Wren (IMAGE) Durham University Caption Wrens have been increasing in northern European areas where winters are becoming milder, but declining in some southern countries where summers have been getting hotter and drier. Credit Dr. Stephen Willis, Durham University Usage Restrictions None 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.