JACKSON, Wyo. (AP) — The population of non-native mountain goats is growing prolifically in the Teton Range in northwest Wyoming, while the number of native bighorn sheep is in a noticeable decline.

Counting bighorn sheep from a helicopter for the last three years, Wyoming Game and Fish Department biologists tallied no more than 57 bighorns in the Tetons, a considerable drop from a count of 96 in 2008.

Meanwhile, an aerial count found 43 mountain goats.

Both bighorn sheep and mountain goats inhabit the West, including Colorado, Montana and Idaho, but mountain goats generally live in different terrain.

However, in the Tetons, one goat was seen near the sheep.

The closeness is worrisome because goats can carry bacterial pathogens that can be deadly in bighorn.