Each year, the Polar Bears International Bear Tracker follows a subset of GPS-collared female polar bears in Hudson Bay. By monitoring these movement data, scientists can determine when and how polar bears use their sea ice home, helping us better understand what the species needs to survive and thrive.
Spring is the time of year when polar bear moms emerge from their dens with their cubs to find their first meal after eight long months without food. It's the feasting season for polar bears, also known as hyperphagia, with young seal pups making for easy, blubbery prey. Below are snapshots of what a few bears on our Polar Bear Tracker have been up to.
Eight-year-old Ares and her yearling are true Western Hudson Bay polar bears. Since October, they have remained in the midwestern portion of the bay, not travelling very far north or very far south, and definitely not far east. This is probably a good strategy for a relatively young mom who has led her yearling over 1,511 km in about five months: sticking to what you know may be safer, especially when you have a cub in tow!
Ares’ yearling has one more year left with mom and should be soaking up as many hunting lessons as possible, especially as we enter the spring seal pup season! At this time of year, accessible food is abundant as blubbery seal babies rest naively on the sea ice, making them (relatively) easy snacks to gobble down and fatten up on. Ares and her yearling are currently in an area we know has seals, so we hope they can feast on fat and gain as much weight as possible over these coming months before they head back to land this summer.
X33653 - AAC Bear - Arctic Ambassador
Eleven-year-old Arctic Ambassador and her two yearlings have covered a relatively small region of Hudson Bay since October. They spent their entire on-ice season zig-zagging in a midwestern portion of Hudson Bay, never heading very far north or south. This is likely a smart play for this trio, who have travelled over 1,202 km. Why move farther than necessary if the eating is good?
After being fairly close to the coast of Nunavut in late February, the family has since headed a bit north, then looped slightly south, seemingly headed back toward the Churchill area. But, they could veer off course at any time! Arctic Ambassador should be enjoying this spring season as she teaches her yearlings to hunt while there are plenty of seals to feast and fatten up on - we know they are in an area that’s good for seals. This whole family needs to gain as much weight as possible before summer comes, during which they will be forced to fast on land for months, surviving off of whatever fat they can put on now. We wish them a very happy and fat hunting season!
X33991 - Frontiers North Adventures
This remarkable 6-year-old mom is on the move with her two yearlings: one biological and one adopted. This family has racked up over 1,600 km since late October, cruising across to the centre of Hudson Bay, then heading a bit south, then northwest, then southwest, then looping northeast again since early March — whew! This trio is easily outpacing many of the other families as they enter the best hunting time of the year: spring. They will be navigating the ice, avoiding males, and following their noses while feasting as often as possible.
These yearlings have one more year left with their young mom, and how lucky they are - especially the adopted cub. As a polar bear cub, the only way to survive in this environment is to have a mom to feed you, teach you about hunting, and keep you out of harm’s way. We wish this young family the best of luck in getting as fat as possible, sticking together, and returning safely to land this summer!
Since starting in Wapusk National Park last October, travelling up the coast to just east of Churchill, and getting onto the sea ice in late November, Vicky and her yearling have consistently stayed on the move. This little family has racked up over 1113 km while covering. They are currently in north-central Hudson Bay after doubling back over previous locations a couple of times, which may mean there was good food to eat there. Of all our Tracker bears, 15-year-old Vicky is currently the most eastern and one of the most northern, though recently she’s been on a southwest stint.
This yearling has one year left with mom, so it needs to listen to all the lessons, especially during the prime spring hunting season. Vicky will be fattening herself and her offspring up as much as possible in preparation for the lean summer months ahead. She is old enough to have some great experience navigating sea ice while sniffing out seals, so we hope she gains a lot of weight in the coming months, ahead of her journey home.
X32465 - PBI Storytelling - Ursula 2.0
Many of our Tracker bears clearly favour western Hudson Bay, but Ursula 2.0 is maybe the most west coast! At 22 years old, this experienced mom knows what she likes and how to take great care of her yearling, and she is clearly choosing to travel in an area that she knows well. Except for one short foray into the centre of the bay in late December, this family has travelled over 1,700 km (more than many other moms!) back and forth along the coasts of Manitoba and Ontario for months. And why not? There are definitely seals in this area, and the ice may be more stable near the coasts compared to the middle of the bay.
We trust that Ursula 2.0 knows what she’s doing and is spending the time to teach her yearling all there is to know about being a polar bear, hunting seals, and staying safe. We hope this family gets very fat in the next few months before they have to return to land. If they stay so close to the coast, they won’t need to travel far back to land when the time comes — a smart energy-saving strategy!
We are so excited to share that 21-year-old Siku left her den as of mid-March! After taking some time near her den to strengthen her cub(s)’ legs, she is now headed to the sea ice with a cub (or two, or three!) after many, many months of fasting in her den.
Siku came onto land last summer, entered a den in the fall, gave birth in late December, then nursed and cared for her cub(s) over the last few months as they grew bigger and stronger. That’s a long time without Siku having a meal for herself. Luckily, she timed her den emergence to coincide with the best hunting period of the year, seal pupping season, meaning there is plenty of relatively easy, very blubbery prey available to gorge on. And Siku deserves a feast! She will need to gain back as much weight as possible after losing hundreds of pounds over the previous 8 months while taking care of her tiny, vulnerable offspring.
Once on the ice, Siku likely won’t head too far out on Hudson Bay. She will likely prefer to stick close-ish to the coast to travel on more stable ice, avoid adult males, keep her little cubs from needing to do big swims, and make sure her trip back to shore this summer is short. We can’t wait to see where Siku goes next, and we wish her and her new cub(s) the best of luck!
X33532 - Natural Exposures - Portia
Portia is about to be single and ready to mingle. This 14-year-old has two two-year-olds with her, but not for long. These cubs are about to be weaned, if they’re not already, and will become subadults once on their own. This will be a tough time for them, but we trust that New Portia has taught them well about how to hunt and navigate the shifting ice.
In the meantime, New Portia will be hunting as many seals as possible and getting as fat as she can in preparation for mating and getting pregnant. Portia will need to be very fat to sustain a pregnancy over the summer, fall, and winter, so we hope she is finding lots of seals throughout her travels, which really have not been all that strenuous so far at 876 km. New Portia has stayed mostly in the western/central parts of the bay as she has consistently headed north; we will see when she decides to turn back around to head home. We wish her the best while she says goodbye to her two-year-olds and begins a new chapter!
An experienced mom at 22, Aurora has two two-year-olds, but not for long. She will soon wean these youngsters (if she hasn’t already) to become subadults who then must head out on their own.
Aurora will then be single and ready to mate, which will see her release pheromones through her footpads to help males track her across the vast icescape. As she waits for male suitors, she will enter a state of “hyperphagia” where she will eat as much as possible and gain tremendous amounts of weight in hopes of getting, and staying, pregnant. Extra hundreds of pounds of body weight will ensure that her body is able to fast ashore this summer, enter a den this fall, give birth over the winter, and not emerge again to eat until next spring.
Aurora is in the northern part of the bay right now, an area she seems to like, and is a serious traveller with over 3,700 km covered since the fall of 2024. She knows what she’s doing at her age, so we wish Aurora the very best as she sets out to have what is likely one of her last litters.
X33570 - Explore.org - Betty White
Betty White is another bear about to be single and ready to mingle. She will soon wean her two offspring and, as they head off as subadults, gorge on food while her body prepares to mate again.
Fourteen-year-old Betty White will develop stinky feet to help males track and find her across the vast sea ice, which would otherwise be tough: as our biggest traveller on the Bear Tracker, Betty White has moved up, down, and all around Hudson Bay over the last few years, racking up over 6,000 km!
Currently in the northern portion of the bay, Betty is entering hyperphagia as she eats as much as possible in plans to gain hundreds of pounds of weight to help her body sustain a pregnancy over the summer, fall, and winter. She has a long year ahead, so we hope she can get as fat as possible over these next couple of months as she gorges on blubbery seal pups. Though we don’t like to pick favourites, she’s definitely one of our most intriguing mamas, and we can’t wait to see where she goes next!
