According to new research, wild sheep on a Scottish island are shrinking. According to the study being published in the journal Science, the sheep are becoming smaller over time due to global warming.
On the Scottish island of Hirta, sheep have been studied since 1985. The researchers involved in the current study used data regarding body-weight measurements and key life milestones for female sheep. A computer model was used to predict how sheep size would alter due to natural selection and other conditions.
The team concluded that the sheep are shrinking due to global warming. The island has been steadily seeing more mild winters which has led to a greater availability of food. Whereas before sheep would have to put a great deal of weight on in order to survive, the mild winters are making this less of a survival factor. In fact, since 1985 the average sheep size shrunk five percent.
Tim Coulson, the lead author of the study and researcher at Imperial College London, stated: “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.”