Beavers are now found along large rivers and streams, although the original population was extinct by 1820. Beavers are rar ely seen, but evidence of their presence is the gnawed trees along rivers such as the Batsto, Mullica and Oswego. River Otters and Long-tailed Weasels are also rarely seen but present along streams. Raccoons and Gray Foxes are common throughout the area . There are no vertebrate species strictly confined to the Pine Barrens, but the area does support a rather unique community of plants and animals not found elsewhere in New Jersey.
Many characteristic species are southern species which reach their nor thern limit in New Jersey.
The protection afforded by such recognition is necessary to save these species from extinction, but the protection of such organisms' natural habitat is of even greater importance. Maintaining a large, relatively-undisturbed portion of the Pine Barrens is necessary to preserve its fauna since most wild animals cannot survive in close association with man. Aquatic habitats and the organisms they support are especially vulnerable to human disturbance. Protecting complete drainage systems may be necessary to preserve the unique acid-water fauna of the Pine Barrens. There is some evidence that modifying streams by sewage disposal or agricultural run-off has resulted in establishing populations of species not common in the Pine Barrens and reducing populations of typical Pine Barrens species.