Vertical![]() Elephants gathered at a watering hole in the relative safety of Serengeti National Park. In unprotected areas with dense human populations, the animals showed higher stress hormone levels. | Horizontal![]() Elephants gathered at a watering hole in the relative safety of Serengeti National Park. In unprotected areas with dense human populations, the animals showed higher stress hormone levels. | Thumb![]() Elephants gathered at a watering hole in the relative safety of Serengeti National Park. In unprotected areas with dense human populations, the animals showed higher stress hormone levels. |