Due to a range of geological characteristics and elevation, the Appalachian forests of Western Maryland contain a wide variety of different forest types. These mature and diverse forests are crucial for species of forest interior dwelling birds such as the Northern Goshawk, the Sharp-shinned Hawk, the Least Flycatcher, and the Cerulean Warbler. However, they are threatened by increasing fragmentation due to timber harvesting and development, and by the encroachment of non-native invasive species.