significant avifauna reported in the reserve are the great blue heron ("ardea herodias"), yellow-crowned night heron ("nyctanassa violacea"), snowy egret ("egretta thula"), mallard ("anas platyrhynchus"), belted kingfisher, "megaceryle alcyon" and northern waterthrush ("parkesia noveboracensis"), which are all wintering bird species. feral pigeons, which are displacing tropic birds from their nesting sites in cliff-holes and ledges, need to be eliminated from the reserve to preserve the native species of birds, according to efforts made to control their population thus far.