Eastern tiger salamander

Eastern tiger salamander is a large, terrestrial, mole salamander. It is the largest terrestrial salamander in Minnesota. Only the mudpuppy (Necturus maculosus), an aquatic salamander, is larger. Adults are usually 6¾″ to 8⅝″ in length but they can be much larger. In 1994 one was found in Minnesota that was 13¾″ long. Males tend to be larger than females.

The body is stout with four well-developed limbs that project sidewards. The trunk is cylindrical. There are 11 to 14 prominent vertical depressions (costal grooves) between the forelimbs and the ventral area. The skin is soft, moist, and black with dull yellow, irregularly sized and spaced blotches. The belly is black with yellow splotches. The color pattern is highly variable and may be geographically distinct. Juveniles are mostly black with small yellow spots. As the salamander ages, the spots usually become larger and fuse together, increasingly obscuring the black background. The tail is long and tapered.

The head is large, short and wide with a broad, rounded snout. The lower lip and throat are usually yellow. The eyes are small, round, and protruding.

The legs are short and stout, with broad feet. The hind legs have five toes. The fore legs have four toes. The toes are short, broad at the base, and tapered to the tip.

The larvae have a paler background color, dark splotches, dark lateral stripes, and a whitish belly. They have long, filamentous, external gills and a wide tail fin (caudal fin) that extends from just behind the head on the upper side to the ventral area on the underside, wrapping around the tail.

6¾″ to 8⅝″

Spotted salamander (Ambystoma maculatum) background color is gray. The spots are more regularly rounded and occur in two irregular rows. The spots on the head may be orange. The belly is gray with no spots. It has been recorded only in Pine and Carlton Counties.

Prairies, agricultural fields, woodlands, and residential areas, all near permanent or semi-permanent bodies of water.

Eastern tiger salamander, like all salamanders, is rarely encountered. It spends the day in a burrow, usually one that it has dug itself, sometimes in one dug by rodent, shrew, or other animal. The burrow may be up to 40″ deep. The salamander comes out at night to feed. It is sometimes encountered by humans in window wells and damp basements. It is sometimes seen aboveground at night during and after a rainfall, moving to or from a breeding pond, during the spring breeding and migration season.

The skin exudes a milky, unpleasant tasting liquid in response to a predator.

16 years

Breeding takes place in the early spring, often before the ice has cleared from the surface of the pond. Adults migrate up to about 330 yards to a pond or other suitable body of water.

To initiate breeding, the male will nudge a female to separate it from other salamanders. It then deposits a sperm capsule on the pond bottom, the female picks up the sperm capsule, and the process is repeated. At night, usually 24 to 48 hours after fertilization, the female lays fragile masses of up to 100 eggs and attaches them to twigs, grass stems, and decayed leaves on the bottom of the pond. She may lay up to 1,000 eggs.

The eggs hatch in 2 to 5 weeks, depending on the temperature. Larvae may metamorphose into sexually mature adults in their first or second summer, or they may become sexually mature without metamorphosis.

Adults overwinter in burrows or under logs or other debris. Their lifespan is about 16 years in the wild, up to 25 years in captivity.

Small crustaceans and insect larvae, when young; also other salamander and small fish when older. Some are also cannibalistic, feeding on other salamander larvae.

Earthworms, insects, snails, and slugs, and any other small animal that can be captured and swallowed.