the birds’ habitat.
Steep banks are critical, say Purves and Hiebert. The angle prevents grass and plants from growing in the side of the cliff. If the grass were to grow, the birds, which use their tiny beaks to build their burrows, wouldn’t be able to make their nests. Though they’re powerful enough to dig holes up to one metre into the soft sand, they aren’t able to burrow into thick roots.
The steep angle also helps the birds keep out of the way of natural predators, like racoons and skunks, which are prevalent in Niagara-on-the-Lake.
In the case of the bank swallow population, finding a way to prevent eroding shoreline, while preserving natural bank swallow habitat, is crucial to the success of preservation.
Researchers have tried to create artificial habitats for the birds, but they haven’t been successful.
“The birds don’t like it,” says Purves.
There is no specific guideline for how to repair a shoreline while mitigating damage to bank swallow habitat, Purves and Hiebert say.
And federal laws restrict the further destruction of bank swallow habitats, so without a functional plan for shoreline protection that also preserves swallow burrows, a solution seems unlikely.