December 16, 2010
WAY TO BURY THE LEDE:
Mating Mystery: Hybrid Animals Hint at Desperation in Arctic (Janelle Weaver, Dec 15, 2010, LiveScience)
An odd-looking white bear with patches of brown fur was shot by hunters in 2006 and found to be a cross between a polar bear and a grizzly bear. Apparently, grizzlies were moving north into polar bear territory. Since then, several hybrid animals have appeared in and around the Arctic, including narwhal-beluga whales and mixed porpoises.The culprit may be melting Arctic sea ice, which is causing barriers that once separated marine mammals to disappear, while the warming planet is making habitats once too cold for some animals just right. The resulting hybrid creatures are threatening the survival of rare polar animals, according to a comment published today (Dec. 15) in the journal Nature.
A team led by ecologist Brendan Kelly of the National Marine Mammal Laboratory counted 34 possible hybridizations between distinct populations or species of Arctic marine mammals, many of which are endangered or threatened.
"The greatest concern is species that are already imperiled," said Kelly, first author of the Nature comment.
The ease and frequency of the mating demonstrates that they are neither species nor endangered.
