Scientists Found Polar Bears Increasingly Feasting on Whales. Here’s What It Says About Climate Change
As climate change engulfs our planet rapidly, the most affected part of the world would certainly be the Arctic region which is experiencing adverse ecological consequences of global warming. Scientists have developed a strategy to track environmental changes by keeping tabs on the diets of polar bears. These Arctic natives are suffering due to sea ice loss and warming climates but exhibit impressive flexibility in their diets. An increased feeding on whales has been observed among polar bears debunking the previously believed fact that they eat only ringed or bearded seals, per a study published in the journal Ecological Indicators.
Lead researchers Melissa Galicia and Professor Gregory Thiemann have participated in a new research project at York University that monitored the eating habits and foraging locations of polar bears. They particularly focused on the Arctic territory of Nunavut and retrieved useful data that indicated environmental changes in the region. Polar bears are highly adaptable eaters and are not very picky about the food they consume. However, this aspect has negatively impacted the prey population of whales and seals.
“Prey species, like whales and seals, also need certain habitat conditions and because of environmental changes in the Arctic, some marine mammals, such as prey species of bears, are redistributing. You’re getting an increase in more sub-Arctic species, like killer whales for instance,” Galicia explained. She also noted that sea ice is an essential hunting component for polar bears. Hence, the reduction of ice has forced them to hunt less as prey is available more easily or simply prey on different species. An in-depth analysis of fatty acids, like omega 3s and omega 6s, found in fat tissues of polar bears revealed that bowhead whale carcasses were common in their diet.
This also indicated that the whales are moving further north from their usual locus due to global warming. The fatty acids act like fingerprints of polar bears with an existing fatty acid signature that makes it easier to keep track of the kind of diet the mammal is eating and the percentages of different prey consumed. The researchers anticipated that habitat changes will surge in frequency in the future due to the rapid ecosystem changes in the Arctic ecosystem. Professor Thiemann predicted that the rising temperatures in the Arctic and eventual increase in sea ice loss will unleash “profound cascading ecological consequences.” But he was unable to explain the kind of species that may be affected by these impending changes.
“By monitoring the seasonal prey consumption of polar bears, scientists can better keep track of where marine mammal prey species are showing up and their seasonal distribution,” the researcher added. When not hunting whales or seals, the melting ice has exposed the polar bears to less nutritious food sources like berries, bird eggs, and small animals. These food sources, even though healthy, do not suffice for the huge amounts of calories polar bears require resulting in significant weight loss and nutritional stress, per the American Museum of Natural History. This indirectly leads to increased mortality rates and population declines of the mammals.