Caribou herd (IMAGE) University of California - Davis Caption A herd of caribou in arctic Greenland. Caribou at this study site have been declining over the past several years, while muskoxen have been increasing. Such herbivores help rare plant species persist in a rapidly changing climate. Credit Eric Post, UC Davis Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.