About the Greater Wapusk Ecosystem
Land Acknowledgment Statement
Our research takes place on Treaty Five territory, on the lands of the Cree, Dene, and Inuit peoples and Métis nation. We appreciate the opportunity to conduct research on this land and to learn from, and cooperate with, local community members.
The Greater Wapusk Ecosystem
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Aerial shot of the Greater Wapusk Ecosystem, an ecosystem dominated by wetland habitats. S-T Zhao.
The Greater Wapusk Ecosystem (57.8° N, 93.2° W) is a ~20,000 sq. km (7,700 sq. mi) protected area along the western coastline of Hudson Bay in northeastern Manitoba, Canada. The Greater Wapusk Ecosystem is generally considered to include Wapusk National Park and the Churchill Wildlife Management Area (a protected wildlife area outside the Wapusk National Park boundaries), and is part of the Hudson Bay Lowlands — the world’s second largest boreal wetland ecosystem that stretches from Manitoba eastward through northern Ontario and into the northwest corner of Québec.
The Hudson Bay Lowlands formed after glaciers retreated across the landscape following the end of the last ice age (~11,700 yr ago), leaving behind a remarkably flat landscape pockmarked with small, shallow ponds and lakes. Large swaths of coastal fens, marshes, and peat wetlands lie between the ponds and lakes, with elevated beach ridges in the eastern portion of the Greater Wapusk Ecosystem that run parallel with the Hudson Bay coastline. To the west of the Greater Wapusk Ecosystem lies the town of Churchill, which first gained prominence as a trading outpost during the fur trade era, and remains an important shipping port today.This extraordinary ecosystem lies at the intersection of three major biomes: the boreal forest (taiga), the Arctic tundra, and the marine environment (Hudson Bay). Boreal forest covers most of the western and southern parts of the Greater Wapusk Ecosystem, and is dominated by black and white spruce trees with pine, balsam fir, and tamarack trees interspersed. Where the boreal forest meets the tundra is often referred to as the treeline — a transition zone that is characterized by stunted trees with sparse needle coverage scattered throughout the landscape. Eventually the treeline dwindles, giving way to the vast, open Arctic tundra with isolated tree islands interspersed. Tundra habitats within the Greater Wapusk Ecosystem are characterized by small rolling peat hummocks within the coastal wetlands. The elevated beach ridges in the tundra serve as wildlife highways, where animals can travel with much greater ease during summer compared to the mucky wetlands. The tundra eventually meets the Hudson Bay coastline, giving way to sandy beaches and the marine environment.
Map of the Greater Wapusk Ecosystem in northeastern Manitoba, Canada. The Hudson Bay Lowlands, the largest wetland ecosystem in North America, is pictured in dark blue in the inset map.
Wildlife in the Greater Wapusk Ecosystem
Due to the diversity of environments within the Greater Wapusk Ecosystem, wildlife biodiversity is remarkably high for an Arctic ecosystem. Polar bears are the largest and most prominent species in the Greater Wapusk Ecosystem, which supports the largest known polar bear maternity denning grounds in the world. Polar bears come on land during early summer when the sea ice on Hudson Bay melts. Throughout the summer and fall, the bears loaf and travel along the coastline, gathering in notably high numbers in some areas as they wait for sea ice to form again on the bay. Due to their abundance and the fact that they can be easily observed in the fall, the town of Churchill and surrounding area has become known as the “Polar bear capital of the world”. People travel from all over the world for a chance to observe wild polar bears in the Greater Wapusk Ecosystem. Indeed, the polar bear’s influence and dominating presence was the inspiration for naming the national park: Wapusk is the Cree word for “white bear”.
Polar bear on the Arctic tundra. The Greater Wapusk Ecosystem is home to the world's largest maternal denning grounds, leading the area to be known as the 'polar bear capital of the world.' M. Dobroski
In addition to polar bears, both brown (grizzly) bears and black bears also reside in the Greater Wapusk Ecosystem, albeit at lower densities than polar bears. Black bears are most prevalent in the boreal forest, but they are occasionally spotted out on the Wapusk tundra. Grizzly bears were once thought to have been extirpated from Manitoba, but they have been regularly observed on the tundra since the mid-1990s. The Greater Wapusk Ecosystem is one of the only areas in the world where these three species of bear co-occur. Other prominent carnivores in the Greater Wapusk Ecosystem include gray wolves, wolverines, marten, and ermine (short-tailed weasels). Polar bears, grizzly bears, and wolves are all regularly observed on trail cameras that we have placed out on Arctic fox dens on the tundra. Although these predators are likely attracted to the prey remains that are often strewn about fox dens, they may also occasionally kill fox adults and pups if given the opportunity.
We have installed remote game cameras on numerous Arctic fox dens to record the activity patterns of foxes and other species that visit the dens. Wildlife such as polar bears, caribou, eagles, sandhill cranes, and snowy owls, in addition to wolves like the one seen here, are frequent visitors to fox dens.
The Greater Wapusk Ecosystem is also home to two large ungulates, moose and caribou. Like black bears, moose are most prevalent in the boreal forest and along the treeline. An estimated 3,000 caribou make up the resident Cape Churchill herd, although monitoring efforts are ongoing to provide more consistent estimates of their population size. The Cape Churchill caribou migrate up to 200 km (120 mi) each year between summer and winter, using the elevated beach ridges along the coastline to travel between their ranges. We also regularly observe caribou on the trail cameras placed on dens. Caribou are presumably attracted to the vegetation typically found on fox dens, which is generally more abundant and nutritious than vegetation elsewhere on the tundra.
A caribou cow and her calf on the Wapusk tundra. An estimated ~3,000 caribou make up the Cape Churchill herd. S-T Zhao.
Caribou taking refuge on the tundra during late winter. A. Moizan
At least 200 different bird species have been observed in Wapusk National Park, with likely another 50-100 species that can be found in the Churchill Wildlife Management Area. Most bird species in the Greater Wapusk Ecosystem are only present during the summer breeding months, spending their winters in warmer climates farther south. Breeding migratory waterbirds and shorebirds are ubiquitous on the tundra during summer. The Greater Wapusk Ecosystem is home to three colonies of lesser snow geese, whose populations have increased exponentially over the past several decades. In fact, snow geese are now so abundant in Wapusk that they have damaged large areas of the tundra from overgrazing the vegetation. A long-term project monitoring the snow goose population in Wapusk is ongoing (the Hudson Bay Project ). Other abundant waterbirds include Canada geese, common eiders, Ross’ geese, swans, and the much-revered king eider. Common breeding shorebirds in the area include whimbrels, lesser yellow legs, sandpipers, and American golden plovers. Both Arctic and red foxes rely on migratory waterbirds and shorebirds for summer and early fall food.
A flock of snow geese that have arrived on their summer breeding grounds in the Greater Wapusk Ecosystem. C. Warret Rodrigues
Like Arctic and red foxes, several bird species can be important predators of migratory bird nests and small rodents. Common avian predators in the Greater Wapusk Ecosystem include bald and golden eagles, northern goshawks, peregrine falcons, snowy owls, parasitic and long-tailed jaegers, numerous gull species, ravens, and sandhill cranes. Similar to mammalian predators, most of these avian predators have been captured on our trail cameras at fox dens, and may likewise pose a risk of predation for young, vulnerable foxes. A full list of birds present in Wapusk National Park can be found here.
A shorebird's nest on the tundra. Although generally not as important of a food source for foxes, shorebird eggs and chicks may nonetheless be a sizeable component of fox summer diets. C. Warret Rodrigues.
A sandhill crane foraging in a wetland on the tundra. Sandhill cranes are frequent visitors to fox dens, likely attracted to them by the prey remains scattered across the dens. C. Warret Rodrigues.
Finally, numerous marine mammals (beyond polar bears) are common in our study area along western Hudson Bay. Ringed seals are the most common seal species in the region, and are likely the main prey item that Arctic foxes consume while out on the sea ice in winter. Western Hudson Bay is also home to the largest beluga whale population in the world. An estimated ~60,000 belugas gather annually in summer in western Hudson Bay, in particular within the Churchill, Nelson, and Seal river estuaries. The belugas are thought to use these areas as refugia for calving grounds (females giving birth), as major feeding and breeding areas, and for opportunities to socialize with other belugas. The annual congregation of belugas has become a major tourist attraction for visitors to the area. Other occasional marine mammals in the area include bearded seals, harbor seals, and rarely even killer whales (orcas).
Plant life in the Greater Wapusk Ecosystem
Close-up view of vegetation near an Arctic fox den. C. Warret Rodrigues.
The Churchill region contains a mix of plants of boreal, subarctic and arctic origin. White spruce is the dominant tree on upland sites and black spruce and larch (or tamarack) dominate wetter forests. Forest understories are dominated by ericaceous shrubs (Labrador tea, bilberry and crowberry). Lichens (primarily Cladina, Cetraria and Bryoria species) also make up a major portion of the forest understory (creating lichen woodlands) and non forested areas as well. In non forested upland areas the most dominant non graminoid plants are white mountain avens and purple saxifrage. Fens are dominated by sedges with water sedge being the most common.
Three-toothed saxifrage, a relatively common plant in the Greater Wapusk Ecosystem commonly found in rocky areas. C. Warret Rodrigues.
Crowberry plant, often found in the boreal forest sections of the Greater Wapusk Ecosystem. C. Warret Rodrigues.
Plant community types are driven by climate (distance to the coast) and drainage. Coastal areas contain more Arctic species, with tree cover being reduced to scattered tree islands. Wetlands dominate the region, with the wettest areas being dominated by sedge fens. Progressively drier areas contain shrub sedge fens, sphagnum bogs and larch fens. The wetlands grade into lichen peat plateaus and spruce dominated woodlands. The driest areas, on ancient beach ridges and moraines, contain heaths dominated by ericeacous species.