Decline of Bighorn Sheep
How disease is affecting bighorn sheep in Idaho
Scientists attribute most of the decline in bighorn sheep numbers to a pneumonia-like disease.
Domestic sheep carry this disease and are resistant to it, but the disease can be fatal to bighorns. Because both species of sheep are naturally gregarious, they can interact and transmit disease when they both occupy the same range.
Infected bighorn sheep then spread the disease among their own herds. In 2004, 80% of the lambs in Hells Canyon died from a disease outbreak.
