Damage to Structures
Herons are not known to damage structures.
Damage to Landscapes
Herons are not a significant threat to plants or turf.
Damage to Livestock and Crops
Their presence threatens fish and crawfish. Obvious signs of hunting include birds perched on trees or wires near raceways or ponds, hovering overhead and then plunging into the water, standing or stalking along the edges of ponds, or swimming and diving in the ponds. Because most fish are swallowed whole, few direct signs of damage are left behind. In these cases, the presence of whitewash (bird excrement), bird feathers, and/or bird footprints may be the only signs of bird predation. Additional observations should be made at night to verify bird depredation. Chewed or partially eaten fish may be a sign of predatory mammals, including raccoons, mink, and otters.
Herons also can transmit diseases to ponds, but researchers do not consider this source of disease to be significant.