A recent article and video feature a study that explores keys to wolf pack breeding success in Yellowstone National Park. The study concludes that female body weight and pack size are the most important variables determining reproductive success and pup survival. The study also suggests that in addition to being a valuable ecological tool, wolves have proven to be an “excellent model for the study of sociality and cooperation.” Article from the UCLA Newsroom: http://newsroom.ucla.edu/portal/ucla/yellowstone-wolf-study-reveals-239545.aspx