Amphibians and Reptiles

Nineteen amphibian and reptile species are present on the refuge with nine species listed as a Montana species of concern (milksnake, western hognose snake, Great Plains toad, greater short-horned lizard, plains spadefoot toad, common sagebrush lizard, painted turtle, spiny softshell, and snapping turtle).

Amphibians and reptiles require a mosaic of habitats suitable for breeding or nesting, foraging, protection, and overwintering. Habitat linkages are required to meet all the life stages, allowing animals to migrate seasonally between different areas to feed, overwinter, and reproduce. The permeable nature of amphibian skin makes these animals extremely vulnerable to contaminants in the environment.

Tiger salamanders often live in rodent burrows during much of the year and migrate to shallow ponds to breed in the spring. Some may keep larval characteristics including external gills and larval body form and reach sexual maturity in a process called paedomorphosis or neoteny. These are strictly aquatic and may exist with individuals that metamorphose.

Boreal chorus frogs breed in glacial potholes and reservoirs and feed in moist areas around ponds, or move into terrestrial settings to feed on ants and spiders. Adults forage a half mile or more from breeding sites. They overwinter in underground rodent burrows or crevices. Northern leopard frogs occupy a variety of wetland habitats with relatively fresh water and few or no trees. They commonly feed in open or semi-open wet meadows and fields with shorter vegetation. They overwinter underwater on the bottom of deeper streams and ponds or springs that do not freeze to the bottom and are well oxygenated, sometimes under bottom rubble and debris.

Great Plains toads are found up drainages and on the prairie where they are seen around glacial potholes, stock reservoirs, irrigation ditches, and smaller coulees. They require clean water so heavily used stock ponds may not be conducive to breeding. They spend time underground sometimes in prairie dog burrows. They will forage 1 mile from breeding sites. Woodhouse’s toads are common along rivers, large lakes and reservoirs. They overwinter below the frost line in rodent burrows, crevices or among tree roots. Breeding occurs in river backwaters, stock reservoirs, larger ponds, or lakes. Plains spadefoot toads are found in more arid environments close to water. They spend much of their time underground, but will, depending on temperature and moisture, throughout the day, emerge from and retreat to burrows dug with the spur on the back of their feet. They burrow below the frost line during winter and occasionally use rodent burrows.

Greater short-horned lizards occupy sagebrush and shortgrass prairie, especially south-facing slopes, rocky rims of coulees, and shale outcrops. Common sagebrush lizard is associated with sagebrush habitat, but also lives in ponderosa pine and juniper along the Missouri River and in shortgrass prairies. The lizards seek refuge under rocks, in crevices at the base of trees, or in rodent burrows.

Painted turtles live in ponds and wetlands, and spiny softshell turtles and snapping turtles live in the Missouri and Musselshell Rivers. They lay their eggs on land, often spending winter months buried and inactive in soft mud. Spiny softshells dehydrate much faster than hardshell turtles, and they are rarely found far from water. Nesting occurs in sand or gravel, usually 100 yards or less from water. Snapping turtles are omnivores that live in large rivers, lakes, ponds, and marshes. They dehydrate more rapidly than most freshwater turtles, so are vulnerable to high temperatures and low humidity. They overwinter under cutbanks, submerged logjams, or in the bottom mud of larger rivers or marshes.

Western hognose snake and prairie rattlesnake use burrows, dens, and tunnels dug by prairie dogs and pocket gophers for cover and as places to search for food. Rock outcrops in grassland areas provide important cover and basking sites. Western hognose snakes like well-drained, sandy soils, so are often seen along exposed riverbanks, sandstone outcroppings, and old riverbeds. Eastern yellow-bellied racers use open habitats such as prairie, sagebrush, and badlands. They overwinter in mammal burrows, rock crevices, and sandbanks, alongside garter snakes, rattlesnakes, or gopher snakes. Milksnakes inhabit grasslands and spend most of the day in burrows around sandstone outcroppings, riparian zones, cedar–juniper hillsides, and margins of agricultural lands.