UNDERC is home to a great diversity of vertebrate species.
The many lakes and streams support populations of many fish species, including large and small-mouth bass, muskellunge, northern pike, and walleye. Several minnow species can also be found in the smaller lakes and ponds.
The wide variety of aquatic habitats host a rich diversity of amphibians at UNDERC (10KB), such as frogs including green frogs, wood frogs, and eastern gray treefrogs, and several species of salamanders occur in the forests at UNDERC (including Blue-spotted and Red-backed Salamanders).
Common Snapping Turtles and Western Painted Turtles dominate the reptile community at UNDERC (10KB). Many non-venomous snakes (Red-bellied Snake, Eastern Garter Snake, and Eastern Smooth Green Snake) can also easily be found.
A large number of avian species is hosted at UNDERC (19KB), including those associated with lakes and wetlands (Bald Eagle, Osprey, American Woodcock, Sandhill Crane, Common Loon, Wood Duck) and those associated with upland forest habitat (Cooper's Hawk, Barred Owl, Ruffed Grouse, Pileated Woodpecker, Red-breasted Nuthatch). In addition, UNDERC gets many avian visitors throughout the summer including warblers (Ovenbird, Black-throated Green Warbler, American Redstart, Chestnut-sided Warbler, Northern Parula) and flycatchers (Least Flycatcher, Eastern Wood Peewee, Eastern Phoebe).
Mammalian diversity at UNDERC (12KB) is high, with a species-rich small mammal community including several species of shrew, deer mice, jumping mice, and sciurids, such as flying squirrels, chipmunks and pine squirrels. There are also several mustelid species as well, including fisher, long-tailed weasel, ermine, and river otters. There are also many larger herbivorous species, including beaver, white-tailed deer, and porcupine. Finally, many larger carnivores occur at UNDERC, such as black bear, gray wolf, and bobcat.