RUSSIA/Most people have seen a polar bear, usually at the local zoo. And most zoo-goers know that wildlife advocates worry about the big white bears’ future as their icy Arctic habitat literally melts away as a result of global climate change. But apparently more than the climate is changing above the Arctic Circle.

The new mammal around the North Pole is the grolar bear, a hybrid created when a polar bear and a grizzly bear mate. Then there’s the narluga, a hybrid of the narwhal and beluga whale. The presence of these two new creatures and others produced by cross-breeding may be caused when melting sea ice allows them to mingle in ways they couldn’t before, according to a comment in the journal Nature.

These hybrids could push some Arctic species to extinction, the three American authors said in their Nature piece. They identified 22 marine mammals at risk of hybridization, including 14 listed or candidates for listing as endangered, threatened or of special concern by one or more nations.

CANADA“Some people may say these are just a few freaks. Others will say the sky is falling,” lead author Brendan Kelly, of the University of Alaska at Fairbanks, told the Natural Resources Defense Council’s OnEarth website.

“What we’re saying is that these are a few of the many examples of hybridization happening among marine mammals in the Arctic right now. It fits with what we would expect as a result of the rapid change in Arctic habitat. This sort of hybridization may be happening with more frequency, and we should pay attention.”