Few animals dominate their habitat quite like the polar bear. Lions may be kings of the jungle, but polar bears are unquestioned emperors of the Arctic.

Or at least they used to be.

The giant carnivores have occupied the region for some 100,000 years, giving them time to become the ideal polar predator. Even as humans started arriving in recent millennia — technically replacing polar bears atop the food web — the effect was minimal. Arctic people forged a sustainable relationship with the bears, killing only what they needed and otherwise steering clear.

Over the past few decades, though, the basis for all these adaptations has begun to crumble. The Arctic is quickly changing after a long era of stability, largely due to rising temperatures and shrinking sea ice. Oil rigs and shipping also loom large, and even grizzlies pose a threat.

All this led the U.S. to classify polar bears as threatened in 2008, and inspired Canada to express "special concern" earlier this year. Many experts project a grim future for the species, although some research also suggests it's not too late to intervene.

To highlight this pivotal point in Arctic history, MNN has rounded up nine of the most awe-inspiring polar bear videos online. These clips showcase the bears' versatility — not just their capacity for violence, but also for affection, curiosity and cleverness — at a time when they need all the appreciation they can get.

1. A bone to pick: It's often best to stand your ground in a bear encounter, although much depends on the species and the situation. Polar bears, for example, can be especially persistent, but this Russian photographer was lucky enough to be wielding what looks like a giant femur when three polar bears approached him:

2. Dog's bollocks: Named Aki, this is one of several dogs employed to scare away polar bears from a human settlment in Svalbard, Norway. It's life-threatening work, but Aki seems to have a handle on things:

3. Bear hugs: Not all dogs share Aki's dislike of polar bears. In fact, they can be surprisingly tolerant, as this video from northern Canada shows:

4. Cold pursuit: Thanks to the BBC's "Spycam," this video shows a polar bear's careful pre-attack planning. It also shows how terrifying life as an Arctic seal must be:

5. Sealing the deal: If the previous clip left you unsatisfied, here's what happens when the seal doesn't get away (fair warning — it's not pretty):

6. Curiosity killed the camera: Remember the Spycam from earlier? Here's a good reminder of why such up-close polar bear photography is best left to drones:

7. Amore in the Arctic: Love takes time, but it's more urgent if you're an endangered species. Still, this female polar bear seems willing to wear down her reluctant beau:

8. On thin ice: Despite their swimming skills, polar bears can't compete with seals in the water. They instead rely on sea-ice platforms to help them hunt from above, and those are increasingly scarce as the Arctic heats up. This video illustrates the problem:

9. Young and restless: Polar bears may be in dire straits, but two studies in 2010 suggested it's still not too late to save them. Some populations are healthier than others, and public awareness of their plight has grown in recent years. This final video features two cubs from what could be a bellwether generation for their species:

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