The Midwestern United States is a vast geographic region encompassing twelve states that stretch from the Great Lakes to the Great Plains. This expansive area features a variety of ecosystems, serving as a biological crossroads for North America. Habitats range from tallgrass prairies to deciduous forests and northern coniferous forests. The region’s biodiversity is shaped by the Great Lakes and the Mississippi River, along with countless smaller lakes and wetlands, supporting a rich array of wildlife.
Iconic and Common Midwest Mammals
The Midwest landscape supports a robust population of mammals, ranging from large ungulates to small burrowing species. The White-tailed Deer is the most widespread large mammal, thriving in almost every habitat due to its adaptability. In the western reaches, the American Bison, a keystone herbivore, now grazes in protected areas following a conservation resurgence.
Predators and scavengers are well-represented. The Coyote is found throughout the region, inhabiting both rural and urban environments. The Black Bear is confined mostly to the heavily forested northern states, such as Minnesota, Wisconsin, and Michigan. The Gray Wolf maintains protected populations primarily in the northernmost parts of Minnesota and Wisconsin, preying mainly on deer and moose.
Smaller mammals occupy various niches. The American Badger is adapted for digging burrows in open prairies, using its powerful claws to hunt rodents. Raccoons and Virginia Opossums are successful nocturnal animals that flourish in wooded and human-dominated areas. Common rodents include the Franklin’s Ground Squirrel and the Thirteen-lined Ground Squirrel, features of the prairie and grassland ecosystems.
Avian Residents and Migrants
The Midwest is geographically significant for birdlife, positioned beneath the Mississippi Flyway, a major north-south migratory corridor. This flyway follows the Mississippi, Missouri, and Ohio Rivers, providing stopover habitats for over 325 species annually. Approximately 40% of all North American migratory waterfowl and shorebirds rely on this corridor.
Waterfowl species congregate in the region’s wetlands and river pools. Ducks, such as the Mallard and Blue-winged Teal, along with Canada Geese and Tundra Swans, utilize the food and cover offered by the riverine and Great Lakes ecosystems. Diverse habitats also support raptors, including the Bald Eagle, often seen near large bodies of water.
Deciduous forests and riparian areas are important breeding sites for songbirds. Year-round residents like the Northern Cardinal and Blue Jay provide color even during the winter months. During spring and fall migrations, warblers, including the Kirtland’s Warbler, pass through the forests and prairies to forage. Game birds like the Wild Turkey and the Ring-necked Pheasant are common in wooded and grassland environments.
Herpetofauna: Reptiles and Amphibians
Midwestern herpetofauna includes species adapted to the region’s distinct seasonal temperature variations. Amphibians are reliant on wetland, forest, and prairie habitats for breeding and foraging. The American Toad and various Tree Frogs, such as the Gray Treefrog and the Western Chorus Frog, emerge in spring to reproduce in temporary pools of water. Salamanders, requiring clean, moist environments, are represented by species like the Eastern Tiger Salamander and the Blue-spotted Salamander, which spend most of their adult lives underground.
Reptiles, including turtles and snakes, are more visible in the warmer months, often basking to regulate their body temperature. Turtles are common in the region’s lakes and rivers, including the widespread Painted Turtle and the Common Snapping Turtle. Terrestrial reptiles include the non-venomous Common Garter Snake, one of the most widely distributed snakes in the area. A few venomous species, such as the Eastern Massasauga Rattlesnake, are limited to isolated wetland areas.
Freshwater Ecosystem Dwellers
The aquatic life of the Midwest is defined by its massive freshwater resources, primarily the Great Lakes and the Mississippi River system. These waters support an immense fishery, contributing to the region’s ecology and economy. The Great Lakes, which hold about 21% of the world’s surface fresh water, are home to approximately 250 species of fish.
Popular game fish in the Great Lakes include Walleye, Lake Trout, and Chinook Salmon; the latter two were introduced to manage invasive species populations. The deep, cold waters also harbor unique species like the deepwater sculpin and the opossum shrimp. In the Mississippi River, nearly 150 native fish species thrive in its complex network of main channel, backwaters, and tributaries.
The river system is noted for large bottom-dwelling fish, such as the Channel Catfish and the ancient Lake Sturgeon and Shovelnose Sturgeon. Freshwater mussels are ecologically significant, particularly in the Mississippi River basin, where they are a hotspot for diversity. These filter feeders play a substantial role in maintaining water quality. Crayfish are another common aquatic invertebrate, serving as a food source for many animals.