Why are some animals moving north?

I've noticed that more and more animals seem to be moving north these days. This is not the same as the migration (traveling) that some animals do every year when the seasons change, so I asked Henrietta what's going on.

She explained to me that the weather all over the world is quickly changing. This is called global warming or climate change. This means that pollution in the air is trapping heat, and causing the planet to warm up.

Because of this, many species (types of living things) are moving north to find colder places to live. Scientists have noticed that in England, the silometopus spider and the comma butterfly have moved their homes 200-300 km north. In Canada, we can now see over 70 species of tropical fish (like triggerfish and flying fish) in Nova Scotia's waters!

The Altantic White Fish is unimpressed with his new neighbour

"What's wrong with that?" I asked Henrietta. I thought it would be neat to see tropical fish up north! Henrietta told me that this is not a good thing at all, because the species normally living in the north could disappear as more species from the south move in.

For example, as temperatures get warmer, red foxes are moving north into areas where Arctic foxes usually live. Since red foxes are bigger than their Arctic cousins, and the two don't normally live side-by-side, it could be more difficult for Arctic foxes to survive while the bigger red foxes take over.

Arctic fox was never pleased when her cousin red fox came to call

Grizzly bears are also moving north, into areas where there used to be just polar bears. Because of this, we are seeing baby bear cubs that are half grizzly and half polar bear, which could mean that both the grizzly and the polar bear could disappear.

Scientists are continuing to study how changing temperatures are affecting plants and animals all over the world, so hopefully we can find ways to protect species that are at risk.