Source:
ReutersMelting ice drives polar bear mothers to landThu Jul 12, 2007 3:05PM EDT
WASHINGTON (Reuters) - Melting sea ice is driving mother
polar bears onto dry land to give birth in northern Alaska,
U.S. Geological Survey scientists reported on Thursday.
They found that just 37 percent of polar bear dens were
built on sea ice between 1998 and 2004, compared to 62
percent between 1985 and 1994.
"Right now, pregnant females foraging offshore in summer
must wait up to a month longer than they did even 10 years
ago for new sea ice to form so they can travel to denning
areas on land," USGS researcher Steve Amstrup said in a
statement.
"Alternatively, they must swim ever greater expanses of open
water to reach suitable land denning habitat or they must den
on ice that may not be stable enough to survive the winter."
Eventually, the researchers predicted, the ice will freeze so
late that bears will be stranded at sea too far away to reach
land safely. Pregnant polar bears must create dens to protect
new cubs from the Arctic winter.
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http://www.reuters.com/article/environmentNews/idUSN1235191720070712