Jefferson salamander

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Ambystoma jeffersonianum

Type: amphibian

Status: special_concern

Species Guide

Jefferson salamander

Ambystoma jeffersonianum

Species Type: amphibian

Conservation Status: special_concern

IDENTIFICATION

4 1/4” – 8 1/4”.  Ground color of this slender salamander is dark brown or gray; the underside is lighter than the sides.  The limbs and lower sides of the body are usually marked by tiny bluish-gray speckles.  These speckles are bright on young individuals, but fade with age.  This species closely resembles the blue-spotted salamander, but has a gray area around the vent while the blue-spotted has a black area around the vent.  Also, the snout is wider and extends further forward than in the blue-spotted salamander.

Distribution & Habitat

Jefferson salamanders are secretive, breeding in woodland vernal ponds and living underground in upland deciduous forests featuring rocky outcrops and an abundance of rotting logs and stumps up to one-half mile from their breeding pool.  They may be found when looking under logs and other cover objects, but generally, finding a Jefferson salamander is a rare event except for breeding nights in late winter and early spring.

Diet

The diet of adult Jefferson salamanders includes worms, insects, snails and slugs. Salamander larvae feed on plankton, and aquatic insects.

Life Cycle

Migration to the breeding pools is the earliest for any of the mole salamanders occurring in northern New Jersey, sometimes taking place on rainy nights with the ground only partially thawed and ice still on the pools.  At the pools, males and females locate each other by chemical cues and the male courts the female with snout rubbing, clasping, mutual swimming and tail waving.  If the female is receptive, the male drops spermatophores and the female picks up sperm in her cloaca.

A few days after mating, the female lays up to 250 eggs in small clusters of 12-75 eggs attached to vegetation near the water surface.  The masses are clear, have a loose consistency, and are difficult to see.  They are tubular when attached to twigs and rirregular when attached to soft vegetation.  Embryos develop quickly and hatch within 4-6 weeks.

Young larvae hide within the leaf litter and are fiercely predatory on all manner of invertebrates and even other salamanders.  As they grow, they feed in the open water of the pool where they may be observed at night and on sunny days hunting near the water surface.  They are preyed upon primarily by predatory insects.  Larvae complete development in 2 to 4 months and leave the pool for small mammal burrows in the forest.  Sexual maturity is reached in three years.  Their life span may be another three years in nature.

Current Threats, Status, and Conservation

This species exhibits strong fidelity to its breeding ponds and has suffered from degraded water quality in these ponds. Our expanding network of roads has negatively impacted this species by impeding salamander movements into breeding ponds and increasing the incidence of roadside mortality.

The primary threats facing Jefferson salamanders in New Jersey are the loss, alteration, and degradation of quality habitat. Specialized habitat requirements and strong fidelity to breeding ponds render these salamanders vulnerable to habitat loss. In addition, restricted range and isolated populations hinder their ability to recover from localized extirpations or declines.  An expanding network of roads fragmenting forests may impede salamander movements to breeding ponds or result in road mortality of migrating adults and dispersing juveniles. These salamanders are sensitive to water quality and may therefore be negatively affected by runoff, insecticide spraying, and other pollutants.

Jefferson salamander locales, including breeding ponds and terrestrial habitats, should be protected from development, habitat degradation, and the reduction of water quality. In addition, mosquito control efforts, including insecticide spraying, should be restricted in the areas these salamanders occur.

References

Text written by Brian Henderson in 2011.

Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Amphibia
  • Order: Caudata
  • Family: Ambystomatidae
  • Genus: Ambystoma
  • Species: A. jeffersonianum