Oklahoma is a biological crossroads where eastern forests and western prairies converge. This unique geography, spanning from the Ouachita and Ozark Mountains to the arid High Plains, creates a diverse mosaic of ecosystems. The state is home to a remarkable variety of fauna, adapting to environments ranging from humid cypress swamps to dry, shortgrass prairies. Its wildlife includes species characteristic of both the American East and the Great Plains.
Mammals of the Plains and Forests
The open grasslands of western Oklahoma and the Panhandle are home to iconic Great Plains mammals, including the American bison. These regions also host the swift pronghorn, thriving on the expansive, open terrain. The White-tailed deer is the most abundant large mammal statewide, adapting well to eastern forests and agricultural lands.
Predator populations are widespread, with coyotes common across the entire state, and bobcats patrolling wooded areas. The dense, forested mountains of the east provide shelter for black bears and river otters. Smaller species are also abundant, such as the nine-banded armadillo, which has expanded its range throughout the state. The black-tailed prairie dog, a rodent, forms large towns that are a feature of the shortgrass prairie.
Reptiles and Amphibians
Oklahoma hosts over 140 species of herpetofauna, showing significant variation between the humid eastern and drier western regions. The state is home to seven venomous snake species, all of which are pit vipers. These include the Western Diamondback Rattlesnake, the largest venomous species, found in the arid west, and the Western Cottonmouth, which frequents southeastern swamps and waterways.
The Copperhead is the most commonly encountered venomous snake, recognized by its hourglass-shaped crossbands, and is found statewide except in the Panhandle. Non-venomous snakes are far more numerous, including the Bullsnake and the Speckled Kingsnake. The American Bullfrog, the state’s official amphibian, is the largest frog in North America and is found near permanent water bodies statewide.
Salamander diversity is concentrated in the moist, eastern forests, where species like the Spotted Salamander breed in temporary vernal pools. In the arid west, the climate favors species such as the Spadefoot Toads, which emerge only after heavy rains to quickly breed. Common turtles include the state’s official reptile, the ornate Box Turtle, and the Spiny Softshell Turtle, adapted to sandy river bottoms and lakes.
Avian Diversity and Waterfowl
Oklahoma’s location along the Central Flyway supports both resident and migratory bird populations. The state bird, the Scissor-tailed Flycatcher, is a striking species identified by its long, deeply forked tail. These migratory birds arrive each spring from Central America, performing elaborate aerial courtship dances over open fields.
Raptors are a common sight, with the Red-tailed Hawk and the Great Horned Owl being year-round residents. The state’s numerous lakes and reservoirs attract vast numbers of migratory waterfowl during the winter. Species like mallards, northern pintails, and various geese use these bodies of water as important stopovers.
Aquatic Life and Notable Invertebrates
The state’s extensive network of rivers, streams, and reservoirs supports a rich aquatic environment of over 170 fish species. Game fish are a primary focus, including the Largemouth Bass, Smallmouth Bass, and Spotted Bass, which are sought after by anglers. Catfish species, such as the Channel Catfish and the Blue Catfish, are common across the state’s deeper lakes and major river systems.
The invertebrate population features some distinctive arthropods, including the Oklahoma Brown Tarantula, the single tarantula species found in the state. The Striped Bark Scorpion is the most common scorpion species, found statewide under rocks and debris. Another notable invertebrate is the American Burying Beetle, a large, black and orange carrion beetle historically found in the eastern half of the state. This beetle plays a unique ecological role by burying small vertebrate carcasses.