It’s August and we’re officially in the hottest part of the year, which means the cicadas are buzzing and a dip in the lake is looking more and more tempting. For myself, a research assistant, observing polar bear behavior, the steamy summer months mean I’m being frequently asked the same question: aren’t the animals too hot?

The question makes a lot of sense, especially for polar bears, which are native to the Northern coasts of Alaska, Canada, Greenland, Russia, and Norway. Moreover, whenever we see polar bears in documentaries, books, and movies, they’re usually trudging through deep snow or swimming alongside icebergs.

However, that’s only half of a polar bear’s year. In the summer, much of the polar bear’s range warms to temperatures well above freezing. All that snow and ice melts and polar bears are left to spend their summer months on solid ground. In fact, the arctic summer is probably a good deal warmer than many suspect. For example Churchill, a city in Canada known for its large population of polar bears, averages 64 degrees F in the month of July. So polar bears are more than well suited for a summer free from snow and ice.

Still, 64 degrees is cooler than Chicago’s 80 degree average in July. To provide some temperature relief for the bears, the pools in their habitats are chilled to 59 degrees throughout the summer, and whenever the bears feel the need to cool down, they can jump into the water. Our world-class environmental quality staff also keep a close watch on how our bears are physically reacting to the heat of the summer months. The staff use something called a “thermal neutral zone kit” to make sure that the bears aren’t exerting too much energy and are keeping their internal temperatures at healthy, comfortable levels. If we find the bears are spending a lot of energy trying to stay cool or if we know the temperature on a given day is going to be especially warm, our animal care staff will give the bears access to their air-conditioned indoor habitats.

In addition to those husbandry measures, I am spending five days a week this month monitoring the bears for our current polar bear study. While collecting data on everything the polar bears are doing during my observation time, I also make special notes about the temperature, weather, and any behaviors, which could be welfare indicators. When we are done collecting data for this study, we will use it to examine how behavioral welfare indicators vary by season throughout the year.

Julia Machado
Behavioral Research Assistant
Published August 12, 2021