01 April 2011

Flipping Rocks And Logs

During the past several weeks, I've done a lot of rock, log, and moss flipping looking for salamanders. Lee Casebere came up to northern Indiana on 13 March 2011 to search for early Four-toed Salamanders (Hemidactylium scutatum), and Scott Holaday and I joined him in this effort.

Unfortunately, no Four-toed Salamanders could be found... the photograph above is from September 2003 in Michigan. We knew that it was a bit early to find salamanders, but we were looking more for habitat than anything else. The habitat that we were searching for was vernal pool with mosses at the waterline. Four-toed Salamanders also are found in bogs, near springs, and in swamps in scattered areas throughout much of the eastern United States. Mosses, especially fern moss (Thuidium spp.) and sphagnum (Sphagnum spp.), are important for this species because females lay eggs within and underneath them to keep the eggs moist and to allow the newly hatched salamanders to drop into the water directly beneath. Four-toed Salamanders can be distinguished by the black-spotted white belly and the tail that is constricted at the point where it meets the body.

The following week, I joined Lee in southeast Indiana to search for Four-toed Salamanders and Two-lined Salamanders (Eurycea cirrigera).

Again, we struck out, sort of. We weren't able to find any Four-toed Salamanders or Two-lined Salamanders on this trip, but as you will see below, we did have a productive day, finding five other salamander species. The Two-lined Salamander pictured above was found in west-central Indiana on 2 April 2011. Lee had told me that they hang out under flat rocks in moving streams, and he was exactly right, as Bill Ringer and I found numerous individuals on our 2 April 2011 excursion. The wide, dark stripe down each side of the often yellowish body identify this species as a Two-lined Salamander. The range of this species in the United States includes nearly all of the states east of the Mississippi River. A Two-lined Salamander spends its first year as an entirely aquatic larva, so this species cannot survive in creeks that completely dry up late in the year.

On the other end of the spectrum is the Redback Salamander (Plethodon cinereus), which is entirely terrestrial. The individual shown above was seen during my 13 March 2011 trip with Lee to southeastern Indiana. You would think that a species with "redback" in the common name could be identified by its red back, like the one shown above, but there is also a color morph that has a dark back and that looks very similar to the much less common Ravine Salamander (Plethodon richmondi). Redback Salamanders are known mostly from the northern states in the eastern half of the United States, but their range extends as far south as North Carolina along the East Coast. Redback Salamanders are found in forests and woodlands.

Northern Dusky Salamanders (Desmognathus fuscus fuscus), shown above, are dark colored and somewhat nondescript. In Indiana, they are only known from the southeastern quarter of the state, but their range within the United States includes most states east of the Mississippi River, plus Arkansas and Louisiana. This species can be found in springs, creeks, and streams, and Lee and I found several under rocks in flowing water on 13 March 2011.

The amphibian above just screams "if you eat me, you will pay." This is the eft stage of the Eastern Newt (Notophthalmus viridescens), and like many other things in nature that are brightly red or orange colored, the Eastern Newt is highly toxic. In fact, the skin of both the eft and adult stage of this species contains one of the most lethal toxins known to man, tetrodotoxin. The concentration of this chemical is much greater in the eft stage than in the adult stage. The Eastern Newt has three life stages... the aquatic larval stage, the entirely terrestrial eft stage, and the aquatic adult stage. Eastern Newts are found in forests with nearly permanent pools that accomodate all three life stages; they are known from most of the eastern half of the United States (to as far west as Texas).

The fourth species that Lee and I saw on 13 March 2011 was the Marbled Salamander (Ambystoma opacum), shown above and below. As the common name implies, the skin of this species has a marbled appearance. This species is found in forests, including floodplains, flatwoods, and uplands. It is known from southern New England to Texas but has a primarily southern distribution. This is likely due in part to the fact that, unlike many other salamanders, Marbled Salamanders breed in the fall and overwinter as larvae. This gives them a competitive advantage and allows the larvae to feed on larvae of other salamanders in the spring. However, a species that overwinters in the larval stage is not well adapted to harsh northern winters.

This one sure looks happy, doesn't it?

Finally, one of the most attractive salamanders in my opinion is the Spotted Salamander (Ambystoma maculatum), shown above. There is no question about where the common name of this species came from! Like many of the other species in this post, Spotted Salamanders are known from much of the eastern half of the United States, to as far west as Texas. Its habitat requirement is forest with ponds, such as flatwoods. According to Minton (2001), "When injured or roughly handled, these salamanders exude a white fluid from skin glands, particularly those on the tail. Upon touching some to my tongue, I noticed an astringent taste followed by slight tingling and numbness." Can't say that I would have tried tasting the exuded fluid had I seen it.

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