More Information

Additional Information

Ambystoma tigrinumEastern Tiger Salamander(Also: Tiger Salamander)

By Alissa Wentz

Ge­o­graphic Range

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).

Habi­tat

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).

Phys­i­cal De­scrip­tion

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).

  • Average mass
    9.402 g
    0.33 oz
    AnAge
  • Average basal metabolic rate
    0.00196 W
    AnAge

De­vel­op­ment

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.

Re­pro­duc­tion

Am­bystoma tigrinum mi­grates to the breed­ing ponds in late win­ter or early spring, usu­ally after a warm rain that thaws out the ground's sur­face. Males tend to ar­rive ear­lier than the fe­males, prob­a­bly due to the fact that they live closer to the ponds dur­ing the win­ter months. Courtship hap­pens dur­ing the night where the males nudge and bump other sala­man­ders. Upon com­ing across a fe­male, the male will nudge her with his snout to get her away from the other males (Hard­ing 1997). Once away from the other males, the male walks under the fe­males chin, lead­ing her for­ward and then she nudges his tail and vent area. This be­hav­ior stim­u­lates the male to de­posit a sper­matophore. The fe­male moves her body so that the sper­matophore con­tacts her vent, thus al­low­ing her to take sperm into her cloaca. This be­hav­ioral move­ment con­tin­ues and pro­duces more sper­matophores. The com­pe­ti­tion for breed­ing is great in this species and some­times other males may in­terupt the court­ing pairs and re­places the sper­matophores with its own. The lay­ing of eggs oc­curs a night, usu­ally 24-48 hours after the courtship and in­sem­i­na­tion. They lay the eggs and at­tach them with twigs, grass stems and leaves that have de­cayed on the bot­tom floor of the pond. Each mass can ob­tain up to 100 eggs (Hard­ing 1997). When large enough, the masses can re­sem­ble that of a spot­ted sala­man­der but the mass of a tiger sala­man­der is less firm and is very frag­ile if han­dled. Each fe­male pro­duces any­thing from 100 to 1000 eggs per sea­son (Hard­ing 1997).

  • Average number of offspring
    37
    AnAge
  • Average time to hatching
    28 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    1460 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    1460 days
    AnAge

Lifes­pan/Longevity

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

Be­hav­ior

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.

Food Habits

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).

Pre­da­tion

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

Ecosys­tem Roles

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

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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.

Con­ser­va­tion Sta­tus

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.

Con­trib­u­tors

Alissa Wentz (au­thor), Michi­gan State Uni­ver­sity, James Hard­ing (ed­i­tor), Michi­gan State Uni­ver­sity.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

Ref­er­ences

Hard­ing, J. 1997. Am­phib­ians and Rep­tiles of the Great Lakes Re­gion. Ann Arbor, Mi: The Uni­ver­sity of Michi­gan Press.

In­di­viglio, F. 1997. Newts and Sala­man­ders. New York: Bar­ron's Ed­u­ca­tional Se­ries.

Pe­tranka, J. 1998. Sala­man­ders of the United States and Canada. Wash­ing­ton and Lon­don: Smith­son­ian In­sti­tu­tion Press.

Search

Navigation Links

Information
Pictures
Classification

Classification