Global warming has resulted in a flock of wild sheep on a remote northern Scottish island to become smaller, according to an strange investigation published on Thursday.
On the average, wild Soay sheep on Scotland’s island Hirta are 5 percent smaller today than they were in 1985, according to a team of researchers led by Tim Coulson of Imperial College London.
He explains: “In the past, only the big, healthy sheep and large lambs that had piled on weight in their first summer could survive the harsh winters on Hirta. But now, due to climate change, grass for food is available for more months of the year, and survival conditions are not so challenging – even the slower growing sheep have a chance of making it, and this means smaller individuals are becoming increasingly prevalent in the population.”
The research, published in the July 2 issue of Science, says global climate change as a likely reason. Survival conditions on Hirta are becoming less difficult, which means slower-growing, smaller sheep are more likely to survive the winters than they once were.
The research team also says a ‘young mum effect’, whereby these smaller, younger animals are having relatively smaller offspring, because they are unable to produce large lambs.
“Sheep are getting smaller. Well, at least the wild Soay sheep living on a remote Scottish island are. But according to classic evolutionary theory, they should have been getting bigger, because larger sheep tend to be more likely to survive and reproduce than smaller ones, and offspring tend to resemble their parents,” said co-author, Tim Coulson of Imperial College London.