Polar bears are one of the most recognized symbols of the north, but they may disappear. Thankfully, we have researchers like Environment Canada scientist, Dr. Nick Lunn, and his team working to find ways to better protect the Polar bear. Right now, Dr. Lunn is way up north in Churchill, Manitoba, studying the effects of climate change on Polar bears. Earth Rangers is thrilled to be invited along for the ride!
Dr. Lunn Reporting from Churchill, Manitoba
Environment Canada has been studying Polar bears near Churchill, Manitoba (click to see map) for over 30 years to learn more about their natural history and the environment in which they live. Here, Polar bear sightings are so prevalent that the area is sometimes referred to as the Polar Bear Capital of the World!
In September, all the sea ice on Hudson Bay has melted and Polar bears are on shore while they wait for the ice to freeze again in November/December. This makes it easier for me to find and catch/release these amazing mammals for my scientific research. Much of the area around Churchill where Polar bears are found is tundra with small clumps of trees scattered around, particularly along the creeks and rivers that flow into Hudson Bay.
I arrived in Churchill on August 30th, 2012 to start this yearâ€™s fieldwork. My plan is to capture 100 Polar bears, take some simple measurements of each animal, collect fat samples to learn what types of seals they are eating, check on their overall health, and attach satellite collars on up to 10 mother Polar bears who have cubs.
Satellite Collars: Movement Patterns and Loss of Sea Ice
The satellite collars will allow me to follow these individuals year-round for up to two years. Although we know that Polar bears spend most of their time traveling and hunting on sea ice, these collars will tell us where they are at all times and will let me know whether some sea ice is better for Polar bears than others.
I donâ€™t have the exact location of any Polar bears yet, only the general area where they are located. To find them, I have to fly in a helicopter and go looking for them. Polar bears this year have been very hard to find, even though their white fur stands out against the dark ground in the summer. When the sea ice melted this summer, it was a little further south than normal so many bears may be spending the summer on the coast of Ontario rather than Manitoba.
Despite getting off to a slow start this year, we captured 45 Polar bears and attached 6 satellite collars. To safely study Polar bears, I put them to sleep for about one hour by using a tranquilizer. Once the tranquilizer wears off, the bears wake up and continue on their way.
I will get the locations of these bears sent to my computer every 4 days. This data shows us how melting sea ice is affecting the amount of time the bears are spending on the ice and their overall movement patterns. Each collar has a â€˜black boxâ€™ that allows the collar to automatically drop off on a day of my choosing. All of the collars that I am putting on this year will drop off on September 1, 2014. I will then be able to pick these up without having to catch the bears again. Using collars that release from the animal automatically is one of the many techniques we use to study these massive mammals.
Measuring Polar Bear Size and Analyzing Diets
When we are working on the bears in the field, we measure the length and width of the bearsâ€™ skulls, their body lengths, and body mass. Weighing a bear is definitely not as easy as it sounds. For some bears, we weigh them in a net that hangs from a special scale. For others, we measure how round they are behind their front legs. Using this number and a special math equation, we get the approximate weight of the bear. This is much easier than putting these huge bears into nets to weight them!
The fat samples we collect are examined using specialized lab equipment to learn more about what seals the bears are eating. Understanding what the bears are eating helps us to see if the loss of sea ice is having an impact on their diet and health.
All bears that I handle are given numbered tags and tattoos that allow me to know who each bear is if I catch them again. No two bears have the same identification number. Polar bears can live up to 30 years, so being able to know each bear I handle allows me to check on how theyâ€™ve grown, how many cubs they may have had, how their movement patterns and diet have changed over time. Collecting a lot of data on individual bears each year really helps us to study the bears in detail.
Polar Bear Summary (August 30 â€“ September 18)
Number of Polar bears captured = 45
Number of satellite collars put on = 6
Number of family groups (mothers and cubs) captured = 6
Number of hours flown in a helicopter = 37.6
An Exciting Partnership
Polar bears live on the sea ice in the winter throughout the circumpolar Arctic, which they use for travel and as a platform to hunt seals. However, the Arctic is warming causing more and more of the sea ice to melt. For animals, such as Polar bears, that are dependent on sea ice to survive, there is great concern for their future. I am very pleased to be partnering with Earth Rangers to study this magnificent animal and to help Bring Back the Wild in Canadaâ€™s North!