Rarely is a creature so beguiling as Earth’s largest living land carnivore: the polar bear. From popular culture appearances in movies to unusual and impressive behaviors recorded by scientists, polar bears continue to fascinate. Unfortunately, they are also synonymous with climate change, tied to their dependence on sea ice to hunt their prey and raise their cubs.
We spoke to Alysa McCall, Director of Conservation Outreach and staff scientist at Polar Bears International about what is really going on with these "white hairy canaries" of the Arctic. Recorded as part of The Big Questions, IFLScience’s podcast, we explore how the climate crisis is affecting polar bear populations, how monitoring polar bears from a monster truck actually works, and what can be done to keep these enigmatic animals safe.
Polar bears are the poster child for climate change, so how are the Hudson Bay population reacting to our warming planet?
Alysa McCall: Polar bears as the poster child for global warming is a bit cliché but there is a really good reason for it and of course, one of the reasons is the bears are so compelling, so they do get peoples’ attention.
Another reason is that there really is extremely strong evidence showing us that these polar bears are impacted by climate warming. Western Hudson Bay is one of 19 different polar bear populations around the Arctic. Because we’re in Churchill, which is relatively easy to get to compared to other parts of the Arctic, this is one of the most accessible populations we have of polar bears. That means these are the best-studied polar bears in the world and we have over 40 years of data on these bears.
At the same time, we have excellent sea ice data from Hudson Bay. This was the first population in the world where we were able to link changes in sea ice to changes in polar bear body conditions. We like to call these bears the fat white hairy canaries in the coal mine. They are telling us that as the polar bears see changes in the sea ice, they will be impacted and we will start to see that in other areas across the Arctic. We already have.
Specifically, what we have seen here is that in the 1980's we had around 1,200 polar bears in this area. Currently, 30 years later, that is about 800 polar bears, so that’s a decline. We are also seeing smaller bears, we are seeing fewer cubs. This area used to be quite famous for triplets. Hudson Bay was very productive, now we see a lot fewer of those triplet litters.
Basically, what’s happened is as we are losing our thick sea ice polar bears are spending longer periods of time on land than they used to, so three to four weeks and that is slowly increasing over time. This means during those weeks, they are losing access to their seal prey, so they don’t have access to the high-calorie blubber that they’re adapted to and that’s what they really need to survive. So less hunting and more living off their own body fat, and when they are on land, they lose up to about a kilogram a day. If you can imagine that extending, that does take a toll.
If you’re a healthy adult male and you have a lot of options for different prey because you’re big and strong and you know the area, you can probably go a little extra while without eating. You will have a limit, but where we’re really seeing the impact is on moms and cubs.
If you’re a pregnant female, you’re already at risk of going up to eight months without eating. These females come onto land about June/July. They’ll be going into the dens and giving birth from November through January and nursing until about March when they come back out on the ice. So we’re already asking these females to do so much and now we’re going to extend that by another month and even more in the future. We’re seeing these females get closer to the threshold where it’s hard to produce cubs and then get those cubs into adulthood. So, that’s really where we’re seeing the population decline, where we’re not getting the cubs into the adult population of polar bears here.
Do you see changes in the seal population at all?
AM: That’s a good question, it’s something we talk about a lot. Seals are even harder to study than polar bears because they like to live under the water. We know that the seals will be impacted also by changing ice patterns, but seals that polar bears predate on primarily are ringed and bearded seals, which are both ice-associated seals. So both of those species need ice as well.
When we start to lose the sea ice, the seals might have a harder time finding places to haul out; their birth lairs are made of ice and if it’s a very wet year, those can collapse. Another thing we are seeing in Hudson Bay here is that killer whales have been coming in in the last few years, which never used to happen. That’s because ice is opening up. Killer whales usually can’t be around sea ice because they have a dorsal fin. Arctic whales like belugas and narwhals do not, so they can get through the ice, but as the ice is opening up, killer whales are coming in, so now these poor seals have underwater predators where they used to just have the above-water polar bear. That might have some interesting impacts as well.
Actually, a couple of days ago out here there was a seal that was coming close to the shore and we were watching a polar bear just walk along the coast and all of a sudden this bear, we got this all on camera, the bear just dropped down, we didn’t know what was happening, and it just ran towards the water and stopped and was watching the seal. Anyway, long story short, the polar bear never got the seal but for maybe an hour we watched the bear stalk the seal up and down the coast.
Polar bears really do need to use sea ice as a platform to give them the advantage to hunt the seal. It's very hard to hunt a seal in open water, but man, that polar bear watched that seal. That seal was taunting the bear for a while. But it was so cool to watch that play out, we hadn’t seen that behavior before. We know it happens in the wild but it was very cool.
We're fascinated by your big buggy and all the tech that you guys have. Can you tell us more about how you collect your data?
AM: We have a massive antenna on the back of Buggy One, massive, and it’s getting the Wi-Fi from the town of Churchill. We can do that because the tundra is flat, so we can shoot internet out across the tundra and then grab it with the antennae, so, our connection is amazing. It’s taken over 10 years to get to this point, so a lot of work but we do have a few cool things also going on.
Also the polar bear cams, we have a cam on the buggy so we can drive around, find the best action and live stream to anyone around the world that wants to get a glimpse of these bears. It’s super cool.
We also have a few other projects going on. One, in particular, is this radar project. We are increasingly working with the idea of human-polar bear coexistence as these polar bears are spending longer periods of time on land, they’re getting hungrier, and they’re maybe more likely to come into communities in search of food. How can we keep communities safe and keep the polar bears safe and in the wild, so safe and separate? What we need to do is give the communities a lot of support.
There are a lot of different options that we can help with but one that would be good is an early warning system. If we can detect a polar bear before it enters town and give people time to get inside and get away then we have a better chance of keeping people safe and keeping the bears in the wild. So, this radar system, we're training it, but we’re basically teaching it what does a polar bear look like? If we can train this radar to know what a polar bear is compared to say, a human on a snowmobile, or a dog, or even a rabbit, then it can let people know. It can sound an alarm, it can turn a light on, it can text message an officer or something like that if it sees a bear coming in. So, we’re testing that out here and continuing to refine that work.
That’s incredible that you can train them to recognize what a polar bear looks like, presumably as they spend more time on land and come into contact with people a lot more.
AM: Exactly, yeah. We need to be able to offer a variety of different tools, low-tech and high-tech. There are communities all across the Arctic. Everyone has a slightly different geography, different sea ice patterns, and different relationships with polar bears. But if we just have a variety of options that we can help support communities with and they can choose what works for them or develop something else then we have a better chance of keeping both the people ad polar bears safe and protected as they spend longer periods of time on land.
What are people missing about the polar bears and the sea ice and that relationship?
AM: I think the crux of it is polar bears are ice bears. They’re the biggest bear, they are the only marine bear, and they’re the only bear that relies on Arctic sea ice. This bear cannot live on land long term. Without the sea ice, we don’t have the polar bear, but we can protect Arctic sea ice. We know that actions we take today can keep sea ice in the Arctic and polar bears in the Arctic. It will take us moving away from fossil fuels and using more renewable energies like solar and wind on a large scale, and just as a society in general, moving towards this cleaner, more renewal future for the polar bear, but also it’s about us.
Our future is so shared with the bear, everything we’re doing for them benefits us and vice versa. It’s important that we have that counterbalance to the government officials that will be [at COP27 and other climate conferences] and to really talk about these goals that we have that transcend borders and that benefit everybody around the world. We need to all be working together to protect all our futures.
It’s important to know that the polar bear is just an indicator and really the sea ice is part of a global problem that affects everyone.
AM: Totally. We like to say that Arctic sea ice is the Earth's air conditioner, and it really is. It’s so massive and reflective and cold, it helps cool our entire planet. So, when we lose Arctic sea ice, truly, our global climate is impacted. So it’s good for all of us to keep this Arctic sea ice.