Where did WNS come from?

Current thoughts on the origins of the fungus point to caves in Europe. However, the bats that hibernate in these infected European caves do not seem to be impacted by the disease. This suggests that the bats there may have built up natural immunities to the disease, something that bats in North America presently lack.

The first documented North American infestation of WNS occurred in Howes Cave in upstate New York in 2006. Exactly how the fungus crossed the Atlantic is currently unknown.