Along the middle and lower reaches, the forest is secondary, betraying the heritage of banana farms and slash-and-burn practises used historically in this area. Today much of this area is protected as the Payne's Creek National Park. Here, relatively dense jungle canopy has returned, resulting in a closed canopy of approximately 15 to 20 metres in height. Yellow bay cedar and other significant sized broadleaf species abound, along with numerous tropical vines and thorny undergrowth flora. A machete is essential for exploration even where there is an established trail. Black howler monkey troops are plentiful, each troop maintaining a home range of 40,000 to 70,000 square metres in this forest.