In a serene section of City Park, the horses of the New Orleans Police Department's Mounted Division trot around a ring of dirt, about half a football field in size, over and over, with various annoyances placed in their paths.
First a man unfurls a flag as the horses pass. A few buck and whine, but eventually fall in line. Next, a blue tarp is thrown across the ground. Horses don't gauge depth well, and some hesitate on the unsure footing, requiring a rider's coaxing.