This latest report comes from the Arctic circle, one of the most extreme places on the planet. I'm here to learn about the world's largest land carnivore, which can survive freezing temperatures of minus 30 degrees centigrade – the polar bear.

For the last three years, WWF has followed in the tracks of polar bears on the Arctic islands between Norway and the North Pole. But finding these bears in such a remote place isn't easy – especially as they can swim for miles and walk huge distances every day.

So, to follow these animals and learn more about them, WWF has fitted radio-collars to two bears.These radio collars send signals to a satellite in space which then beams information on the bears' whereabouts back to WWF scientists.

To fit the collars, the bears were found by helicopter and then darted with a tranquiliser by a specialist vet. Once a collar has been fitted, the bears are measured and blood samples are taken to check they are healthy. When this is done, the bears are given another harmless drug to wake them up.

One of the bears collared is "Peggy 2183" – an eight year old female who weighs 163 kg (over 25 stone!). Peggy has two cubs. Sporting the latest in satellite technology, Peggy is now showing scientists how polar bears behave in their Arctic environment.

Peggy will also provide information on how the animals may be affected by climate change. Sadly, polar bears are under threat from climate change.

As Earth heats up, the sea ice in the Arctic decreases. But polar bears rely on sea ice to hunt their favourite food - seals. With the ice disappearing, polar bears are finding it harder to hunt.

There are only around 22,000 polar bears left in the world, but this number could fall if the Arctic continues to warm at twice the rate as the rest of the world. But for now, Peggy and her cubs are doing well.

Peggy's radio collar showed that she and her cubs were spending most of her time on the sea ice off the Norwegian islands of Svalbard. But this ice melted and they were forced onto land. You can keep track of Peggy's movements yourself by logging on to WWF's Polar bear tracker.