Polar Bears Shrinking Because of Pollution and Climate Change
Pollution and climate change are "stressing" polar bears out so much that they are shrinking.
In a study that was recently published in the Journal of Zoology, scientists found that physical "stress" caused by pollution and climate change has made it more difficult for polar bears to grow as large as they once did.
The scientists compared three hundred polar bear skulls from the last century and this one. The polar bear skulls changed in shape and shrunk size, indicating that polar bears became smaller.
The scientists think that pollution and melting ice make it harder for polar bears to hunt their prey. As a result, the polar bears became smaller because they had to spend less energy on growing and more energy on finding food. Their skulls may have also changed in size because of the impact of chemical pollutants.
"Because the ice is melting, the bears have to use much more energy to hunt their prey," explained Cino Pertoldi, professor of biology from Aarhus University and the Polish Academy of Science, and lead scientist in this study.
"Imagine you have two twins - one is well fed during its growth and one is starving. (The starving) one will be much smaller, because it will not have enough energy to allocate to growth."