Along with polar ice caps and sandy beaches, sheep on a remote Scottish island are gradually shrinking as a result of global warming, according to a study published today in the journal Science. The finding offers unusual proof that large animals already are having to adapt to changes wrought by climate change.
The average weight of sheep in the feral flock has been falling nearly 3 ounces a year since 1985, the researchers reported. The cumulative effect has been a 5 percent reduction in total body size. That trend had puzzled scientists, because they knew that evolution clearly favored larger sheep that are better equipped to survive the harsh winters of Hirta, a rocky outpost more than 100 miles west of mainland Scotland.
British and American researchers have concluded that warming temperatures have made it easier for scrawnier sheep to survive, thus reducing the average size of animals in the herd.
