Increasingly mild winters have caused an abundance of acorns and beech nuts in Europe's woodlands, writes Paul Brown, triggering a wild boar population explosion – just one of the effects of warming climate on wildlife populations.​Wild boar populations in Europe are getting out of control – and scientists are blaming climate change.There are now millions of wild boar spreading out from their preferred woodland habitat, moving into city suburbs, and even crossing national boundaries to countries that had thought they were extinct.