About 39 species of mammals have been identified at Great Swamp National Wildlife Refuge. Common species include white-tailed deer, red fox, raccoon, gray squirrel, coyote, river otter, and muskrat. While some species are common on the refuge, they are rarely seen do to their elusiveness. Transient black bears have also been observed on the refuge.
Some of the very important species for controlling the insect population on the refuge are the 10 bat species found here, including the eastern red bat, eastern small footed bat, northern long-eared bat, and hoary bat, little brown bat, big brown bat and federally endangered Indiana bat.
Download the mammals brochure (pdf)