Canada provides crucial breeding habitat to millions of migratory birds every year. Thanks to new methods of tracking and counting, we are learning more and more about their extraordinary lives — and the many challenges they face here and abroad
THE STORY OF BIRDS IN CANADA — and their increasingly apparent, if uneven, decline — is a story of multitudes in motion: many hundreds of distinctive species, several billion restive individuals, many of which spend just a few months each year within our borders before they and their new offspring depart for wintering grounds in either the U.S., Mexico or Central and South America.
“You really have to consider the full life cycle of those species to understand their true reality,” says Bruno Drolet, a senior biologist with Environment and Climate Change Canada, in Quebec City.
For most Canadians, even those who are noticing birds more due to pandemic lockdowns and at-home isolation, anything other than a glimpse of that life cycle may seem out of reach.
But as it turns out, it’s not that much easier to attain for committed amateur birders or even for professional biologists.
When Environment and Climate Change Canada published the most recent The State of Canada’s Birds report in 2019, for example, with nearly 50 years of population trend data for more than 400 species, the project steering committee needed to tap more than a dozen different long-term monitoring programs.
That report contained some stark details: while many species of waterfowl and birds of prey have increased in number since 1970, the populations of more than half of Canada’s birds, particularly grassland birds, aerial insectivores and shorebirds, have plummeted by 40 to 60 per cent, on average.
To get this information, the authors drew on two long-running national and continental surveys — the Christmas Bird Count and the North American Breeding Bird Survey — that depend on thousands of volunteer citizen scientists to gather the field data. They also drew on many lesser-known counts that focus on specific regions, habitats or types of birds. Done by professionals with the Canadian Wildlife Service and the United States Fish and Wildlife Service as well as other groups, these counts require planes, helicopters and often arduous, challenging and sometimes dangerous fieldwork. Even after all that, the report comes with a big asterisk: nearly one-quarter of Canada’s bird species are not yet well monitored.
The point is not to say that report’s findings aren’t hugely significant. Rather, it’s to underscore the enormity and incomplete nature of the task — and to shine a spotlight on another ascendant Canadian program that combines migratory bird banding, data collection and research with creative public engagement and education about birds and conservation: the Canadian Migration Monitoring Network.
This network of nearly 30 independent bird observatories strung across the country from the Bay of Fundy to the tip of Vancouver Island was founded in 1998 as a cooperative venture between the stations, the non-profit conservation organization Birds Canada and the Canadian Wildlife Service (a branch of Environment and Climate Change Canada). It is now coming into its own in important ways.
Most of its member observatories are small non-profits with modest budgets, few staff and lots of committed volunteers. While important locally, what makes them nationally significant — and an example globally — is that belonging to the network requires adhering to standardized data gathering protocols. They submit that data to the network, where it is compiled and analyzed, producing a Canada-wide dataset of trends and other insights for use by other researchers and policy-makers. Doing that turns “these little Davids into a Goliath,” says Stuart Mackenzie, migration program manager at Birds Canada and a member of the network’s 12-person steering committee.
It also puts another ally in the corner for Canada’s birds when there has never been a greater need.
AT 42 SQUARE KILOMETRES, PELEE ISLAND IS the largest island in Lake Erie. But it is probably best known for two things: being the southernmost populated point in the country, as well as a resting and refuelling mecca for hundreds of species of birds travelling to and from Canada via two of the continent’s great migratory bird routes, the Atlantic and Mississippi flyways.
Those birds also attract many birders and tourists. Springsong Weekend is a highlight for both, traditionally held on Mother’s Day weekend in May and hosted by author and bird lover Margaret Atwood. What attendees might not realize is that at the same time Atwood helped launch the event in 2002, she was co-founding the Pelee Island Bird Observatory, along with her longtime partner, the late Graeme Gibson, and Gibson’s son, Graeme the younger, who was the observatory’s managing director until 2017.
Before the Pelee Island Bird Observatory, the younger Gibson first trained as a field ornithologist up the lake at the Long Point Bird Observatory. Founded in 1960, this bird observatory is the oldest in the Americas and the largest in the Canadian Migration Monitoring Network. Many of the monitoring and sampling methodologies used at the network stations were developed there.
Also, like Gibson, the founders of many other Canadian observatories first trained at Long Point. Even Birds Canada, which now manages the Long Point Bird Observatory as well as the Thunder Cape Bird Observatory on Lake Superior and also serves as the network’s administrative home — collecting, analyzing and archiving its stations’ migration monitoring data and coordinating network-wide research — is based in nearby Port Rowan and owes its existence to the observatory.
When the Canadian Migration Monitoring Network was formed, it consisted of a dozen migration monitoring stations. By the time the Pelee Island Bird Observatory officially joined in 2005, it had more than 20, and it has grown gradually since. Most are either at coastal sites or next to inland lakes where birds tend to congregate in large numbers during migration, locations also often designated as Important Bird Areas, a globally recognized conservation concept. A few observatories are in big cities, like Victoria, Toronto, Calgary and Montreal, while others are more remote. Many are also located in, and sometimes affiliated with, parks or protected wildlife areas.
In every case, nature abounds. In the Long Point Bird Observatory’s long history, for example, it has recorded more than 400 species of birds. In a different extreme, the Observatoire d’oiseaux de Tadoussac, on the north shore of the St. Lawrence River estuary east of Quebec City, is renowned for the occasional flood of warblers and other returning spring migrants. These are thought to occur when the birds have been blown off course out over the water and return to shore before continuing north. One day in 2018, birders there counted an estimated 500,000 to 700,000 birds, the largest single daily count ever recorded.
Aside from its illustrious literary pedigree, the Pelee Island Bird Observatory’s program roster reflects activities typical at many of the Canadian Migration Monitoring Network observatories (prior to COVID-19, which has disrupted every station’s activities). At its heart is the daily monitoring through the spring and fall migration seasons. This involves both a 90-minute census walk, counting every bird that’s present, followed by the tallying and banding of birds captured in mist nets near a banding station at the island’s south end. According to executive director Suzanne Friemann, field staff also conduct a resident breeding bird census, summertime marsh monitoring and northern saw-whet owl migration monitoring in the fall. The observatory also runs a year- round education program — now a staple at most observatories — held off-site in Windsor, where there is a large enough audience to support it.
Elsewhere, programs and activities vary depending on resources and location.
Rocky Point Bird Observatory, for example, with two station locations on the southern tip of Vancouver Island, conducts passerine (i.e., perching or songbird) migration monitoring only in the fall. But its other activities include a year-round sea-watch program that gathers data on area seabirds and a hummingbird banding project at remote locations in B.C.’s southern interior. Like a number of network observatories, it also collects data for a North America-wide project tracking the health and productivity of local breeding birds, called MAPS.
Launched in 1994, Rocky Point joined the Canadian Migration Monitoring Network in 2001. “We’ve kept building and building,” says Ann Nightingale, a longtime board member.
That building process has included a lot of education programming and public outreach. Not only is it important for fundraising, but Nightingale says it’s central to the mission of saving birds. “Big actions to protect the environment tend to come at the governmental level. And our best way to influence government to make better decisions for birds is to make people care about birds.”
Growth is a constant theme across the network, according to Patti Campsall, executive director of the Lesser Slave Lake Bird Observatory. Located in a provincial park on the eastern shore of Lesser Slave Lake northwest of Edmonton, its original banding station underwent a major expansion in 2006 when it partnered with Alberta Parks on an education and research centre that doubles as a visitor centre for the park.
Dubbed the Boreal Centre for Bird Conservation, the centre is used by the observatory to run a year-round education program for school kids in the area and other special events. Simultaneously, it has fostered expansion of the observatory’s research field station activities to include collaborative projects with universities across North America. In the most recent of those, researchers from Columbia University in New York teamed with the observatory’s field staff to capture American robins during spring migration, outfit them with tiny GPS units and then release them back to the wild. Those devices linked directly to NASA satellites, enabling the researchers to track the birds’ habitat use en route to their final breeding destinations.
“What’s happened with our station is a trend that I’ve seen happening to a lot of the stations,” says Campsall, who also sits on the Canadian Migration Monitoring Network steering committee. “There’s a real evolution from the core banding programs.”
FROM A NETWORK STANDPOINT, HOWEVER, the observatories’ core banding and census migration monitoring activities are still key — and point the way to a future where the Canadian Migration Monitoring Network observatories and their data might have the biggest scientific impact in helping inform bird conservation efforts in Canada and through- out the western hemisphere.
Recall that asterisk in The State of Canada’s Birds report and the nearly 25 per cent of bird species that are not yet well monitored. According to the report, these include a range of species, such as Arctic-nesting birds, pelagic seabirds, sea ducks, certain owls and “cryptic or very rare birds.”
Another known unknown, to borrow a phrase, is the exact status of scores of birds that breed every year in the boreal — the massive band of relatively undisturbed forest that runs through central and northern Canada from Newfoundland to the Yukon. Many are the songbirds that winter in Central and South America.
The main issue from a conventional monitoring perspective is that the North American Breeding Bird Survey methodology — the gold standard in field data collection — relies on roadside surveys. Yet there are no roads beyond the southern fringes of the boreal and, hence, no surveys. As Erica Dunn, a now retired Canadian Wildlife Service research scientist who co-chairs the Canadian Migration Monitoring Network’s steering committee and also heads its science subcommittee, explains, this means any trends for boreal breeding species based on data from the Breeding Bird Survey “may not be representative of the whole region.”
The network’s founders recognized this problem when the network was first proposed. As a result, while observatories may see a lot of birds, the timing and structure of their banding and census work is chiefly designed to target these neotropical migrants after they leave or are returning to the boreal — to obtain accurate counts of those birds passing through the stations and then plug that data in models to come up with overall population estimates.
A big part of what has taken place in the network’s first 20 years of operation has been expanding that database (in terms of both time and geographical coverage) and then attempting to validate its potential to serve as an accurate proxy for actual field surveys in the boreal. As a control, researchers started by comparing their long-term population indexes for migratory birds that breed in southern Canada with results in the North American Breeding Bird Survey. A high correlation would affirm the validity of the network data and modelling and, for the most part, that’s what was found.
“Results indicated that migration monitoring is indeed measuring a similar population signal to BBS for species breeding primarily in the south, particularly in spring,” wrote the authors of the network’s Ten-Year Report on Monitoring Landbird Population Change, published in 2008. “However, this relationship breaks down for species breeding primarily north of BBS coverage. By inference, these results further support the notion that migration monitoring can be used to effectively monitor the status of boreal/northern breeding birds where BBS coverage is weak.”
That’s only step one, however. Observatory counts alone may produce trends for specific points in the migration, but they don’t indicate where those birds originated or where they might end up on their return.
“When a bird hits a net at a banding station, you have no idea where it’s coming from,” says Keith Hobson, a professor of biology at Western University in London, Ont., and a principal investigator with that school’s Advanced Facility for Avian Research.
To solve that puzzle, scientists like Hobson look to basic chemistry. It turns out that patterns in stable hydrogen isotopes in rainfall vary by location. When that water enters the food web, those signatures are imprinted in the feathers of birds (and other animal tissues) that develop there. “Because most birds in North America moult their feathers on the breeding grounds before they migrate, those feathers carry a signal of where they came from,” says Hobson.
Several years ago, working with feather samples collected (harmlessly) from birds captured at network banding stations during spring migration, Hobson and others were able to determine roughly where those birds came from. Over time, they’ve used that data to create maps that show the “catchment areas” for different species of birds banded at each observatory.
“We’ve created these origin maps for about 15 species now,” Hobson says. “It sounds pretty simple: where do you come from? But just knowing and describing that … opens up a huge number of possibilities. I think the scientific worth of these stations has really increased because of that.”
IS THAT INFORMATION ACCURATE ENOUGH that Environment and Climate Change Canada might begin to incorporate the network’s population trend data when it next assesses the conservation status of those species, either individually or in the next report on the state of Canada’s birds?
That door seems to be open — and a new pilot study in which the federal department has partnered with the network’s science committee, focused on the blackpoll warbler, may seal the deal.
The blackpoll is a migratory songbird that breeds in spring and summer throughout the boreal and winters in South America — and its southbound route is particularly epic. Blackpolls, which weigh less than a loonie, begin the trip by flying east, out over the Atlantic Ocean, then travel nonstop for several days before landing either in the Caribbean Islands or the northeastern coast of South America. The 2,000-to-2,500-kilometre journey is the longest recorded overwater flight of any songbird.
The relevant measurements in this study, however, have to do with their population levels in the boreal. Based on the Breeding Bird Survey data, their situation is dire, with their population having plummeted 83.8 per cent between 1970 and 2016. Yet data gathered by network observatories since the 1990s indicates relatively healthy and stable blackpoll populations in western and central Canada, with a decline only in the East.
The goal of the joint study is “to understand the discrepancy,” says Environment and Climate Change Canada’s Bruno Drolet, who is also a member of the network steering committee and who ran the observatory at Tadoussac for three years in the early 2000s.
Based on the Breeding Bird Survey reports, Drolet says the blackpoll is a candidate for assessment and potential listing by the Committee on the Status of Endangered Wildlife in Canada. “One of the pitfalls we want to avoid at all costs is to declare a bird as a species at risk, where in fact it’s not at risk at all, because of bad data,” he explains.
To be clear, his department isn’t looking solely at the network’s data only to address data gaps involving boreal birds. Under the auspices of a Canadian Wildlife Service boreal monitoring strategy, work is now underway on a lengthy, elaborate and expensive plan to deploy a boreal monitoring ground survey to count birds during the breeding season. In a paper published last year in the journal Plos One, the department laid out what it believes to be the most cost-effective, statistically accurate sampling methodology to follow. Now, Drolet says he and his colleagues in other regions are working on its implementation.
“The challenge is titanic. And the resources are limited. So, it might take 20 years to cover the entire boreal,” he says — even longer to build up a time series to assess trends.
According to Dunn, the magnitude of that task underscores the potential value that the network’s migration monitoring surveys can bring to the table. She’s hopeful the early progress they’re making in the blackpoll warbler pilot will soon result in Environment and Climate Change Canada looking more closely at the data that Hobson and others have so far compiled for another dozen or more boreal breeding migrants.
“This is really an exciting development for the network,” says Dunn. “This is really what we’ve been working for, working towards, for 20 years. And we’re finally in a position to get there.”
This article was originally published in the March-April 2021 issue of Canadian Wildlife magazine.