Wapusk National Park of Canada
Parks Canada Research and Monitoring Highlights
Ecologist, Wapusk National Park
© Parks Canada
Wapusk News - Volume 6, 2013
Wolverines are good indicators of habitat quality as they require large, contiguous tracts of land. As opportunistic scavengers and predators, they also play a unique role in arctic and subarctic food webs and the health of the wolverine population reflects the health of the system as a whole.
© Parks Canada
Over the past two winters, we have been testing a project that may be useful in estimating the abundance of wolverines in Wapusk NP by collecting samples of their hair. The basic methods are simple: first, set up a series of 6-foot tall posts at regular intervals using a 4" x 4" piece of lumber, or by cutting the lower branches off a tree. Next, wrap the posts in barbed wire, place some fish or an animal carcass at the top of the post for bait, and add some smelly lure to draw the wolverines from far and wide. If all goes well, a wolverine will be attracted by the lure, climb the post to eat the bait, and leave some hairs on the barbed wire in the process. The wolverines aren’t harmed and may repeatedly climb a post over the sampling season, hopefully leaving hairs behind each time. We then check the posts regularly, every two weeks or so, to collect hairs. The hairs are analyzed at a genetics laboratory and individual wolverines are identified using the DNA found in the hairs. Voilà! The result is that we now have a record of the movements of individual wolverines and we can use a mark-recapture statistical formula to estimate the total number of wolverines in the study area.
In 2012, we scheduled time to set up and check the posts using snowmobiles in the spring. Unfortunately, when we checked the posts we didn’t find any wolverine hairs. Not to be discouraged, this year we are back at it, testing out a new combination of bait and lure with the hope of enticing these elusive creatures to climb our posts and leave behind some hairs.
© Parks Canada
Caribou are an important resource for local and Aboriginal hunters. Changes in population numbers of this large herbivore can serve as an indicator of changes in the health of tundra vegetation.
In August 2012, Parks Canada Resource Conservation staff, working with Daryll Hedman and Vicki Trim from Manitoba Conservation and Water Stewardship, conducted an aerial helicopter survey to determine if this would be an effective method to estimate the number of caribou in the Cape Churchill herd. The survey involved flying lines perpendicular to the Hudson Bay coast in the northeast portion of Wapusk NP and counting small groups of caribou as far as 10 km inland. We also followed the coast to look for larger groups and photographed one consisting of 582 caribou! By combining visual counts and photos, we were able to cover a large area in only one day and count both small and large groups efficiently. By flying a test survey in August 2012, we learned how to improve the survey plan, and as a result, are optimistic that in 2013 we will be successful in determining how many caribou make up the entire Cape Churchill herd.
Wapusk NP was created to protect one of the largest known concentrations of polar bear maternity dens in the world. As the earth’s climate changes, polar bears are facing challenges both on the sea ice and on land in western Hudson Bay. By monitoring the number of polar bears with cubs travelling to the sea ice in the spring, we will better understand how their reproductive success is being impacted by these changes.
In Wapusk NP, polar bear mothers and cubs leave tracks in the snow from mid-February to early April, when they travel from the dens where the cubs are born to the sea ice where they feed on seals. By counting these sets of tracks, we hope to be able to estimate the number of polar bears denning in the park, how many cubs they are having, and when they are travelling from their dens to the sea ice. In 2012, we travelled by snowmobile along almost the entire coast of Wapusk NP, counting the number of polar bear tracks we found. This trip was repeated four times, taking 2 to 6 days each time. Wind and snow hindered our progress and we were forced to hunker down in a cabin more than once to wait out a winter storm. Also, the wind and snow made tracking difficult and we found very few tracks -- only eight sets. In winter 2013 we undertook a similar project, but this time by helicopter. Instead of taking days to look for tracks, we were able to search the entire coastline in only 4 hours! Also, from a helicopter, tracks can be spotted over a much larger area. The helicopter track survey has worked very well and on March 1 we found 19 different sets of tracks from polar bear family groups travelling to the sea ice. Return trips on March 7 and March 18 resulted in our finding a few sets of tracks each time. Next year, we plan to begin early in February when we think the first mothers and cubs will start leaving their dens.
Watch future issues of Wapusk News to find out how these new monitoring projects are coming along!