JACKSON, Wyo. (AP) — Biologists think there's a risk of another pneumonia outbreak developing among Jackson Hole's bighorn sheep herd.

The Associated Press reported Monday that ten of 14 sheep darted earlier this month tested positive for a bacteria linked to bighorn die-offs in the West.

Biologists took samples from the animals because of a high death rate among radio-collared sheep. Six of the 20 tracked sheep have died since the summer.

The tests of the darted sheep did yield some good news. Game and Fish wildlife biologist Doug Brimeyer said none of the 14 had a more dangerous pathogen and all had good fat reserves.

The area's bighorn sheep herd was cut in half by a pneumonia outbreak in 2002 and the population took years to recover.