Updating Species Distribution Maps for the Northern Redback Salamander (Plethodon cinereus)

Northern redback salamander (Plethodon cinereus)
Photo by Brad Sylvester, copyright 2012.

The New Hampshire Fish and Game Department has lists of every species in the state (excluding invertebrates due to the huge numbers) and for many, they have species maps showing confirmed sightings of the specific species by town. On their website, they ask for the public to help them keep their species maps updated by reporting sightings in locations in which the species has not been previously or recently reported. For example, the species map for the Northern redback salamander (Plethodon cinereus) has vouchered or confirmed reports of the species in many towns throughout the state, but not in Strafford, where I live.

However, As I was walking through the woods in my backyard, yesterday, I happened to lift a piece of wood from the ground and spy a Northern redback salamander on the ground underneath it. I am rarely out in the woods without a camera, so I took several photos which are required for NH F&G to voucher the species report for the town.

The Northern redback salamander is usually found
beneath fallen logs or stones in the forest. It prefers
a very moist environment.
Photo by Brad Sylvester. Copyright 2012

To get Strafford added to the species map for the Northern redback salamander, I'll send the photos to the non-game wildlife division of the NH Fish & Game Dept. along with the date and specific location of the sighting.

The towns colored white on the species map have no reported sightings of the species, but that doesn't mean it isn't there. In fact, if a number of towns all around the unlisted towns have confirmed sightings, then it is quite likely that the species does exists in those in between spaces, but simply hasn't been officially reported. That's where individuals like you and I can help. If we see a wild animal species in our town, we can check the map for that particular species to see if it has previously been reported there. If not, we can help NH F&G update their species distribution maps by providing them with a report of our sightings, as I am doing with the Northern redback salamnder that I found in my yard. If you can, include good photos that allow a positive identification of the species.

Here's the link with the reporting form and complete instructions.

Where to find Northern Redback Salamanders

The Northern redback salamander is a species that you will rarely see unless you are actively looking for it. It spends almost all of its time under fallen logs among the leaf litter on the forest floor. To find them, then, you'll need to carefully lift fallen branches that look like there might be room enough under them for a small salamander to wriggle around. Whether you find one or not, always replace the branch as you found it (being careful not to squish anything that might be living there, of course). Caudata. Culture notes that many of these salamanders live entirely underground and rarely come up to the surface at all. If you find them on the surface, they say, you can be assured that there are many more underground in the area.

Population Density

Bob Pickett's Appalachian Nature website cites studies showing that as many as 1000 Northern redback salamanders can live in a single acre of prime habitat. That means I might have thousands of these salamanders living in my yard which includes about 4 acres suitable for Northern redback salamaders. That makes them almost certainly the most numerous vertebrate in the Northeast forest.

They will often remain stationary if discovered, relying on their color to help them blend into the forest floor. They are deceptively fast, and will try to burrow underneath leaves or anything else they can find to get away. The Northern redback salamader makes up for its very short little legs by undulating its body from side to side almost like a snake. This movement effectively picks up its feet and moves them much farther ahead than they'd move on their own. If unable to escape, they use the lizard trick of dropping a part of their tail which wiggles to distract predators while they make their escape. Over time, the tail will regenerate.

Northern redback salamanders may be found either with the reddish stripe on their back as shown in my photos and video or in a more uniform slate color without the red stripe. They grow to about 5 inches long.

I mention that they are often found under fallen logs, and, in my experience they prefer wood to hide under, perhaps because it holds moisture better. This species, will, however, use almost any available cover, rocks, old tarps, or just about anything that will help keep them hidden and moist. It's not unusual to find them nestled into old woodpiles.

Quick facts about the Northern redback salamander (Plethodon cinereus):

The genus Plethodon denotes woodland salamanders. They are amphibians even though they do not willing enter water, even to lay eggs.

Diet and Feeding: The Northern redback salamander eats insects and almost any other small creature it can catch and swallow. According to a website compiled by Kathy Ching and hosted by Western Connecticut State University, they feed by thrusting their tongues forward, frog-like, to catch small prey. The University of Michigan website notes that during a dry spell or drought the Northern redback salamander is limited to foraging under rocks and logs where it is still moist. Because food is more scarce there, they may eat very little during these periods, living off stored fat acquired by gorging during periods more conducive to their feeding methods. After a rain, when the entire forest is still wet, they may wander the forest floor or even climb up on plants to find food.

Where does the Northern redback salamander go in winter? Salamanders are cold-blooded, and the ground here freezes fairly deep in the winter. That means that the Northern redback salamander must hibernate in the winter.

Range: This species can be found in a roughly triangular range with Wisconsin, Nova Scotia, and  South Carolina at the corners.

IUCN Red List Status: Species of Least Concern due to large population, widespread range, and adaptability.

Lifespan: The University of Michigan's Animal Diversity website lists a figure of 25 years in captivity for the lifespan of Plethodon cinereus, however, they note that there is little real data and that comparisons to other similar species must be used to calculate wild lifespans which they put at something over 10 years.

What eats Northern Redback Salamanders? Many birds, raccoons, skunks, opossums, and snakes prey on redback salamanders.

Lifecycle: The female lays up to 14 eggs in a cluster in the springtime, usually attached to the roof of the chamber in which she lives. She'll stay with the eggs until they hatch. Unlike most amphibians, the Northern redback salamander does not lay its eggs in the water, but has instead evolved to lay eggs which are encased in a water-filed sac. The babies develop inside the sac, thus bypassing the larval stage and emerging fully formed.

Behavior notes: Northern redback salamanders are highly territorial and will actively defend their territories against others of their species.

Physiology notes: The Northern redback salamander is a lungless salamander. It breathes through its skin and relies on moisture to make that process efficient.

Alternate names: Northern red-backed salamander

Taxonomy of the Northern Redback Salamander:

Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Caudata (Salamaders)
Family: Plethodontidae (lungless salamanders)
Genus: Plethodon
Species: Plethodon cinereus


 

Eastern Red-spotted Newt, From Red Eft to Salamander

Can you spot the red eft in this picture?
Click for a larger version.
Photo by Brad Sylvester, copyright 2012

One of my favorite three-letter Scrabble words is "eft." An eft, more specifically a red eft, is the juvenile form of the Eastern red-spotted newt (notophthalmus viridescens).

Newts and Salamanders

The red eft is commonly called a newt, but where I grew up, the adult form is called a salamander. It looks and acts very different once it reaches the adult stage, so many don't realize that they are, in fact, the same creature.

A closer view shows how the red eft's coloring
blends in with the browns, yellows and oranges
of the forest floor in addition to advertising
its toxic nature.
Photo by Brad Sylvester, copyright 2012.

The juvenile Eastern red-spotted newt lives on the forest floor away from bodies of water, though it does prefer a moist environment. The adult is aquatic, and while it may occasionally climb out of the water onto the shore of a piece of driftwood, it lives, eats, and lays its eggs in the water.

They are also quite different in coloration and somewhat different in body shape. The juvenile red eft form is bright orange. It has small red spots outlined in black on its back and its belly is a lighter yellow-orange. The adult retains the red spots, but is a dark olive green that blends in well with mud. The underbelly of the adult tends toward yellow. Both have scattered, small black spots, like flakes of pepper on their sides and bellies.

The adults have tails better equipped for swimming. Unlike the juveniles', the adults' tail grows a thin ridge on the top and bottom to give it more surface area with which to push against the water as it swims.

Adult Eastern red-spotted newts prefer slow-moving bodies of water. They are most often found in still ponds or the shallow back-waters of larger lakes. They drift lazily at the surface or dive down to the bottom to forage in the muck. They are relatively easy to catch with a minnow net or even bare hands.

Despite the toxins in their skin, the Eastern
red-spotted newt can be safely handled.
Photo by Brad Sylvester, copyright 2012.

The orange juveniles are usually spotted walking along the forest floor, especially after a rain when the leaf litter is damp. Red efts may live on land for as many as three years before returning to the water as adults, according to the New Hampshire Fish and Game Department. They also note that both the juveniles and the adults are poisonous, secreting toxins in their skin to dissuade predation. Despite this, they are completely harmless to humans and can be carefully handled (though not eaten) without fear.

Quick facts about the Eastern red-spotted newt:

Classification: The Eastern red-spotted Newt is an amphibian like all salamanders, and not a reptile like lizards.

Diet: The Eastern red-spotted newt is generally carnivorous, eating insects, small smalls, worms, and the eggs of frogs and fish. NHPTV says that the red eft especially dines on springtails.

Where does the Eastern red-spotted newt go in the winter? The adults can survive and remain active all winter long under the ice. The land-based juveniles hibernate under rocks or logs.

Life cycle: Adults lay eggs which are individually attached to underwater vegetation although a female may lay as many as 400 in a single season. The eggs hatch into a larval form, like a frog's tadpole. The larva develops into the red eft and leaves the water for a period of 1-3 years before maturing into an aquatic adult. (Note that the IUCN data page says that red efts may persist in the juvenile stage for as long as seven years, but most sources list 1-4 years as typical. It seems counter-intuitive to me, that they would spend seven years as juveniles with an overall natural lifespan of 5-15 years. Perhaps, in rare cases where persistent drought or lack of food stunts their development or prevents them from finding a resident body of water, but under ordinary conditions, I'm not convinced of the seven year figure.)

Lifespan: Eastern red-backed newts can live up to 15 years according to the Connecticut Wildlife website.

IUCN Red List Status: The IUCN lists the Eastern red-spotted newt as a species of least concern due to large numbers and widespread habitat.

Taxonomy of the Eastern red-spotted Newt:

Kingdom: Animalia
Class: Chordata
Phylum: Amphibia
Order: Caudata
Family: Salamandridae
Genus: Notophthalmus
Species: Notophthalmus viridescens