Stahler_Yellowstone wolves (4) (IMAGE) University of Oxford Caption About half black and half gray, members of the Druid Peak Pack gather to howl at a neighboring wolf pack. Credit: Daniel Stahler/NPS Credit Daniel Stahler/NPS Usage Restrictions No restrictions. License Public Domain 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.