American avocet (Photo by C. Artuso)
Shorebirds are a diverse group of migratory birds, a few species of which have some of the longest migration distances in the feathered world.
This group of birds is strongly associated with shallow water habitats, such as those found on beaches or shorelines of lakes, shallow wetlands and in flooded fields or grasslands, where they forage for food in the mud and sand.
The migratory route that passes through the Prairies is sometimes referred to as the central flyway. A handful of the species that move through Manitoba stay and breed, raising their young before returning south for the winter. Others only stop temporarily for food and rest on their way north or south.
Shorebird populations are declining
A 2016 State of North American Birds report showed a 70 per cent decline in shorebird populations since the early 1970s. Causes of that decline range from habitat loss in breeding and wintering areas and along migratory pathways, changes in predation pressure, pollution, changes in food availability, changing climate conditions and being repeatedly disturbed while resting and feeding.
International shorebird surveys
Over the past couple of years, numerous partners including the Nature Conservancy of Canada (NCC), Bird Studies Canada, Manitoba Important Bird Areas (IBA) Program, the Souris River Watershed District, and Environment and Climate Change Canada have worked to develop monitoring programs to learn more about shorebird populations, migration, distribution and their trends in southwest Manitoba. This included training volunteers on shorebird identification in partnership with Manomet and establishing nine international shorebird survey routes in southwestern Manitoba — a standardized monitoring protocol implemented across the world to collect consistent, comparable information on shorebird trends.
2019 international shorebird survey observations
American avocet (Photo by C. Artuso)
Volunteers took on nine survey routes in the Oak Lake and Plum Lakes and Whitewater Lake Important Bird Areas.
- Twenty-four species of shorebirds were recorded across all the routes.
- The most abundant shorebird was the American avocet with 1441 observations.
- Stilt sandpiper, short-billed dowitcher, greater yellowlegs and lesser yellowlegs had over 500 observations each.
- Two shorebird species listed as special concern under Canada’s Species at Risk Act were observed: red-necked phalarope (80 observations) and buff-breasted sandpiper (1 observation).
- 205 observations were made of “peeps.” These are not the popular Easter candy, but a term birdwatchers use for species of shorebirds with a very small-body size that are difficult to identify from a distance without a powerful birding scope.
- During the surveys, 89 species of other birds of note were also documented.
- The most commonly observed bird throughout the year was Franklin's gull with 5,849 observations!
Wildlife tracking towers
Motus Towers (Photo by NCC)
NCC's Manitoba Region, as part of the Motus Wildlife Tracking System, has installed three towers in southwestern Manitoba: two near Oak Lake and a third at Whitewater Lake.
Antennae atop the towers collects signals from radio transmitters that have been attached to birds and large insects. When a shorebird with a transmitter flies within 20 kilometres of the tower, information is captured. The data is then downloaded from the towers and shared with other researchers and organizations who are part of the Motus wildlife tracking network.
The data from these and other towers across the country and around the world provides key information on which species are travelling through an area, where they came from, what routes they are taking and at what times. This information helps inform which areas are of most importance to these birds along their migration route in order to implement conservation strategies.
Stories from the field
After a few technical glitches, NCC’s towers picked up six detections in 2019 from three species, only one shorebird was recorded — a semipalmated sandpiper. This small bird was tagged at Rockefeller Wildlife Refuge, Louisiana, then travelled to Canada to breed. On its southern migration it stopped at Whitewater Lake for four days, before arriving at Chesapeake Bay in Virginia a week later! A bank wwallow and a Swainson’s thrush were also were detected by the towers, and though not shorebirds, the location information provided by the towers will provide important information for the researcher working on these species. Read about the research projects these three birds are part of below.
Semipalmated Sandpiper Stopover Project, Tulane University
Semipalated sandpiper (Photo by Alan Kneidel)
“Semipalmated sandpipers are a near threatened shorebird that spend the winter in the tropics and breed in the Arctic. In my project, we are investigating how coastal habitat in Louisiana affect the spring migration of semipalmated sandpipers (Calidris pusilla). We are using the Motus network to understand how much time the birds are spending on the Gulf Coast, and how different habitat types influence migratory behavior. Additionally, using the Motus network also allows us to track the birds during migration through North America. Motus towers such as those in Manitoba connect wetlands that these shorebirds are using throughout the continent, which was previously unknown.” - John Herbert
B.C Interior Thrushes Project, Canadian Wildlife Service & Texas A&M University
Swainson's Thrush (Photo by Robert Alvo)
“We are interested in the role differences in seasonal migration play in speciation and in this project we are using a hybrid zone between Swainson's thrushes to study this topic. Coastal and inland subspecies of thrushes migrate along different routes (one hugging the west coast to winter in Mexico and Central America) and the other migrating over the Rockies (through Manitoba!) to winter in South America. The birds captured by NCC towers were fitted with tags at the center of the hybrid zone. We are testing the hypothesis that hybrids take intermediate routes between pure forms, as they have a mix of the two pure genomes. Your birds are likely pure inland birds living in the hybrid zone; we will use genomic tools to validate this idea in them coming year.” - Kira Delmore
Saskatchewan Passerine Ecology Project, Environment and Climate Change Canada
Tagged Bank Swallow (Photo by Ana Diaz)
“We tagged a bank swallow just south of Saskatoon and we think it took one day to get southern Manitoba. The project is investigating post-breeding survival of adult and juvenile bank and barn swallows in agricultural landscapes in Saskatchewan using a small network of Motus towers. We were hoping that the birds would be picked up by the Motus network during their migration and passing by a tower in Manitoba is like finding a needle in a haystack, so we’re glad NCC put up those towers!” - Kevin Kardynal
Shorebird Birders (Photo by NCC)
International shorebird surveys will continue this year at the Oak Lake and Whitewater Lake Sites, and new sites are being established in central Manitoba by the Manitoba IBA Program this spring. Contact NCC or the Manitoba IBA Program to get involved:
Manitoba Important Birds Area Program
Nature Conservancy of Canada - Manitoba Region