Why are polar bear populations declining?

Researchers turn to studying energy to find answers to this question

A new bioenergetics model has uncovered that polar bears in the Western Hudson Bay have declined by half over the last several decades. The reason is loss of sea ice and fewer chances to hunt, researchers found using the model. In a study published in Science, researchers collected information from polar bear monitoring and captures that occurred over the last 42 years. They ran this data through a model that uses polar bears’ energetic needs in combination with environmental limitations to determine what drives population trends. The model revealed that sea ice loss and the resulting lack of hunting opportunities mostly drove about 50% of population decline since the mid-1990s.

Read the study in Science.

Header Image: A polar bear and its cub of the year near Churchill, Manitoba. Credit: Erinn Hermsen / Polar Bears International