Protected natural areas across Europe are changing. Climate change, with rising temperatures and heavy rainfall, is turbocharging the growth of shrubs and trees, choking the flowers and insects that need the light and heat of open spaces. Traditionally, this scenario prompts nature managers to reach for chainsaws and brush cutters to keep the landscape open. But researchers at Aarhus University and the Natural History Museum, Aarhus, Denmark, can now show that horses and cattle represent a more...