Eastern Newt
Notophthalmus viridescens
Summary: Newts occur sporadically in the Chicago region, with most records in the more extensive woodlands. Recent records are available for Cook, Lake, and DuPage Counties in Illinois, and Lake and Porter Counties in Indiana.
Description: A small salamander, up to a little over 4 inches (11cm) in total length. Aquatic or semi-aquatic adults are smooth-skinned with a distinct tail fin, olive green to yellow-brown above with fine black speckling. The underside is yellow with more profuse and distinct black dots. The terrestrial eft stage has rougher and darker skin, usually rusty brown.
Distribution and Status: Newts occur at scattered localities around the region. Although the number of populations is not large, individuals tend to be relatively common where they do occur. The best known populations are in the Palos-Sag Valley area and in various parts of the Indiana Dunes, and at two DuPage County sites. The species also occurs in at least one northwestern Lake County, Illinois, location with historical reports in the southeast of the county. A Kane County population is believed to have been destroyed by recent development. A Lake County Indiana site first reported by Victor Shelford (1913) still harbors a small population.
Habitat: Most of the known localities are associated with extensive wooded groves which include permanent wetlands with dense aquatic vegetation. An exception is one of the two Lake County Indiana localities, a near-lakeshore ridge and swale site with relatively open sand savanna. In other parts of the U.S. vegetated lake margins are utilized.
Phenology: In Cook County, for seven consecutive years we caught newts moving toward ponds in March and early April (Mierzwa, 1998). Although we never captured more than 13 individuals on land in any year, adults were common in ponds so some must overwinter there. Cortwright (1998) noted a similar situation in Indiana.
Single eggs are attached to submerged vegetation. Gilled larvae reportedly leave the ponds in late summer (Phillips et al. 1999). The terrestrial eft stage has been confirmed in Cook and DuPage Counties, but little else is known about the land form in this area. Some reports of surface activity by efts have been in August. In other places the eft stage may last for two to seven years before the newt returns to the water to breed (Forester and Lykens, 1991).
In general, this is one of the least studied amphibians in the region. Considering that the newt is relatively common and easily observed at a handful of well-known sites, and that a wealth of literature is available from other parts of the U.S., that is perhaps surprising. More detailed local studies should be encouraged.
Literature Cited
Cortwright, S. A. 1998. Ten-to-eleven-year population trends of two pond-breeding amphibian species, red-spotted newts and green frogs. Pp. 61-71 in: M. J. Lannoo (ed.), Status and Conservation of Midwestern Amphibians. University of Iowa Press. xviii+507p.
Forester, D. C., and D. V. Lykens. 1991. Age structure in a population of red-spotted newts from the Allegheny Plateau of Maryland. Journal of Herpetology 25:373-376.
Mierzwa, K. S. 1998. Status of northeastern Illinois amphibians. Pp. 115-124 in: M. J. Lannoo (ed.), Status and Conservation of Midwestern Amphibians. University of Iowa Press. xviii+507p.
Phillips, C.A., R. A. Brandon, and E. O. Moll. 1999. Field Guide to Amphibians and Reptiles of Illinois. Illinois Natural History Survey Manual 8. 282p.
Shelford, V. E. 1913. Animal Communities in Temperate America, as Illustrated in the Chicago Region. University of Chicago Press. xiii+368p.
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| Updated: October 9, 2007
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