We now know wolves in Yellowstone have experienced three major outbreaks of CDV in 1999, 2005, and 2008 (figure 1); and during these outbreaks many other carnivores, including coyotes, foxes, cougars, black and grizzly bears, and likely badgers, were also infected ('canine' distemper is a misnomer—the virus actually infects a wide range of carnivore species; Almberg et al. 2010). Outbreaks of CDV are particularly lethal for young animals. Wolf pup survival in the northern region of the park during outbreak years was only 23%, as compared to 77% in non-outbreak years. Adults appeared less affected; but among those exposed to CDV for the first time, survival is roughly half of what it is normally. Once an individual survives a CDV infection, it is thought to be immune for life. As a result, it may take several years before an area has enough susceptible individuals to support another outbreak.