As Europe experiences more mild winters — very likely an effect of climate change, researchers say — the continent’s wild boarpopulations are growing exponentially, according to research from the University of Veterinary Medicine - Vienna. The scientists identified the trend by comparing up to 150 years of data on annual boar population growth to temperature and precipitation records from 12 European countries. One factor behind the population surges is body-temperature regulation, the scientists say. In mild winters, wild boars need to use less energy to stay warm, leaving more energy for reproduction and piglet rearing. Another factor is bumper crops of the boars’ food sources, primarily acorns and beechnuts, which have become increasingly common over the last few decades. Wild boars are more likely to survive harsh winters if they have been preceded by a good year for their food sources, the researchers note.