Most tall-grass prairie in Canada has been lost over the last century, and the little that remains is declining in quality due to human suppression of natural disturbances (like wildfire). Two small prairie butterflies (Poweshiek skipperling and Dakota skipper) have become critically endangered as a result. Manitoba is home to some of the last surviving Canadian populations of these species. The Nature Conservancy of Canada (NCC) uses grazing, mowing, and prescribed burning to try to mimic pre-settlement disturbances in sites that are occupied by these species. However, butterflies are sensitive to these activities, and could suffer further declines if their habitat is not managed appropriately. This project will determine a management regime that keeps prairie habitat in a pristine state while avoiding any damage to endangered butterfly populations. NCC staff will use the results to improve their habitat management plans.