Ambystoma tigrinum
tiger salamander

This mole salamander is the largest land dwelling salamander in North America. It also has the greatest range of any other North American salamander, spreading in range from southeastern Alaska east to the southern part of Labrador, and south throughout all of the United States down to the southern edge of the Mexican Plateau (Indiviglio 1997).

Fully metamorphosed adults lead a terrestrial existance and, depending upon where in the country they are found, some may inhabit forests, grasslands, or marshy areas (Petranka 1998). Tiger salamanders are less dependent on the forest than most other Ambystomids. One general requirement seems to be soil in which they are able to burrow or in which the burrow of other species of other animals might be utilized (Petranka1998). While they are well suited for terrestrial existence in terms of their skin consistency and thickness, they do need to be able to burrow underground in order to seek the proper humidity levels. Another requirement is that they live close enough for permanent access to ponds and othe small waters for their breeding. During dry periods, large numbers of tiger salamanders have been found lying in piles beneath suitable cover or underground (Indiviglio 1997).

Adult Length 17-33 cm.

The adult tiger salamander is a thick-bodied creature generally with yellow blotches or spots against a black background. Once in a while there will be one with blotches that are tan or olive green in color. The spots or blotches are never in any set shape, size or position. Actually you may even be able to tell its origin by the color and pattern of the background and/or spots (Indiviglio 1997). A. tigrinum has a rather large head and a broad rounded snout. Their eyes are round. The belly is usually yellowish or olive with invading dark pigment. It has about 12-13 coastal grooves (Harding 1997). Males tend to be proportionally longer, with a more compressed tail and longer stalkier hind legs than the females. During the breeding season the males have a swollen vent area. The larvae have a yellowish green or olive body with the dark blotches and a stripe along each side. They also have a whitish belly. As they grow, specimens tend to be grayish or greenish in color, and within a few weeks they start to show yellow or tan spots and gradually merge into the patterns of the adult bodies (Harding 1997).

Eggs are laid in small pools and hatch within a time period of 19 to 50 days. The larvae remain in the pond until they turn into adults at 2.5 to 5 months of age. Sometimes, adult tiger salamanders remain in the aquatic larval form for their entire lives.

Aquatic adult tiger salamanders live up to 25 years in captivity. Normal adults have reached ages of 16 years.

Adult Tiger Salamanders live underground for most of the year and usually dig their own burrows, unlike other species that use burrows of other animals. They have been found over 60 cm below the surface (Harding 1997). This allows them to escape the temperature extremes on the surface and may explain why they have such a wide array of habitat types.

The tiger salamander's food source consists of worms, snails, insects, and slugs in the wild; while captive specimens rely on smaller salamanders, frogs, newborn mice, and baby snakes. Tiger salamanders in the wild also tend to eat the same thing as captives, if opportunity presents itself (Indviviglio 1997). The larvae begin feeding on small crustaceans and insect larvae and once grown, they will feast on tadpoles and smaller salamander larvae and even small fish (Harding 1997).

Tiger salamanders are eaten by badgers, snakes, bobcats, and owls. Larvae are eaten by aquatic insects, the larvae of other salamanders, and snakes.

They are efficient predators in their aqautic and subterranean environment, and their prey includes some insect pests.

The larvae are sometimes considered a nuisance in fish hatcheries. Large larvae will feed on very small fish, but their main effect might be to act as competitors with the fish. As the fish grow larger they can turn the tables and feed on the salamander larvae.

In some places Ambystoma tigrinum are captured and sold for fish bait (Harding 1997).

Populations in the southeastern U.S. have been affected by deforestation and loss of wetland habitats and appear to be declining in many areas. According to studies in the Colorado Rockies done by Harte and Hoffman, acid rain may be responsible for this. Other studies indicate that it might not have anything to do with it (Petranka 1998). Other threats for these salamanders are being hit by cars and polluting of their ponds and habitats.