Category Archives: Salamander

Spotted salamanders (guest post by Saunders Drukker)

I’m delighted again to share a guest blog post written by Saunders Drukker. Saunders is an Ecology and Biodiversity major at Sewanee (Class of 2017). 

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Spotted salamander, Ambystoma maculatum

In my last post on this blog I wrote about how winter was a time of increased activity for the forest dwelling amphibians that inhabit the Cumberland Plateau. Late February is the most active time of all. Towards the end of winter, when relatively warm rains begin to fall, amphibians of all types migrate through the hardwood forest of the Cumberland Plateau and set up temporary residence in water-filled depressions known as ephemeral ponds. Among the animals moving are animals like Upland Chorus Frogs Pseudacris ferriarum, Four Toed Salamanders Hemidactylum scutatum, and Marbled Salamanders Ambystoma opacum. However, the greatest migration is undertaken by the Spotted Salamander Ambystoma maculatum. This relatively large salamander spends the summer and fall in brumation, escaping the dry and the heat in underground retreats, waiting for ecological signals of the breeding season. When the cue of warm rain comes, the salamanders emerge in the thousands to return to the same pools they were born in, where, like their parents, they will engage in the same ritualistic breeding activity.

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Ephemeral wetland, near Brakefield Road in Sewanee

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Spotted salamander emerging from leaf litter

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Spotted salamander emerging from leaf litter

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Spotted salamander walking across forest floor

The males are the first to enter the pond. Here, even without females to impress, they swirl around in the leaf litter at the bottom of the pond, dropping spermatophores (see video taken at the pond on Brakefield Road here). The female salamanders arrive a week or so later. Upon entering the pond the females are swarmed by eager suitors, each waving his pheromones in her face, and gripping her with their legs so as to entice her to pick up their spermatophore, thus passing on their genetic material. After fertilization, the females attach their eggs to a submerged branch, where they swell with water to form a firm gel-like mass. Females come and go fairly regularly, completing their purpose and leaving the pond to return to their forest home. Males tend to stay longer, attempting to breed multiple times, giving themselves a better chance at reproductive success. As the eggs hatch, the pond is filled with thousands of small, gill-flaunting larvae, who in a few weeks will leave the pond on a rainy night to find a place to spend the summer.

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Spotted salamander egg mass

Emigration of young salamanders from the pond represents a huge transfer of biomass from an aquatic ecosystem to a terrestrial one. This transfer is one of the most significant roles of amphibians in food webs and ecosystems. These salamanders make up a huge portion of the forest’s vertebrate biomass, and engage in one of the largest movements in the eastern forests of America, and certainly one of the largest here in Sewanee.

All photographs copyright 2016 Saunders Drukker.

 

Salamanders of early winter (guest post by Saunders Drukker)

I’m delighted to share this guest blog post written by Saunders Drukker. Saunders is an Ecology and Biodiversity major at Sewanee (Class of 2017). He’s been studying salamanders and other herps for years. I hope you’ll enjoy his observations and photographs.

As the days here in Sewanee start winding down toward winter, many nature lovers’ subjects begin to disappear. Birds make their way south, mammals start looking for places to hide until spring, and trees go dormant, leaving many of us struggling to find things worth searching for. Thankfully, as everything else goes away, one group begins their most active period of the year: salamanders. Each year in winter salamanders become active by the thousands, moving about the forest floor searching for places to breed.

One of the main groups active at this time year is the Ambystomatids or Mole Salamanders. These stout little amphibians spend much of their year hiding underground, but when the weather cools down and the rains start up they begin to move toward their ephemeral breeding ponds. One of the most striking and most active at this time is the Marbled Salamander, Ambystoma opacum.

Marbled Salamander

Marbled Salamander

These salamanders come out from their underground hideaways and move to the locations of ponds before these depressions fill with water. Here, the salamanders breed and lay eggs in the muddy bed of the pond, where they guard them until the rains come. Once the pond fills with water, the adults return to the forest. The eggs hatch, filling the pool with thousands of larval salamanders. By laying their eggs in the pond before all the other species arrive, the Marbled Salamanders give their young quite the advantage. By hatching earlier than all others, larval Marbled salamanders become large enough to prey upon the smaller larval Spotted Salamanders Ambystoma maculatum once they arrive in spring.

Three Ambystomatid Salamanders of Sewanee, Spotted, Marbled, and Mole Salamanders

Three Ambystomatid Salamanders of Sewanee, Spotted, Marbled, and Mole Salamanders

It is not just the mole salamanders moving this time of year, though. The cool wet weather is ideal for almost all species found here on the plateau, especially the lungless species that require cool, wet conditions to be active. These salamanders, as their name implies, do not respire by use of lungs, instead they take oxygen from the environment around them, using their permeable skin to transfer oxygen and carbon dioxide. Some of the most easily found genera in Sewanee are Plethodon, Pseudotriton, Eurycea, Aneides, Hemidactylum, and Desmognathus. 

Zig Zag Salamander (Plethodon dorsalis)

Zig Zag Salamander (Plethodon dorsalis)

Two Lined Salamander (Eurycea cirrigera)

Two Lined Salamander (Eurycea cirrigera)

Northern Slimy Salamander (Plethodon glutinous)

Northern Slimy Salamander (Plethodon glutinous)

Red Salamander (Pseudotriton ruber)

Red Salamander (Pseudotriton ruber)

Green Salamander (Aneides aeneus)

Green Salamander (Aneides aeneus)

Green Salamander (Aneides aeneus)

Green Salamander (Aneides aeneus)

Four-Toed Salamander (Hemidactylum scutatum)

Four-Toed Salamander (Hemidactylum scutatum)

Cumberland Dusky Salamander (Desmognathus abditus)

Cumberland Dusky Salamander (Desmognathus abditus)

Cave Salamander (Eurycea lucifuga)

Cave Salamander (Eurycea lucifuga)

 

On any rainy cold night large numbers of these salamanders can be found moving across the forest floor, or even across roads, so keep an eye out when you’re driving on backroads. Sewanee boasts a huge diversity of salamanders, and winter is by far the best time to go out looking for them.

All text and photographs on this post, copyright Saunders Drukker, 2015.

Herp fest continues

Herpetological wonders continue to unfold. The Cumberland Plateau and the Southern Appalachians are among the most diverse places in North America (and the world) for amphibians and, to a lesser extent, reptiles. The last few weeks have not disappointed in encounters with this group.

We found this Seal Salamander during my Advanced Ecology/Biodiversity lab last week. The animal was in a creek in Shakerag Hollow. It was about five inches long. Seal salamanders spend most of their time in water, but will wander on land to feed, especially on wet nights.

Unlike its close relatives, the Seal Salamander has tough cornified toe tips, possibly to help it climb vegetation during its terrestrial forays. You can see the blackened tips through the ziplock bag.

This Slimy salamander was under a rock in the same creek. This species is usually found away from water, under logs or rocks, so this individual may have just been passing through. Slimy salamanders lay their eggs in moist places on land and their young never dip their feet in water. Young Seal Salamanders, on the other hand, are aquatic and have feathery gills.

I found this Marbled Salamander during Intro Biology class. It was hiding under a log in a dried up vernal pool. In a normal year, the salamander would wait for several more months before the pool filled up. This week’s phenomenal rains mean that the pools are now overbrimming. We’ll see whether or not the water stays. If so, this will be the earliest filling of these ephemeral wetlands that I know of in recent years.

Scott Summers, a freshman at Sewanee, found this spectacular Red Salamander last week under a log near Morgan’s Steep. Great find!

A Pickerel Frog in Shakerag Hollow. Note the squarish spots on the back. The similar Leopard Frog has rounder spots that are more randomly scattered over the back.

A Green Frog snuggled underwater with an acorn. Also in Shakerag Hollow. Note the nice clear water — thankfully, not all streams have been impacted by silt runoff into the hollow.

And from an entirely different habitat, located just a stone’s throw away from the vernal pool: a fence lizard enjoying the baking sun on a sandstone outcrop near Piney Point. These outcrops are incredibly dry and blazing hot. Fence lizards love the heat.

In closing, a frission of danger. This Timber Rattlesnake was on the trail in the northern Smoky Mountains where I was botanizing with the TN Native Plant Society last weekend. The botanists stopped briefly to admire the snake’s freshly molted shine, then returned their attention to petioles, leaf margins, and floral structure. The snake had thirteen rattles, so it has molted thirteen times. They molt two or three times a year, so this one is relatively young. They live up to twenty years.

Red eft

We found this beauty in Shakerag Hollow today during our stream surveys: a red eft, the terrestrial form of a salamander that has no fewer than four life stages. The eggs (stage 1) hatch in lakes, then the larva (stage 2) fattens up in the lake before metamorphosing into an eft (stage 3) that leaves the water and wanders on land for several years before returning to a lake and transforming into an adult red-spotted newt (stage 4).

The eft stage is very unusual; no other salamanders in our region have such a stage. The advantages are clear: the eft can feed on the forest’s abundant small invertebrates and grow to adult size without having to compete with any adults. This is a common strategy among other animals, especially insects whose young specialize on different food sources than the parents (butterflies and caterpillars; maggots and flies; lake-dwelling larvae and flying dragonflies). But why should only the newt adopt such a strategy among salamanders? No-one knows, but I suspect that part of the reason lies in the species’ powerful defensive chemicals. All red-spotted newt life stages have neurotoxins in their skin and are therefore well protected from predators. It was therefore presumably not that hard for evolution to draw the eft out of water onto land. Indeed, unlike all other local salamanders, efts wander the woods in broad daylight. They are seemingly the most fearless of all the woodland creatures, with the possible exception of hornets and yellowjackets. Like these wasps, efts advertise their noxiousness with dramatic colors. This one was about only two or three inches long, but was sighted from several meters away.

“Eft” is from the Old English for “newt” or “small lizard.”

Pelting rain, then mist, more rain, and…salamanders

Intermittent downpours are not ideal weather for outdoor classes, unless your topic for the day is: salamanders!

So a hardy (and uncomplaining — YSR!) group of cyclists headed out in the rain, destination Shakerag Hollow. This is the first of many days of salamandering for my Advanced Ecology and Biodiversity class. We’ll be documenting the local fauna and comparing communities among streams with varying degrees of sedimentation.

The focal stream for the day yielded many Spotted Dusky Salamanders, Desmognathus conanti. These stocky animals are fast movers: you need quick hands to catch them. They are about five inches long and hide under rocks, emerging at night and in downpours to feed on insects and other small prey.

Spotted Duskies stake out a tiny stretch of stream for their home range, so we made sure to put them back exactly where we found them.

In addition to salamanders, we found several crayfish, including this one, expertly captured and held by my colleague David Johnson, that has two babies attached to the underside of its tail. The females usually carry eggs in this position, but youngsters generally swim off on their own.

The woods were also full of fungi, including this stinkhorn……and a spectacular growth of what I think is “chicken-of-the-woods,” a species that is edible (to some; for others it causes considerable distress). This fungus was visible from about fifty meters away. It glowed through the mist of the forest. No, it burned. But salamander-like, we survived the fire.

Four-toed salamander with her eggs

This week’s theme seems to be salamanders, perhaps appropriate given that it is early springtime in one of the world’s hotspots for amphibian diversity. (An aside: when will TN sports teams figure this out? Titans, Predators, Kats, Tigers = yawn; Cave Salamanders, Spadefoot Toads, Barking Treefrogs, Mudpuppies = oh yeah, very memorable). I stopped by the Brakefield Rd ephemeral wetland this afternoon with the “Field Investigations in Biology” class. We found larvae of marbled salamanders, an adult mole salamander, and this four-toed salamander (Hemidactylium scutatum) guarding her eggs.

Her eggs are visible on the underside of the log which we temporarily lifted up to take a look. She'll stay with them for about two months, defending them from predators and keeping fungi at bay. The young will hatch, then move to the adjacent pond for a month, before finally taking the woods for the rest of their lives.

Four-toed salamanders are relatively small, with mottled brown backs and a constriction at the base of their tails.

All four-toed salamanders have bold black spots on their white bellies -- very distinctive. (We flipped her back upright after this five second demonstration of her spotty belly.)

This species builds its nests at the edge of ephemeral pools, in sphagnum moss, and along stream banks. Because of its specialized habitat requirements, it is listed as “vulnerable” and “in need of management” in Tennessee.

I did not have my camera on me, so special thanks to Julia Galliher who took those photos with her phone. (iPhones are this week’s subplot on the blog, it seems)

Microsafari bycatch

Our search for the mini-creatures of the world also turned up some interesting macro-organisms. Spend a few hours in the woods with a bunch of biologists and you’ll see a good array of remarkable critters. Here is a selection.

Zigzag salamander (Plethodon dorsalis/ventralis -- can't tell which without a DNA-o-tron), found under a limestone slab. This species is strongly associated with karst limestone, especially along streams and near springs. The females lay their eggs in caves and brood the eggs until they hatch. These are long, skinny salamanders, like pencils.

Slimy salamander (Plethodon glutinosus), also found under a rock. Black with silver spots: beautiful. When handled, they produce gluey defensive slime that gums up your fingers.

Admiring Plethodon glutinosus

...and slimy makes her escape

Box turtle (Terrapene carolina) shell. The colored plates are made from keratin, the same material as our hair and fingernails.

The same turtle shell seen from below. The animal’s spine is visible and, above that, the carapace which is made from fused ribs combined with dermal bone. So, evolution has flipped the ribs of turtles onto their backs and fused them into a solid plate.

The tail of a spotted salamander...evidently a raccoon or some other predator ate well. We found spotted salamander eggs in a nearby pool, so life goes on, the torch has been passed, etc, etc ...fill in your own favorite death-surmounting cliche here...

Hepatica nobilis. Most Hepatica here are white or pale purple. This one was unashamedly ultra-purple. Yeah, the torch got passed to this one alright.

A nematomorph, also called a “horsehair worm.” These are parasites inside the bodies of insects. When the worm is ready to exit, it causes its host to jump suicidally into water, then the worm rips open the insect and emerges. These lovely critters feature in the first chapter of my book, The Forest Unseen -- nematomorphs surely embody one pole of nature’s range of cooperation and conflict.