Christer Nilsson, Umeå University (IMAGE) Umea University Caption Christer Nilsson, Professor at the Department of Ecology and Environmental Sciences at Umeå University. Credit Mattias Pettersson, Umeå University Usage Restrictions This photo may only be used in contexts related to this news release. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.