Because West Nile virus (WNV) causes the death of certain kinds of birds, especially crows and blue jays, reporting and testing of dead birds has historically been a way to detect WNV activity in an area. In recent years, however, the tracking and testing of dead birds has become less useful for monitoring WNV activity.Many other states have also discontinued dead bird reporting and testing. Mosquito collection and testing provides a more reliable indication of current WNV activity. This is where monitoring efforts will be focused.