Science Update - Sea Levels and Foxy Foxes

Bob -   This week for The Naked Scientists we're going to talk about why melting polar ice sheets may not be the biggest contributor to a sea level rise in response to global warming.  But before we get too serious, our new Science Update reporter Susanne Bard's going to tell you about how some foxes are mixing it up in the high arctic.

Susanne -   In foxes, wolves and coyotes, males and females often share the parental duties, bringing in food and protecting the young.  And for many years, researchers thought these species were monogamous.  But a recent study of arctic foxes on Bylot (Bye-Let) Island in Canada suggests otherwise.  University of Alberta biologist Lindsey Carmichael and her colleagues took DNA samples from 49 arctic foxes.  Carmichael analyzed the DNA fingerprints of the babies and found that some of the furry canines had different fathers from their siblings. 

Lindsey Carmichael (University of Alberta) -  What we found was that in 75% of dens the foxes were monogamous but in the other 25%, they were not.

Susanne -   Carmichael thinks that increasing the genetic diversity of a mother's litter in any given year could improve the odds that one or more of her pups will survive.

Bob -   Thanks, Susanne.  On a more serious note, we know that sea levels are rising because of global warming.  If they rise by just a few feet, it could devastate or even submerge coastal cities.  The best-known contributor is the melting polar ice sheets.  But according to a study by University of Colorado geological scientist Mark Meier and his colleagues, 60 percent of the world's ice melt actually comes from glaciers and smaller ice caps scattered across the globe.

Mark Meier  (University of Colorado)  -  And we also project to the future that this contribution will be greater than that of the ice sheets, at least to the end of this century.

Bob -   He adds that glaciers and ice caps melt faster than polar ice sheets, because they're smaller.  And what's more, melting ice can lubricate glacier beds so they slide more quickly into the sea. 

Susanne -   Thanks, Bob. We'll be back next week with more amazing science from across the pond.  Until then, I'm Susanne Bard...

Bob -   ...and I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists!