Why southwestern Ontario is currently home to thousands of sandhill cranes

The birds usually stop by before heading south for the winter — so what’s keeping them here? TVO.org speaks with Bird Studies Canada’s Stuart Mackenzie about climate change and crane-watching
By Mary Baxter - Published on Feb 26, 2020
In the late 19th and early 20th centuries, sandhill cranes were hunted nearly to extinction, but they’ve since made a comeback. (Mary Baxter)

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On a mid-February morning at Big Creek National Wildlife Area, which encompasses 771 hectares on the north shores of Lake Erie, eastern sandhill cranes patrol the icy surface of a marsh. The large grey birds with red-splashed foreheads take off, swooping one way, then another, and the air fills with squeaky chatter. They land in a field and scratch for grain.

Sandhill cranes are no strangers to the area, which sits at the base of the Long Point peninsula, a 40-kilometre sand spit that's a little more than an hour’s drive from London. It’s one of Ontario’s most important staging areas for bird migration. What’s unusual, though, is that they’re here now. Typically, the migrating birds visit briefly in the fall and early winter before continuing toward the American Midwest and, sometimes, as far south as Florida. But, this year, thousands have remained — there are roughly 4,300 today, according to a Canadian Wildlife Service count.

In the late 19th and early 20th centuries, sandhill cranes were hunted nearly to extinction. But they’ve been making a slow and steady comeback, according to Chris Sharp, a population biologist with CWS. “What we’re seeing is a recolonization of historical breeding areas,” he says. “On top of that, sandhill cranes are quite opportunistic feeders, and they've really taken a liking to agricultural crops.”

That’s caused some groups, such as the Ontario Soil and Crop Association, a non-profit farm organization, to call for a crane hunt in the province. CWS introduced a multi-year tracking study in the fall of 2019 to learn more about the birds’ behaviour, attaching GPS transmitters to 24 cranes. “The end goal of this project is to learn about how cranes are using the agricultural landscape,” Sharp says. “And, if we can, [provide] better guidance to producers.”

Stuart Mackenzie, director of migration ecology at Bird Studies Canada, a national non-profit, appreciates what the cranes bring to Long Point. “The swans have been an attraction in late winter/early spring for visitors to Long Point and Norfolk County for decades, as have spring waterfowl. The cranes add a new twist to that,” he says. “It's one more thing to enjoy and to look at.”

TVO.org spoke with Mackenzie about the growing population, its effect on ecosystems, and how to get the most out of crane-watching.

TVO.org: How far north are the cranes coming from?

Stuart Mackenzie: Probably tundra as far north as northeastern Quebec and Labrador, I suspect, and then northern Ontario as well.

There are large staging areas on Manitoulin Island and in the Temiskaming area. They'll stage there as they move south to areas like Long Point, which is another staging area.

cranes in a marsh
The Ontario Soil and Crop Association, a non-profit farm organization, has called for a crane hunt in the province. (Mary Baxter)

Have you noticed changes in the crane population over time?

I've been here long enough to notice a slow and steady increase over the past 20 years. And then, over the past decade, it's become much more prominent. Even just going back five years, we may have had peak counts around 1,000, and then, this year, we're in the 5,000 to 6,000.

Why are they staying?

Staging areas, when they can support birds all winter, do become overwintering sites. That's the case of what's happening at Long Point right now.

But it depends on the year. If we had a severe winter, most of these birds would have carried on south because what they feed on in the winter is mostly waste grain. They still forage in the wetlands and eat worms and whatever they can get their hands on, but a lot of them are being sustained by waste grain — primarily, corn in the fields.

And that is a little bit by design. A lot of hunt clubs in the area and Ducks Unlimited plant grain and will, at harvest, purposely leave some behind for the waterfowl. Sometimes they'll leave standing grain so that there's a source of it throughout the winter.

Do you know why this year’s population is breaking records?

We're not exactly too sure if that's just a shift in habits that allowed us to detect them. It's probably a little bit of that and, also, an increase in a population that wasn't here before.

Sandhill cranes are now one of the most numerous overwintering birds in terms of numbers. There are lots of numbers of other passerines — your songbirds and finches — but they're more dispersed on the landscape. You notice the cranes because they all stick together.

Has the large crane population this year affected the local ecosystem?

That's hard to tell.

We think they're eating grain. So they're removing grain from the landscape, which would be available for ducks and other waterfowl and geese. But they all tend to coexist. There's a lot of grain to go around.

There are increasing local populations of cranes as well. Historically, a number of decades ago, there might have only been one or two pairs of sandhill cranes in the Long Point marshes; now there's easily a dozen different pairs.

That’s similar in many wetlands across Ontario where cranes are now occupying spaces that they hadn't previously. Within wetlands they certainly eat their fair share of frogs and snakes, but they eat anything that moves. So they may be impacting some species at risk in the case of snakes or frogs. But wetlands are robust, and, if there wasn't enough food in there for them, they wouldn't be there.

How are people responding to them?

Most of the locals don't necessarily pay attention. The connected ones do and would have noticed them and enjoyed them. And then there's probably an equal amount of population that is annoyed by the people parked on the side of the road and don't want the attention or traffic that it brings to the county. So, it's a trade-off that everybody has to deal with.

Will the cranes become as populous year-round in southern Ontario as Canada geese?

They won't become as ubiquitous as geese. It's a little bit of a climate-change issue where our climate here is becoming just more amenable for overwintering populations of large birds like waterfowl and ducks.

It's also a human thing. It's how we manage our urban spaces, which are prone to having open water in them, whether it's sewage treatment or just the heat of a city can keep many rivers and streams open. And many of the birds, both for food but also for sanctuary and safety, require open water to be able to rest and to be away from predators.

Any tips on what to bring or do when watching the cranes?

Bring warm clothes — there's always wind or something like that — binoculars or a telescope, and a camera.

If you're pulled over, just be sure to be pulled over and have your four-ways on.

You should also bring your patience and your silence. Just let the birds come to you. Often people will go birding and expect the nature shows or what you see in photographs, not knowing that it takes those photographers thousands of hours to get that shot.

This interview has been condensed and edited for length and clarity.

This is one in a series of stories about issues affecting southwestern Ontario. It's brought to you with the assistance of faculty and students from Western University’s Faculty of Information and Media Studies.

Ontario Hubs are made possible by the Barry and Laurie Green Family Charitable Trust & Goldie Feldman.

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