Adult Description: As adults, Western Tiger Salamanders are terrestrial. Western Tiger Salamanders range from 6–9 inches (15–22 cm) in total length, and have five toes on their hind feet, rounded heads, cylindrical bodies, small protruding eyes, and smooth, moist skin. Adult Western Tiger Salamanders can be highly variable in color and pattern. This includes individuals with a dark black background with large, bold yellow bars extending from their underside up to their back, to individuals with an olive green to gray background with thin black markings.
Larval Description: As juveniles, Western Tiger Salamanders are aquatic and are typically yellow to brown in coloration with little visible pattern or markings and have three pairs of external, feather-like gills used for respiration. As individuals age and begin metamorphosis, these gills begin to shrink in size and markings and patterns begin to develop on the body. Additionally, the tail is enlarged with a thin, membranous fin extending from the tail to aid in swimming, which shrinks as individuals are undergoing metamorphosis.
Habitat: Western Tiger Salamanders inhabit moist areas near wetlands and prairies, and often utilize mammal burrows, such as abandoned prairie dog burrows. They may also occur near homes, such as in basements or root cellars. Breeding habitat primarily consists of wetlands or ponds that lack large fish.
Natural History: Adult salamanders are infrequently encountered as most adult movement occurs in the early spring while they are moving to and from breeding habitats during and shortly after heavy rains. Individuals seek shelter underground throughout the summer and winter and are typically active from April–September. Salamanders are typically nocturnal and are generalist predators feeding mostly on invertebrates, but also on small vertebrates. When disturbed, individuals can discharge a bitter-tasting, milky slime. Breeding typically occurs in the early spring, and the timing is largely determined by temperature and rainfall. Courtship can be quite elaborate and involve aggressive behaviors between males and females. The male guides the female to a spermatophore that he has deposited, and the female picks it up with her cloaca, fertilizing her eggs. Adult females can lay up to 1,000 eggs in small clusters typically attached to aquatic vegetation or woody debris. After a few weeks, eggs hatch into larvae, which grow throughout the summer, and most complete metamorphosis by July or August. On occasion, larval salamanders can demonstrate neoteny, where individuals become sexually mature while retaining larval characteristics and never leave water.
Species Distribution: Western Tiger Salamanders occupy a large region containing most of the Great Plains and Rocky Mountains and are among the most widely distributed salamander in North America.
South Dakota Distribution: Western Tiger Salamanders are distributed across much of South Dakota, except the southeastern corner of the state.
South Dakota Status: This species is not monitored by South Dakota Game, Fish and Parks.
Remarks: Research into the species boundary between the Western Tiger Salamander and Eastern Tiger Salamander is needed. Color and pattern variation and the potential to hybridize further complicates defining the exact boundary of these species in southeastern South Dakota. As larvae, these salamanders are often called a “mudpuppy” or “waterdog” and may appear similar to the Mudpuppy (Necturus maculosus), a much different salamander that is permanently aquatic and have four toes on their hind feet. Larval tiger salamanders are often sold as fishing bait, and as a result Western Tiger Salamanders have been widely introduced to new sites by anglers.