Smallmouth Salamander
Ambystoma texanum
Summary: Enters the southwest corner of the region via the Illinois River Valley. There is a recent report from southwestern Will County, and historical records from Grundy County and near Kankakee. In LaSalle County, the species is found in floodplain forest and breeds in oxbow ponds. This species is abundant in central Illinois, but is at the edge of its range in this region.
Description: A medium sized salamander, 4.0 to 7.0 inches (10.0-17.8cm total length), with an elongated body form, a small head, and a short snout. In adults the head is only very slightly wider than the neck. Dark gray or brownish-gray above, with pale gray markings concentrated on the lower sides. The markings have been described as "lichen-like" by various authors (Minton, 1972).
Although superficially similar to the blue-spotted salamander, the larger size, more elongate body, distinctly smaller head and shorter limbs, and more subdued coloration set this species apart. The two species also do not overlap in distribution in this region.
Distribution and Status: This species barely enters the southern edge of the Chicago region, although it is a common salamander not far to the south. The smallmouth salamander is known from single specimens collected in southwestern Will County and near Kankakee. There is an undocumented but almost certainly valid 20+ year old report from Grundy County (Michael A. Morris, pers. comm.).
Swanson (1939) included the species on a list for the Jasper-Pulaski region. Minton (1972)questioned this record, and recent inventories there have not found it. However, given the presence of at least two other Kankakee River floodplain records, a historical presence upstream in Indiana cannot be conclusively ruled out.
The Will County record is the only recent one from within the area (Mauger, pers. comm.). I found this species with relative ease just outside the region in LaSalle County in 1997, and I suspect that further searches of appropriate habitat in the Illinois/Kankakee River valley will eventually locate additional specimens. All of the known reports are from floodplain situations.
Habitat: Most of my experience with this species is in St. Clair County, Illinois, and a few other counties well to the south. There, it is abundant in the more extensive floodplain forests where it breeds in shallow oxbow ponds. Most localities are in 40 to 90 year old second-growth woods; individuals were more easily located in the only old-growth site sampled, although this could be related to actual abundance or to the greater frequency of large fallen logs and a correspondingly higher incidence of places to search. Smallmouth salamanders also frequently strayed into adjacent fallow fields and open uplands. I have seen individual specimens in surprisingly open and degraded sites at a considerable distance from trees.
In LaSalle County the smallmouth salamander occurs in relatively young floodplain forest along the Illinois River, again breeding in oxbow ponds. Numerous potential localities along major rivers in Grundy, Will, and Kankakee Counties have never been thoroughly searched for this species.
Phenology: In southwestern Illinois, adults were most easily found in early spring. On one occasion very early in the year, I unearthed an adult female while digging to install drift fences prior to the onset of surface activity. The specimen was perhaps six inches below the surface. In that same region, eggs were deposited at the same time as those of tiger salamanders and western chorus frogs. No information is available for the Chicago region, but I would expect breeding to occur in March or very early April. Egg masses are relatively easy to locate in oxbow ponds, where they are attached to branches and twigs in the mid-water column. No information is available on larval development in the northern populations, but metamorphosis in early July is most probable. In extreme southern Illinois juveniles are easily found in and near dry pond basins in the fall.
Literature Cited
Minton, S. A., Jr. 1972. Amphibians and Reptiles of Indiana. Indiana Academy of Science Monograph No. 3. v+346p.
Swanson, P.L. 1939. Herpetological notes from Indiana. American Midland Naturalist 22:684-695.
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| Updated: October 9, 2007
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