Eastern tiger salamander

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Ambystoma tigrinum tigrinum

Type: amphibian

Status: endangered

Species Guide

Eastern tiger salamander

Ambystoma tigrinum tigrinum

Species Type: amphibian

Conservation Status: endangered

Identification

The Eastern Tiger Salamander is the largest salamander in New Jersey (7-8.25”). The ground color is dull black to dark brown; the underside is blotchy olive-yellow.

Tiger salamanders belong to a group of known as mole salamanders, which possess broad heads with blunt, rounded snouts that help them to burrow underground. Males have a longer tail and longer, stouter hind legs than the female.

Distribution & Habitat

Their current range is limited to Cape May and southern Atlantic and southeastern Cumberland counties. Cape May County serves as a population stronghold.

Tiger salamanders require both upland and wetland habitats that contain suitable breeding ponds, forests, and soil types appropriate for burrowing. These salamanders reside in underground tunnels or beneath logs for much of the year. Loamy sand and sandy loam soils are preferred for burrowing.

As natural breeding ponds have been lost, old gravel pits and farm ponds have come to serve as breeding sites for the eastern tiger salamander. These ponds must contain clean water free of sediment. Tiger salamanders require pools that contain water long enough to allow for metamorphosis, but dry up late in the summer. This cycle prevents the establishment of predatory fish populations. Consequently, breeding ponds are typically only 2 to 4 ft. deep.

Vegetation around and within the pond, provide cover for salamanders. Ponds may have gravel, mud, sand, or clay (bottoms) and pH levels ranging from 3.5 to 7.9.

Diet

Adult tiger salamanders are opportunistic feeders. They feed on a variety of invertebrates such as insects and their larvae, worms, and spiders. Tiger salamander larvae feed on fairy shrimp, plankton and other small invertebrates.

Life Cycle

Mild temperatures from late October to March trigger the nocturnal movement of adult tiger salamanders to their breeding ponds. They exhibit strong site fidelity, and most return to breed in the same ponds from which they metamorphosed. Tiger salamanders are able to breed to three years of age. Individual adults may be able to breed only every two years.

Photo by Bob Cunningham.

Following mating, the female deposits egg masses within the water. Eggs are typically laid from January to mid-March. Clutch sizes range from 5 to 122 eggs and average about 50 eggs per mass. One female may lay a total of 250 to 350 eggs in five to eight different masses. The eggs are attached to twigs, stems, or rooted vegetation within the water. The eggs are deposited in areas of the pond that are less susceptible to the elements but are still warmed by sunlight.

Eggs hatch from late March to April when water temperatures exceed 48°F. The larvae, which have feather-like gills, measure 0.5 to 0.7” at hatching. They transform in 75 to 118 days, depending on temperature and weather conditions. Most juveniles emerge during July. From the ponds, they disperse to underground tunnels or burrows.

Following breeding, adults may remain within ponds or move to uplands to seek cover in burrows or beneath stumps or logs. They may excavate their own tunnels or use those of small mammals. Tiger salamanders occupy a small home range and remain near larval ponds outside of the breeding season.

Current Threats, Status, and Conservation

Habitat loss and the pollution of breeding ponds led to declines of tiger salamander populations in New Jersey. By the mid-1970s, the known historic breeding sites had been roughly halved. Currently, the status of the tiger salamander population in New Jersey remains endangered. Population stability varies by site.

The loss and degradation of vernal ponds and wooded uplands are the main threats to tiger salamanders in New Jersey. Illegal dumping, along with filling and pollution of vernal ponds, have destroyed or degraded many breeding sites. Wetland disturbance favors the growth of invasive plant species that dominate the native plants tiger salamanders use to anchor their egg masses. Pollution from insecticides, runoff, and fertilizers may kill eggs and larvae or render ponds uninhabitable. Development of upland forests destroys critical habitat for non-breeding salamanders. Salamanders are also highly at risk of road mortality during migration to and from breeding ponds.

Surveys must continue to monitor population trends and habitat conditions. Protection or acquisition of breeding ponds and surrounding habitats is also important. Tiger salamanders have been saved from localized extinction by their ability to use man-made pools for breeding. As a result, management efforts work to create additional habitat for this species.

References

Text derived from the book, Endangered and Threatened Wildlife of New Jersey. 2003. Originally written by Sherry Liguori and Kathleen Clark. Edited and updated by Brian Henderson.

Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Amphibia
  • Order: Caudata
  • Family: Ambystomatidae
  • Genus: Ambystoma
  • Species: Ambystoma tigrinum tigrinum