Herp Hunting: Part 3 – Toxic Efts and Defensive Mothers

Previously, I wrote on the diversity of the order Caudata, the salamanders, of North America, singling out the hellbender and Jefferson salamander, which each have unique adaptations for surviving. Now I’d like to introduce two more interesting New York species: the eastern, or red-spotted, newt, and the red-backed salamander.

Let’s start with the eastern newt!

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Eastern newt (red eft stage) outside my house

Eastern newts (Notophthalmus viridescens) are classified into the family Salamandridae, the newts, consisting of about fifty-three species, most of which are found in Europe, Asia, and North Africa. Eight distinct genera have been described from the fossil beds as having been represented in the Cenozoic Era. Members of the Salamandridae family lack distinct costal grooves, produce skin toxins, have grainy/warty skin, and bright coloration.

James W. Petranka comments in his book, Salamanders of the United States and Canada, that the eastern newt has “one of the most complex and variable life cycles of any North American salamander.” And I agree. In general, most members of this species undergoes 4 stages in life: egg, aquatic larva, terrestrial red eft juvenile, and aquatic adult. But depending on habitat conditions, whole populations may skip one stage of the metamorphosis, or produce extra physiological adaptations where other populations don’t, such as gills in adults.

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Pond-form larva. Photo by Brian Gratwicke.

To get started, let’s look at what is ‘typical’ in the eastern newt. It would appear much like other salamanders form the egg to the red eft stage, as the salamander is born from an egg into a pond-form larva with large external gills and a high dorsal and tail fin that it uses to move around in the slow moving ponds and lakes that it inhabits. Eastern newt larva are generalist carnivores that will feed on almost anything that can be caught, including others of the same species, and can survive in fairly high densities together. After 2-5 months in the aquatic larval stage, the animals metamorphize into juvenile red efts, with a small percentage of individuals overwintering as larva. Some populations do not pass through the red eft stage, in which lack of suitable habitat appears to be the trigger for  such a condition.

So far, we follow ‘typical’ salamander life history, but here we diverge, because though the red eft looks like a typical salamander, it isn’t. Red efts often travel exposed during the day time because they produce a toxic skin secretion that makes them unpalatable to predators. We recently had one wander right up to our front porch mid-day, where it camped out for about 24 hours. Though the bright coloration is a warning to a would-be predator, just like cobras in Africa that are eaten by badgers, red efts are still predated upon by bullfrogs and some species of turtles.

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Our red eft

A red eft may wander around for three years or more before it reaches sexual maturity. Most adult populations take on an aquatic form in which the animals are olive green to yellowish brown with a pale yellow belly, and flecked with speckles as well as red spots bordered by black along the back, hence the name ‘red-spotted newt.’ The tail of the adult is half of the body length and vertically flattened. Due to lack of suitable slow-moving water habitats, in some populations, the adults remain terrestrial. These adults resemble the aquatic adults except that the skin is more granular and the tail is less keeled. To mix it up even more, some eastern newts remain aquatic and gilled for their entire existence, a condition also influenced by their habitat. These aquatic adults look like a mixture of the lunged adults and aquatic larva.

Here in New York State, eastern newts are not a species of special concern, but the New Hampshire Department of Fish and Game lists them as such. Here in New York, they seem to be quite populous, and Mr. Petranka claims human land disturbances, man-made ponds, and beaver reintroduction a to have benefited this creature. In New Hampshire, development of agricultural lands to commercial, and deforestation may be negatively affecting the newts.

Check out this other blog, where the authors are also writing about red efts: The Southern Highlander

Tips for finding eastern newts:

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Red eft by our porch

1. The general steps I outlined in my post Herp Hunting: Part 1 – Diverse Salamanders holds for finding red efts. While researching for this post, I found it recommended over and over to search after the rain. Keep your eyes peeled for bright orange while you look!

2. If you find an eastern newt adult or a red eft, depending on your state’s laws, you may handle it, but be sure that your hands are kept moist and are clean of sunscreen and bug repellent. It is highly recommended that you wash your hands after handling an eastern newt, as their skin secretions can be toxic to humans as well.

3. Look for aquatic adults and larva by dipping a net into a pond, a lake, or a wetland and examining the contents. Be sure to return all catch back to the pond.

4. Check your state’s regulations and laws before handling or taking wild newts, especially on public property. Large fines or even jail time would be a terrible way to end a harmless hunt for a pet.

Now, let’s look at the red-backed salamanders!

Red-backed salamander

Red-backed salamander in our woods

The red-backed salamander (Plethodon cinerus) is a common salamander over much of it’s range in the northeastern US and southeastern Canada.  It is a member of the family Plethodontidae, the lungless salamanders, of which there are approximately 250 species.  This family of salamanders lack lungs and have nasolabial grooves, which are little channels between the upper lip and nostrils that carry waterborne chemicals that influence chemically mediated behaviors, such as mating.

Two color morphs occur in the red-backed salamander. One morph has an orange-red to red dorsal stripe that runs from the top of the head down to the tail. The sides of the red-backed morph are dark, and the underside, or venter, of the body is speckled black and white.  The second morph looks like the red-backed morph, but lacks the red stripe above. This second color type is referred to as a ‘lead morph.’ Individuals that are intermediately striped and unstriped are also occasionally encountered. Unlike the hellbender, which I wrote about in my previous Herp Hunting post, sexual dimorphism is small, with males and females measuring between 2.5-4.9 in (6.5-12.5 cm) from snout to tip of tail.

Red-backed salamanders inhabit deciduous (hardwood), northern deciduous, and mixed deciduous-conifer (pine) forests. They can be found in leaf litter, and under rocks and fallen logs. They are generally absent or in very low densities in highly acidic soils, such as in pine forests.

Red-backed salamander, lead morph

Red-backed salamander, lead morph. Photo by Brian Gratwicke via Wikimedia Commons.

As stated above, the red-backed salamander is part of the Plethodontidae family, which are the lungless salamanders. These lungless animals breath entirely through their skin and the tissues lining their mouths. It is obligatory, therefore, that their environment be moist in order for them to breath.

Some scientists believe salamanders, like frogs, to be indicator species. The presence or lack of an indicator species can help scientists understand the health of the surrounding environment. Because a salamander’s skin is porous, as they take in both oxygen and moisture through it, chemicals in the environment that the salamander comes in contact with would also pass through it.  Sometimes, a salamander can cope with what it comes in contact with, sometimes not. Pollutants in the environment will either cause death in amphibians, mutations, or cause them to move on if possible. An example of a situation might be if salamanders were once populous in a wood or region, but over the following 5-10 years, trends indicated that it was disappearing, this would be an inidication that something was being altered in their habitat to make it unsuitable.  A pollutant that might be irritating to a salamander’s skin would be salt from de-icing the roads in winter which can cause an unbalanced pH in the water moving through the environment from the sides of the roads. It’s amazing how everything is so connected, isn’t it?!

Besides not possessing lungs, red-backed salamanders are different from other the salamander species that we have looked at so far in that they deposit their eggs on land and their young are born looking like mini adults.  Females suspend their egg masses from the roof of a crevice or cavity, then remain coiled around the cluster. Like all good mothers, brooding females will aggressively defend their eggs.  This is actually done against other females, who come to cannibalize the eggs! Why do they do this? I couldn’t find a direct answer, but as individuals will cannibalize juvenile salamanders, my educated guess would be that it is mostly about getting an “easy,” nutritious meal, though I know I’d fight to the death to save my children, and I bet a brooding female red-backed salamander is not too much different. Another theory would be that the attacking female would not only get a nutritious meal, but also a coveted habitat for laying her own eggs.  I did not see any indication in my research that said whether or not attacking females are usually gravid (aka pregnant). (If you know, please leave a comment! I’d love to find out!)

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Juvenile and adult red-backed salamanders. Photo by batwrangler.

Incubation of the eggs lasts 6 weeks, with hatching from August to September.  Mature embryos are reported to have gills, which they lose just before or after hatching. Red-backed salamanders do not pass through an aquatic larval stage, but are born looking like miniature adults.  Perhaps because of this, the female and young remain together in the nest site for 1-3 weeks before dispersal.

Red-backed salamanders are common throughout their range, and are not a species of concern.  Never-the-less, local populations do face pressures from logging, habitat fragmentation and invasive species.

Tips for red-backed salamander hunting:

1. Steps outlined for looking for live salamanders in Herp Hunting: Part 1 – Diverse Salamanders, are pertinent for red-backed salamanders.

2. If you handle a live animal, be sure your hands are moist and clean of any bug repellent or sunblock, especially because these salamanders are so sensitive to what their skin comes in contact with.

3. Check your local regulations about handling and taking wild animals. I know that in New York, you are not allowed to remove plants or animals from public areas.

Lastly, I hope that you have enjoyed my series about salamanders, and that it inspires you get outside and shift through the leaf litter a little.  Don’t worry about getting dirty – you will!

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Photos where no credit is given are mine.  Click on photos with credit given to be redirected to Wikimedia Commons or photographer’s Flickr page for more information, including Creative Commons license.  Photos connected to photographer’s Flickr page where found on photopin.com.

 

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