Road deaths can kill nearly a third of a hedgehog population and push smaller communities towards extinction, a new study has shown. A team led by researchers at Nottingham Trent University (NTU) studied four hedgehog populations of varying sizes in Nottinghamshire to judge the effect of traffic kills on animal numbers. The study found such collisions killed between 15% and 29% of a group each year, and was the main cause of recorded hedgehog deaths, amounting to about two fifths of the total. While larger populations saw more deaths, their numbers overall were more stable, but smaller groups could be "devastated" by the loss of "just one or two".