INHS Ornithologist Steve Bailey told the Chicago Tribune that Danville has "the largest winter roost of crows that we know about in the U.S. and Canada." Christmas Bird Counts found 121,500 crows, whereas a year ago, the count was 238,000. INHS Affiliate Mike Ward added that the drought caused a resurgence of West Nile virus, to which crows are particularly vulnerable. Crows rebound well, which might be bad news for the residents of Danville who have unsuccessfully tried many things including trucks with a "cannon" booming to scare the birds.