DESCRIPTION: As Arizona’s only salamander, this species is unmistakable. Adult, terrestrial tiger salamanders grow to as much as 13.6 inches total length and 6.5 inches snout-vent length. They exhibit varying combinations of dorsal light and dark spots, bars, or reticulation. The Arizona tiger salamander (A. m. nebulosum), known from the Mogollon Rim area and the Colorado Plateau, is typically a dark grayish to olive salamander with irregularly-shaped yellow to olive spots and blotches (but see photo above). The barred tiger salamander (A. m. mavortium), which has been widely introduced by anglers and bait collectors to much of southeastern Arizona and is sometimes encountered elsewhere in southern Arizona, has large, distinct yellowish bars or spots on a dark background. The Sonoran tiger salamander (A. m. stebbinsi), an endangered subspecies from the San Rafael Valley, possesses a unique reticulate pattern on a dark background, but many are indistinguishable from the barred salamander.  Larvae and gilled adults, called branchiates or neotenes, are aquatic, olive-gray, and possess three gills on each side of the head.  Early in development, larval salamanders lack legs.  Arizona and barred branchiate salamanders, and very rarely, Sonoran tiger branchiates, may develop into large (up to 15 inches total length), big-headed, cannibalistic morphs.

DISTRIBUTION:  Tiger salamanders can be found throughout much of Arizona outside of the lower and more arid southwestern and western deserts.  They are widely used as fish bait, and so may occasionally be encountered as an introduction outside of their mapped range.   

HABITAT: Tiger salamanders breed in the still or sluggish waters of ponds, cattle tanks, backwaters, and lakes; often in open country.  They breed in permanent or ephemeral wetlands, but the former often contain predators (e.g. fishes) that preclude or limit recruitment. When not breeding, terrestrial adults can be found in the uplands, often on roads at night during storms, sometimes as far as 2-3 miles from the breeding pond.  The Sonoran tiger salamander is found in the grasslands of the San Rafael Valley and adjacent foothills of the Huachuca and Patagonia mountains. Arizona tiger salamanders occur in coniferous forests, chaparral, and high grasslands; and barred salamanders occur primarily in desert scrub and semi-desert grassland.

BEHAVIOR:  Tiger salamanders have a complex life history that increases the likelihood of population persistence despite the dynamic nature of breeding habitats.  During drought, ponds may not stay wet long enough to allow for metamorphosis of larvae, but terrestrial adults remain in the uplands to breed in subsequent years.  In wet cycles, breeding will occur by both terrestrial and branchiate adults, and if environmental disaster strikes in the uplands, depleting numbers of terrestrial adults, reproduction by aquatic branchiates can still maintain the population.  An iridovirus, likely introduced to Arizona with bait salamanders, sport fish, or by other means, frequently decimates salamander populations.

DIET: Larvae and branchiates feed on a wide variety of invertebrates.  Cannabilistic morphs eat larger prey and may preferentially eat their own kind.  Terrestrial adults feed on a variety of surface and subterranean invertebrates.  Adults and large larvae will eat vertebrates, as well, including tadpoles, lizards, small snakes, and mice.

REPRODUCTION:  Breeding occurs from mid-winter into late spring; and rarely in late summer.  Terrestrial adults typically return to their natal ponds to breed.  Females lay 200-2,000 eggs individually or in small groups attached to sticks, aquatic vegetation, debris, or on the substrate.  Eggs take 14-50 days to hatch, depending on water temperature.  Larvae can metamorphose in as little as 2 months, but growth varies with a number of factors.  The larval period is typically longer than 2 months, and some overwinter.  

Lannoo, M.J., and C.A. Phillips. 2005. Ambystoma tigrinum (Green, 1825). Pages 636-639 in M.J. Lannoo (ed), Amphibian Declines: The Conservation Status of United States Species.  University of California Press, Berkeley.

Petranka, J.W. 1998. Salamanders of the United States and Canada. Smithsonian Institution Press, Washington D.C.

U.S. Fish and Wildlife Service. 2002. Sonora tiger salamander (Ambystoma tigrinum stebbinsi) recovery plan. U.S. Fish and Wildlife Service, Region 2, Albuquerque, NM.