Final answer:
Grizzly bears may attack when feeling threatened, especially if startled or if they are with cubs. Climate change has expanded their habitat range, leading to more human encounters. Additionally, bears that have been fed by humans are more likely to search for food near human dwellings.
Step-by-step explanation:
Grizzly bears may attack for several reasons, typically related to protection, hunger, or when they feel threatened. Specifically, a grizzly might attack if it's defending its young, if a human startles it by coming too close, especially if the bear is protecting a food source.
Although grizzly bears do not commonly attack, occurrences can happen if they perceive humans as a threat to safety or food. In addition, environmental changes such as climate change have an impact on bear behavior, pushing them into new territories where they may encounter humans more frequently.
For example, since 2008, due to climate change, grizzly bear habitats have overlapped with those of polar bears, leading to unique hybrid species like the grolar bear. Also, bear encounters with humans can increase due to habitation changes and the fact that bears that receive food from humans are more likely to seek out human settlements looking for more.
It is a misconception that bears go into true hibernation, rather they enter a state of deep sleep during the winter where they can be awakened easily. The timing of their hibernation-like state is based on environmental cues rather than occurrences at random times, providing evidence of regulated physiological changes.