Fig 2. Monthly mean fecal cortisol metabolites levels measured in a socially and territorially stable wolf pack (Druid Peak 2007–2008) and in three unstable packs (Slough Creek 2007–2008, Druid Peak 2008–2009 and Blacktail Deer Plateau 2008–2009) in Yellowstone National Park (USA).

Error bars represent standard errors.