Secretive Blackwater Salamanders

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By now you’ve probably noticed that this is not the typical format for Fieldnotes. I’ve been dabbling with the idea of a written format for a little while now, not to replace the video format, but as a way to diversify content and make it easier for me to produce monthly installments. Not all my field projects can be shared here. Some private grants or government contracts come with stipulations that keep us from producing media or publicly discussing aspects of the projects. Other research either involves very sensitive field sites or field methods that we prefer to not share publicly. Illegal collection for the global pet trade and impacts from recreational field herping are very real problems for many at risk species, and we want to always keep their protection our top priority. So, these written entries will not focus so much on Orianne Society research projects, but rather on stories from the field, interesting natural history observations, my herp photography, small collaborative side projects, or species that might be difficult to showcase in the current video format. I hope everyone finds this informative and enjoyable, and I should be back with some new videos in the next couple months. Okay, let’s get started…

Mud Salamander (Pseudotriton montanus)
Mud Salamander (Pseudotriton montanus) - Ben Stegenga

As many of you know, the southeastern Coastal Plain boasts some impressive reptile and amphibian diversity. I am very fortunate that my various field projects and associated travel at the Orianne Society allows me to see many of these species while “on the clock,” or at the very least, provide me with good opportunities to pursue them on my own time. Outside of work I’m an avid field herper and amateur wildlife photographer, so much of my free time is spent trying to photograph species locally or traveling in search of species I’ve not yet seen before. If I can report rare species observations, publish county records, or contribute to our knowledge of natural history in the process, that’s the icing on the cake for me. And fortunately, that’s exactly how this story plays out.

My first true salamander focused foray into the blackwater creek swamps of southeastern Georgia took place years ago with my friend and former colleague Jonathon Bolton. We decided to spend a Saturday exploring a small blackwater creek system. We hiked upstream along the main channel to where it became somewhat braided, and the shallow floodplain swamp spread out beneath a dense canopy of tupelo and other hardwoods. There was some muck, but the ground remained fairly firm with thick patches of leaf litter substrate. The occasional opening in the canopy revealed patches of aquatic vegetation exploiting the precious sunlight that reached the acidic, tannin-stained water. 

Many-lined Salamander on leafy substrate
Many-lined Salamander (Stereochilus marginatus) - Ben Stegenga

We had our crosshairs set on two highly aquatic salamanders that are seldom seen by anyone unless they’re making a concerted effort: the Northern Dwarf Siren (Pseudobranchus striatus) and the Many-lined Salamander (Stereochilus marginatus). These are very unique animals when compared to the rest of the salamander diversity of the region. The Many-lined Salamander is the only member of the genus Stereochilus, and while Dwarf Sirens are in the same Family as our other siren species (Sirenidae), they are strikingly different in appearance. They more closely resemble a striped #2 pencil than the dark, robust bodies of other sirens, some of which can reach close to a meter in length. 

As we hiked towards our destination, we opportunistically rolled logs along the way in hopes of finding Southern Dusky Salamanders (Desmognathus ariculatus) and hypothesized why there were no Mud Salamander (Pseudotriton montanus) records from this site. Both of these slightly more terrestrial species can be equally tricky to find, and so we would make a much more focused effort to find them on a different outing. Interestingly, it’s not uncommon for these four very different salamanders to be found in close proximity to one another in these acidic creek swamp systems, utilizing slightly different microhabitats. They don’t always occur together, but they overlap enough that it’s hard for me to think about any of them without considering their relationship with the others.

Northern Dwarf Siren (Pseudobranchus striatus)
Northern Dwarf Siren (Pseudobranchus striatus) - Ben Stegenga

As many first experiences in a new environment play out, you learn the habitat and the species by trial and error. Of course you read up on the ecology of the species beforehand, but there’s always going to be variation and nuance in habitat structure and how those animals operate within that specific location. It proved to be a taxing introduction. We sifted leaf litter and dip-netted every conceivable substrate and aquatic vegetation we could find. Jonathon was mostly dip-netting with one hand, as he had been bitten by a dog earlier that morning but didn’t want to miss out (dedication at its finest!), and I was now scooping leaf litter with the decapitated hoop of a dipnet. The repeated strain of scooping muck, leaf pack, and woody detritus proved too much for the aluminum handle, which snapped at the base of the hoop. 

We had put hours into this endeavor without much to show for it, apart from aching backs and a couple Lesser Sirens (Siren intermedia). We agreed to give it another solid half hour before calling it quits, and that ended up making all the difference. In that final push, we netted both species! The Many-lined Salamander was exactly what we had hoped to see, a large adult in perfect condition, scooped up with a pile of submerged leaves that appeared identical to the previous hundred leaf packs. The Dwarf Sirens on the other hand, were not what we had expected at all. By some stroke of luck, I had netted two Dwarf Siren eggs with fully developed larvae inside! Once I realized what I was looking at, I quickly put them into a tray of water, so I could photograph them. But within minutes they began to break through the egg membranes, and they eventually fully hatched before our eyes! 

Larval Northern Dwarf Siren (Pseudobranchus striatus) hatching out of eggs. Photo by Ben Stegenga
Larval Northern Dwarf Siren (Pseudobranchus striatus) hatching out of eggs. - Ben Stegenga

Even though I still really wanted to see an adult, this was pretty special, and I quickly relayed my observation on to my mentor and field biologist extraordinaire, Dirk Stevenson. This wasn’t a completely unique observation, but it got the wheels turning in Dirk’s head, and within days he had looped in a few other amphibian specialists. What started as a chance observation had snowballed into a collaborative effort to compile field observations and museum records of eggs, larvae, and juveniles. 

The reproductive life history of Northern Dwarf Sirens was largely unknown, but now we felt we could attempt to determine when reproduction was taking place. After many more days in the field, measuring live and preserved larvae, and dissecting gravid female museum specimens, we published our discoveries in Herpetological Review. It wasn’t ground-breaking work, however, it was a small piece of the puzzle that no one had put together yet. And when you’re dealing with organisms that are notoriously difficult to study in the wild, any accomplishment feels quite satisfying.

Southern Dusky Salamander (Desmognathus auriculatus)
Southern Dusky Salamander (Desmognathus auriculatus) - Ben Stegenga

This is how my relationship with these secretive salamander assemblages began, and it persists to this day. Each year I return to a handful of sites with fellow salamander afficionados to pay these species a visit and see what secrets they might reveal. It’s a welcome and rewarding challenge, and we’re occasionally rewarded with observations that helps us better understand their behavior, distribution, and ecology. There’s something about this unique assemblage of cryptic salamanders that I find endlessly fascinating, and I hope my close circle of salamander fanatics continues to toss around questions to explore. For being animals that most people don’t even realize exist, they are all charismatic in their own way, and deserving of our admiration and conservation efforts. 

We still have considerable gaps in our knowledge about all four species in the Coastal Plain, and time may be against us. The most obvious example is the plight of the Southern Dusky Salamander. Unbeknownst to many, it’s one of the most imperiled salamander species in the Southeast, as it has mysteriously vanished from much of its historic range and is now entirely absent from the panhandle and much of peninsular Florida. Recent genetic work has also shown that salamanders previously considered to be D. auriculatus from Virginia to just south of the Savannah River are now recognized as a new distinct species, the Carolina Swamp Dusky Salamander (Desmognathus valtos). This leaves us with only a handful of scattered persisting populations of Southern Dusky Salamanders in southern Georgia and northern peninsular Florida. And while we don’t yet know exactly what’s causing the declines, we do know our native salamanders are facing numerous anthropomorphic threats like water pollution, destructive timber practices, habitat loss, fire suppression, mining, introduced disease, feral hogs, climate change, and the stripping of wetland protections, just to name a few. That’s quite a lot for these little amphibians to deal with on their own, so they could use as many people in their corner as possible. 

This special little assemblage of blackwater salamanders may not be as well-known as Eastern Indigo Snakes or as beloved as Gopher Tortoises, but my hope is that people will begin to see them as equally valuable parts of our rich southern landscapes and rally behind them in the same ways.