
Arctic Foxes Compete with Red Foxes
Clip: Episode 4 | 3m 19sVideo has Closed Captions
Red foxes are moving further north following the encroachment of the tree line.
As the climate warms, the boreal forest is advancing further north. With the tree line comes the red fox a competitor of the high Arctic specialist, the Arctic fox. The trees advances aren't just a problem for the Arctic foxes but for the planet as a whole, the darker tree cover absorbs more heat and decrease the albedo effect which further warms the planet, causing the cycle to start again.

Arctic Foxes Compete with Red Foxes
Clip: Episode 4 | 3m 19sVideo has Closed Captions
As the climate warms, the boreal forest is advancing further north. With the tree line comes the red fox a competitor of the high Arctic specialist, the Arctic fox. The trees advances aren't just a problem for the Arctic foxes but for the planet as a whole, the darker tree cover absorbs more heat and decrease the albedo effect which further warms the planet, causing the cycle to start again.
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Evolution Earth
Traveling to the far corners of the world, we discover the extraordinary ways animals are adapting to our rapidly changing planet. We witness nature’s remarkable resilience, as our perception of evolution and its potential is forever transformed. Read these interviews with experts to learn more.Providing Support for PBS.org
Learn Moreabout PBS online sponsorship[Shane] but this ice world specialist is having to deal with an invader, whose presence signals a problem for our planet.
♪ The new arrival is a wily cousin... the red fox.
♪ [Arctic fox yelps] He, too, is no slouch when it comes to catching lemmings... [sniffing] ♪ and he does it in style.
♪ He's bigger and more aggressive, and he bullies the smaller Arctic fox out of his territory... ♪ but this competition is not as simple as it seems.
Unlike the Arctic fox, the red fox is not so well adapted to survive the blistering icy winds of the Arctic plains... but he does not come alone.
♪ He's backed up by a force much more powerful than himself.
♪ Moving north with him is an army... a wall of trees.
Warming temperatures are allowing the forest to move north, invading the Arctic, lending enough shelter for the red fox to take over this territory.
Now typically, we think of trees as having a positive impact on the climate, but out here they don't have the effect you might expect.
Snow reflects up to 80% of the sun's rays... but the trees darken the tundra, canceling this reflective quality, so the land absorbs more of the sun's heat.
Trees have been found to raise the temperature in the Arctic by nearly two degrees... and this heating effect is a feedback loop.
The more the land warms, the more the trees advance, accelerating climate change as they go.
Video has Closed Captions
At the planet’s frozen extremes, animals can reveal the changes taking place. (30s)
The Impact of the Broad-tailed Hummingbirds' Migration
Video has Closed Captions
billy barr tells us the lilies emergence is out of sync with the hummingbirds arrival. (7m 35s)
Preserving the Tundra with Reindeer
Video has Closed Captions
Reindeer are playing a crucial role in preserving the tundra by eating forest vegetation. (7m 37s)
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