Eastern Tiger Salamander
Pictured above: This adult Tiger Salamander is owned by the Hixon Forest Nature Center
Description: As adults, Tiger Salamanders are the largest terrestrial salamander in Wisconsin, reaching lengths of 7 to 13 inches. They are black with a large degree of yellow bands or mottling and yellow eyes that protrude from their heads. Tiger Salamander larvae are generally grayish with tan or black mottling. They typically have large, frilly external gills and, depending on the stage of development, they can have two or all four appendages. As larvae, Tiger Salamanders have broad heads designed for consuming prey. Tiger Salamanders are members of the family Ambystomatidae
Habitat/Ecology: Tiger Salamanders are probably the most prolific of Wisconsin's terrestrial salamanders. They can be found in a variety of habitats adjacent to wetlands, including constructed farm ponds. In Minnesota, I have found larvae in farm ponds that were completely surrounded by crops and it seemed impossible to find a habitat suitable for a terrestrial salamander anywhere. Adults spend the majority of their time underground, either in self-excavated burrows, fissures, or under moist debris. Adults are seldom found in the open unless breeding. The breeding season is generally from late March to May and larvae usually begin metamorphosing by late July to August. Adults have been reported to eat anything they can overpower from earthworms to small mammals.
Remarks: Tiger Salamanders seem to be able to withstand a fair degree of human disturbance. I have encountered them in natural wetlands, farm ponds, and even wetlands next to apartment complexes in Stoughton, WI. Their larvae are voracious predators and research has been performed on their role as the top predators in fishless wetlands. In captivity, I have witnessed a six inch individual consume two to four 3" minnows in a single sitting. It is interesting to note that a cannibalistic variation of this salamander occasionally exists in ponds where they are over-abundant, however, it has not yet been described in Wisconsin that I am aware of.
Within Wisconsin, it may be easy to confuse adult Tiger Salamanders with adult Spotted Salamanders. However, Spotted Salamanders have distinct, isolated spots, whereas the Tiger Salamanders' spots seem to be more like blotches or bands in a random orientation. Also, Spotted Salamanders are reported to be found more so in the northern and eastern portions of the state.
Although Christoffel et al. (2001) list Tiger Salamanders as existing in La Crosse County, I have not witnessed adult Tiger Salamanders nor their larvae within the La Crosse area. However, I have found them in nearby Houston and Winona Counties (Minnesota) and I believe that they exist here as well. It is not uncommon for them to be found in the window-wells of homes near a water source of some kind. If anyone has found salamanders of any kind within the La Crosse area, I would love to hear about it.
Pictured above: As larvae, Tiger Salamanders look much different than as adults. Larvae are completely aquatic, like frog tadpoles, however, they have large external gills (above right and left, bottom left). Also unlike tadpoles, larval salamanders are highly predacious on both aquatic invertebrates and vertebrates. Adults generally have more yellow coloration than pictured above (bottom right).