Gustav Hellstrom, Umea University (image) Umea University Share Print E-Mail Caption Gustav Hellström, assistant professor at the Department of Wildlife, Fish and Environmental Studies at the Swedish University of Agricultural Sciences in Umeå, is one of the researchers behind the study. Credit Alexander Ruas Usage Restrictions This photo may only be used in contexts related to this news release. Share Print E-Mail 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.