Jefferson's Salamander Ambystoma jeffersonianum

Adult male from Ripley County

Identification

These are fairly large salamanders with long toes, elongated snouts, and heavily keeled tails. Jefferson's Salamanders are gray or dark gray in coloration with some lighter speckling dorsolaterally and light gray ventral coloration. Juveniles are similar to adults with more prominent blue or white dorsal speckling. Adults can reach 7-8 in (17-20 cm) in total length. Jefferson's Salamanders deposit eggs in elongated, globular masses attached to sticks and vegetation. These masses are much looser and more gelatinous compared to those of the Spotted Salamander (Ambystoma maculatum), which often occurs in the same ponds. Jefferson's Salamanders have a pond-type larva with a tall tail fin and bushy external gills. Small larvae are green or brown with some yellow pigmentation on the neck, head, and dorsal fin. Older larvae are gray with heavily marked tail fins and have plain bellies (Petranka 1998).

Egg mass from Jennings County
Adult female from Jennings County
Adult female from Kentucky

Blue-Spotted Salamanders (Ambystoma laterale) are similar in appearance but have more pronounced and profuse blue spots dorsally and laterally. The snout and toes of Blue-Spotted Salamanders are not as elongate as those of Jefferson's Salamanders and the tail is more rounded. The range of these two species meets in the central part of the state, where differentiating the two can be difficult. Both Streamside Salamanders (Ambystoma barbouri) and Small-Mouthed Salamanders (Ambystoma texanum) are similar to this species, but they have a shorter snout and are generally more robust with a more lichenate pattern dorsally. These two species are sympatric with Jefferson's Salamanders in southern Indiana, but Streamside Salamanders breed in streams, whereas Jefferson's Salamanders breed in ponds. Small-Mouthed Salamanders rarely share the same ponds as Jefferson's Salamanders, as the former favors lowland habitat while the latter is found almost exclusively in uplands. Most confusingly, some representatives of the lineage of unisexual Ambsytoma contain genomes from Jefferson's Salamanders can be difficult to differentiate morphologically.

Ecology and Conservation

Jefferson's Salamanders are typically found in hilly, wooded uplands and in upland flatwoods (southeastern Indiana). They are absent from bottomland habitat, but floodplain habitat may be utilized where it's adjacent to uplands. Ridgetop vernal pools are the favored breeding site throughout most of southern Indiana. Like other members of the family Ambystomatidae, adults of these salamanders are rarely observed outside of the breeding season. Larval Jefferson's Salamanders feed on small aquatic invertebrates while adults feed on a variety of terrestrial invertebrates.

Vernal pool from Jefferson County
Ridgetop pond from south-central Indiana
Vernal pool from Jennings County

Breeding sites for this species are almost exclusively fishless. Movement to ponds may take place during cool rainy weather throughout October and November or during December and January. Males arrive first at breeding sites and deposit spermataphores. Females later arrive and deposit eggs along sticks and debris. Where the two species are found together, Jefferson's Salamanders breed earlier than Spotted Salamanders (Ambystoma maculatum). They likely metamorphose in the late spring and early summer.

No particular threats are known to Jefferson's Salamander populations in the state, although early, warm winter weather followed by severe cold spells does occasionally cause substantial adult mortality during the breeding season. Global climate change could potentially exacerbate these periodic die offs with more extreme and variable weather.

Distribution

Jefferson's Salamanders occur throughout the northeastern United States from eastern Illinois (historically), Indiana, and Kentucky northeast into New Hampshire. Jefferson's Salamanders are found throughout the hills and uplands of southern Indiana and are absent from the bottomlands of southwestern Indiana. In central and northern Indiana, unisexual Ambystoma are more common.

Taxonomy

There are no recognized subspecies of the Jefferson's Salamander (Ambystoma jeffersonianum). It belongs to the family Ambystomatidae, which is represented in Indiana by eight species (plus the unisexual Ambystoma)--the most of any state!

Literature Cited

Conant, R. and J. T . Collins. 1998. Reptiles and Amphibians of Eastern and Central North America. Third Edition, Expanded. Houghton Mifflin, New York, NY.

Minton, S. A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Science, Indianapolis, IN.

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

Distribution Map
Distribution map of Jefferson's Salamander (Ambystoma jeffersonianum)
Photographs