Tigers by the Tail

“That’s no spotted salamander” I thought as I looked down at the large, blotched amphibian clambering its way over the paved road.  For one thing, the salamander’s head was enormous with drooping jowls that turned its expression into a grimace.  It looked so top-heavy, that I was surprised the animal didn't tumble over itself with each step.  Its sleek body was a deep purplish-brown with rich caramel spots that extended from its snout down the length of its huge, rudder-shaped tail.  As I gingerly picked the salamander up off the road, the tip’s of its fingers gripped my hand with what felt like tiny claws (not true claws of course, just hardened keratin on the finger tips)—a tiger of a salamander indeed.  

I was back home in northeastern Ohio for the 2018 Ohio Biological Survey Conference held at the Cleveland Museum of Natural History.  It was nostalgic to walk the halls lined with the same taxidermied dioramas and fossil bones that I first fell in love with as a young boy.  Growing up, my grandparents would take my brothers and I to the "Dinosaur Museum" every chance we got.  It’s only a short 30 minute drive from where we lived, but to us, a trip to the natural history museum felt like a week long excursion.  We spent hours staring at the displays, imagining worlds long past.  We traveled to space, to the rainforest, to the Cretaceous extinction—admiring everything from trilobites to terror birds.  

After presenting our box turtle poster and listening to a day of talks, I was eager to get out into the rain and do some herping.  As I considered searching a nearby spot for unisexual ambystomids, I overheard some folks talking about eastern tiger salamanders (Ambystoma tigrinum). Of course I joined the conversation. Tiger salamanders are one of those species that first sparked my interest in Ohio's amphibians. I had dreamed of finding one for years, but I never knew where to look.  My fellow natural history enthusiasts were kind enough to share some possible locations.  The perks of building connections.

Later that night, my dad and I donned our rain gear and headlamps, and set out for northwestern Ohio. Back when I was just a kid, we saw our very first salamander migration together.  It feels like a lifetime ago now.  From humble beginnings, we eventually traveled all over northern Ohio in search of different herps and birds.  My dad is more of a hiker than a wildlife watcher, but he is always interested to see what new slimy or scaly creature I've pulled out of the muck.  It had been some time since the two of us went herping together; it was nice to get back out in the field with him.  

As we arrived at our destination, I was glad to see the temperature had jumped up to the mid-40s.  Still chilly, but plenty warm enough for amphibians to start moving.  As we hiked towards the vernal pools, the rain turned the boardwalk's already slick surface into a slip n' slide.  Shuffling carefully along, I heard the first frog of the night.  Like fingers scrapping across a comb, the caller was unmistakable: a western chorus frog (Pseudacris triseriata).  I had only seen one western chorus frog before and was hopeful the night would produce a second.  

Chorus frogs and tiger salamanders breed in the temporary vernal pools associated with most early breeding amphibians.  Tigers, however, prefer deeper, more permanent bodies of water compared to most mole salamanders, and will even breed in fish-free ponds.  We scanned the shallows of the flooded woodland, trying to pick out eyeshine or a swimming silhouette.  No frogs, no salamanders, no egg masses.  The pools appeared to be devoid of breeding amphibians.  I decided to switch tactics and try our luck road cruising.

Immediately, we started to see amphibians.  As I stopped to move wood frogs and spring peepers off the road, one little, tan frog stood out.  It was slightly smaller than the average peeper, with three distinct vertical stripes running down its back.  Our chorus frog, what luck!  Western chorus frogs are some of the earliest breeders in Ohio, and can be found across much of the state and the US as a whole.  They are usually less abundant than spring peepers, and are more often heard than seen.  We found only one the entire night.

Like the western chorus frog, eastern tiger salamanders are a widely distributed species. They occur across western Ohio (and on Kelley's island) and their range extends from the east coast to the edge of the great plains.  Close relatives of the eastern tiger salamander (like the barred and the California tiger salamander) can be found throughout the west. During the non-breeding season, adults secret away in underground burrows in forest and prairie habitats. They are the largest terrestrial salamander species in the state, and in some cases, exceed 10 inches in total length.  As larvae, tigers are notoriously cannibalistic, readily consuming their smaller siblings.  

After snapping some shots of the chorus frog, we cruised up our first tiger of the evening. My shout of delight was the signal to pull over.  "It's huge!" my dad commented, as we knelt down to photograph our find.  Crouching on my hands and knees in the pouring rain, he scoffed at my indifference to the cold and wet whenever amphibians are involved.  The rain didn't bother me for good reason.  This tiger salamander was easily the largest mole salamander I had ever seen, probably 6 or 7 inches in length. It froze in the light of my headlamp, blinking its round, golden eyes in bewilderment.  After realizing we weren't about to eat him, the salamander resumed its trek towards the vernal pools.

I was glad to get some decent pictures on the road, because the tiger refused to cooperate when I placed it on natural substrate.  Despite my best efforts, I couldn't convince the stubborn salamander to lift its enormous head.  Splaying its legs out awkwardly to the sides, it squirmed and buried its snout under pine needless and other woody debris.  I tried for ages to get a good angle in the pouring rain, risking my camera for a photo I never got.  Ah well.  That's the way it goes sometimes.  We found three adult tigers by the end of the night, none of which allowed for my glamor shot.  

Note the split lip on this female.

The second tiger salamander we discovered was even larger than the first.  Its tail alone must have exceeded 5 inches in length.  Examining each tiger closely, I noticed how beat up they looked.  Old scars and battle wounds covered their spotted bodies—a chunk out of the tail here or a split lip there.  Contending with shrews and voles is the price these amphibians pay for living inside mammal burrows.  Rodents and shrews can be quite the adversaries, even for a salamander so large.  Noxious skin secretions make mole salamanders unpalatable to most mammalian predators, but predation rates can still be high.

I moved each of the tiger salamanders across the road in the direction they had been heading.  Traffic was light, but we still saw one crushed salamander and several dead peepers and wood frogs.  These slow-moving amphibians are completely defenseless when it comes to roadways and vehicles.  Helping a few to safely make it across the road was the best we could do.  As the rains dwindled, we headed for home.  With luck, the nearby vernal pools would soon be full of calling frogs, courting salamanders, and egg masses.  I hoped to return soon to witness their breeding first hand.

Tale of Two Salamanders

I held tight to my camera as the truck lurched forward, front tires plunging into several inches of mucky water.  Carl and I had chuckled at the prominent yellow signs, declaring “road may flood,” on the way in.  With each pass around the forested wetland, the water had risen by several inches, sinking our tires further and further into the oily blackness.  With the road now well under a foot of water, I was beginning to question our bravado.  “What is that!?” Carl exclaimed as something furry and brown half scurried, half swam out from under our advancing vehicle.  It was a muskrat, swimming over the two lanes like this was just another stream.  As the aquatic rodent dove under the surface, its body undulated, revealing a long, flattened rat-like tail.  

Getting stuck on some back country road an hour south of Athens wasn't on my to-do list for the night. Thankfully, Carl's trusty four-wheel drive pickup rumbled heartily through the deepest stretches of water. I hadn't anticipated how quickly the surrounding wetlands would overflow, turning the entire landscape into one big vernal pool.  As the rains picked up, the light traffic dropped to about zero.  This was good for migrating amphibians and other water-logged wildlife, but I wondered how long it would be before anyone noticed us if we did get stranded out here.

Cambarus bartonii cavatus an undescribed species.  Note the dozens of babies under its tail.

Reaching higher ground, we spotted something small and shiny crawling lamely over the asphalt.  Expecting an injured amphibian, I was instead met with the largest crayfish I had ever seen.  This land-dwelling crustacean (Cambarus bartonii cavatus, evidently an undescribed species) was a good sign for the mole salamanders we were looking for.  Crayfish dig extensive burrows in the surrounding woodlands, lawns, and agricultural fields, providing fossorial amphibians with a refuge during the summer and winter months.  Rain floods these burrows and forces their occupants to find new hiding places.  Whether it be invertebrates, amphibians, reptiles, or even mammals, rain makes wildlife move.  As we drove along, the eyeshine of an opossum was illuminated by our headlights; the two eery points of green light faded back into the darkness as the gray, shaggy marsupial moved away.

Spring peepers and wood frogs hopped across the road every few feet.  Their high pitched whistles and guttural whines resonated from the nearby pools and streams.  Carl hadn't visited these routes for a few years (save for a brief trip we made in late autumn).  I was impressed that he retained a mental map of the area.  When I road cruise (the term herpers use for driving around and looking for amphibians and reptiles), I usually creep along at 15-20 miles per hour.  Any faster and I worry I’ll miss or hit something.  Carl, on the other hand, does something more like speed cruising.  Rocketing down the backroads, he straddles anything that could be alive, then rapidly backs up for a better look.  It’s efficient and effective, but for someone like myself who can get motion-sickness sitting in a parked car, it’s a bit of a challenge.  I tried to focus on scanning the pavement for movement as we zipped along.  It was a good distraction, but no replacement for getting out into the fresh air.  

The streamside salamander (Ambystoma barbouri)

After a few stops to inspect peepers, wood frogs, and spotted salamanders, there, stretched across the pavement—a salamander I had never seen before.  Upon closer inspection, nothing was particularly striking about this unassuming salamander.  Its body was chunky, though smaller proportioned than a spotted or a jefferson.  It displayed no bright colors or distinct markings; two shades of light gray frosted its back and sides.  The head was held high, peering up at us—an unusual behavior for this stubborn species.  Its head was also disproportionately small and snub-nosed, at least for a member of the “logger-headed” mole salamanders.  A thin, yellow line stretched across its rounded face—giving the salamander a content smile.  

“That’s our barbouri,” Carl commented as he looked down at our find.  Ambystoma barbouri, the streamside salamander.  Streamsides are unique among mole salamanders—not for their appearance, but for their behavior.  They don't breed in the temporary vernal pools that other members of this group migrate to every spring or fall.  Instead, their courtship and egg laying takes place in shallow headwater streams.  They attach their eggs to the underside of flat stones, and after hatching, the larvae grow and develop in these streams.  A. Bourbori occupy a limited range in southwestern Ohio and other nearby states where they inhabit upland forested hillsides during the summer.  

Travel just a few counties north of the streamside’s range, and you might encounter a salamander that looks nearly identical.  Until as recently as 1989, the streamside salamander was thought to be a stream-dwelling form of Ambystoma texanum, or the small-mouthed salamander.  Small-mouthed salamanders differ in appearance from the streamside in a few unremarkable ways.  They have a slightly longer snout, unique dentition with two rows of teeth, and a more wedge-shaped tail.  The most important behavioral difference is that small-moutheds breed in vernal pool habitat like the rest of the mole salamanders.  It is thought that about 4 million years ago, these two species split when A. barbouri began utilizing stream habitats.  However, breeding behavior is not a sure-fire way to tell these species apart, as both texanum and barbouri have been reported utilizing both streams and pools.

The following night, Carl and I traveled an hour north of Athens.  On a short stretch of road that cut through a patch of forest between a cornfield and tiny town, Carl spotted a single small-mouthed salamander.  Another lifer for me.  Small-moutheds inhabit lowland forests, floodplains, and fields.  If I hadn't known differently, I never would have made the distinction between this individual and the salamander from the night before. 

The small-mouthed salamander (Ambystoma Texanum)

This classic case of a cryptic species is made even more confusing by the genetic netherworld that these salamanders emerge from.  The more widespread and abundant Small-mouthed salamander (found from Ohio to Texas) is commonly parasitized by the ambystoma unisexual complex.  This group of all-female salamanders actually steals genetic information from other salamander species and incorporates it into their polyploid (more than two sets of chromosomes) genome.  This can result in animals that look quite like small-mouthed salamanders but who don't belong to the species and who might also contain the genetic information of blue-spotted salamanders and even tiger salamanders.  

In areas where A. texanum and A. barbouri overlap, some interbreeding, either historically or on going, is thought to occur.  This can blur the line between these two species and endanger the unique genetic identities of each (particularly A. barbouri due to its much smaller population).  To determine range maps where different species live, genetic testing is often helpful when dealing with cryptic species.  

When it comes to barbouri and texanum, however, genetics is another hurdle herpetologists must overcome.  The interbreeding that has taken place between these two species has left its signature in the genes of some A. texanum.  This phenomenon is called mtDNA introgression.  Mitochondrial (mt) DNA is inherited from the mother, and doesn't change much from generation to generation.  This makes it important for determining unique species lineages.  What's so difficult for this species in particular, is that entire populations of small-mouthed salamanders possess the mtDNA of streamside salamanders left over from interbreeding events.  Individuals with this condition can still be told apart by their anatomy, but this often requires collection or dissection, something most herpers aren't prepared or willing to do.  

The small-mouthed salamander we found on the second night was from a population that possess the mtDNA of the streamside salamander.  While this lends some question as to the true identity of these salamanders, the population is continuous with the known small-mouthed range.  For this reason, as well as anatomical features, we are comfortable calling them true small-moutheds.  This really shouldn't be the stopping point, however. Countless more questions need to be asked in order to expand our knowledge and better our understanding of these unique and unusual creatures. 

Even when they seem dull or indistinguishable, herps often hide some baffling secrets.  Salamanders are funny that way.  These slimy puzzles force us to think outside of what's familiar and comfortable.  I think that's why they fascinate me so much.

Road Cruising

The moon loomed overhead, its round face stained an unusually deep shade of nectarine orange. Mist rolled off the wet asphalt, parting like the Red Sea in my high beams.  The low hum of my car’s engine and the soft static of the radio added to the feeling of silence.  I rolled along at 15 miles per hour, eyes darting to each crack in the pavement, every stick, every rock, every dark blotch of tar.  My foot was poised to slam on the breaks at the first sign of movement.  I was road cruising. 

Always stop for "snakes!"

If you have never searched for reptiles or amphibians, then road cruising likely has little meaning.  For a herpetologist, however, road cruising provides a chance to see some amazing things.  The warm, uniform surface of roads entices ectotherms to bask and makes them easier to spot.  Driving covers more ground in less time compared to hiking, increasing the chances of a reptillian encounter.  

Road cruising is, however, a double-edged sword.  One of the leading causes of reptile and amphibian mortality is from collisions with vehicles.  Herps are often too slow to escape speeding traffic resulting in the deaths of adults, juveniles, and hatchlings.  For threatened or endangered species, the effects of roads can be particularly devastating.  Animals that are not killed by the road are often isolated from other populations due to habitat fragmentation.  To make matters worse, misunderstood animals such as snakes are often intentionally hit by ignorant drivers. 

A northern ring-necked snake.

Given the right location and conditions, road cruising can be a fruitful pastime for any wildlife enthusiast.  With a little knowledge of the right habitat (and often the right weather), a herper can expect to see everything from salamanders to turtles, frogs, and snakes.  

I often spend my evenings driving back roads, searching new locations from residential areas to state forests.  Reptiles and amphibians are unpredictable; they could turn up anywhere.  For amphibians, rain is almost always necessary.  Early spring ushers in the breeding season for many frogs and salamanders.  During amphibian migrations, the number of animals on the road becomes so dense that road cruising is no longer an option.  

Snakes, on the other hand, like hot, humid nights (rain seems to keep them off the roads).  Turtles travel to lay eggs during the spring and can commonly be seen lumbering across busy roadways during the day.  Night, however, is the best time to search for most herps.  Cooler temperatures draw these cryptic creatures out of their hiding places to hunt or bask. 

Photo courtesy of Brad Prall.

When driving, I keep my speed between 15 and 20 mph—any faster and I risk fatally missing something.  Knowing what to look for helps immensely.  Learning the patterns and habits of native species can improve the chances of spotting them.  Being able to distinguish scales from leaves or sticks is also helpful.  I have lost count of the number of times I have stopped for branches, bungee chords, or old pieces of tire.  However, it is always better to mistake something for an animal than miss one when it is actually there.  

Some of my best trips searching for wildlife have been thanks to advice from others.  Fellow snake enthusiast Brad Prall informed me of a location where he had seen nine copperheads, a dead timber rattlesnake, and a black ratsnake during a single night of road cruising.  He graciously answered my questions and helped me set up a route for my search.   

On one brutally hot July day (reaching the mid-90s), I prepared to drive the two hours down to the location.  I was accompanied by my fellow field technicians Aspen Wilson and Tyler Stewart.  Aspen, a Plant Biology major, and Tyler, a Wildlife and Conservation major, were working for Garrett Sisson, tracking his animals during the summer field season.  Upon mention of Brad's nine copperheads, they eagerly agreed to join me. 

As we approached our destination, my GPS directed (in its robotic female voice),“turn left onto The Road.”  Three college students, searching for venomous snakes, in the woods, in the dark, on an unnamed road.  I chuckled at how foreboding this was going to sound.

The first snake of the night was a DOR—dead on road—rough greensnake.  I had never seen a live greensnake in the wild and was disappointed to find one crushed.  Dead or alive, it was a snake; we were in the right habitat.  I crept down the paved road, foot hovering over the brake.  We all sat hunched forward, awkwardly peering into the night, expecting to see a serpentine figure around every bend, just beyond the high beams.  

Aspen holding an American toad.

As we continued on our way, something little and fat lit up in my lights.  “Is that a toad?”  I asked.  “That’s a toad,” we all confirmed in unison.  I pulled the car to a quick stop and we all hopped out for a closer look.  As I began to usher the little amphibian off the road, something enormous snorted behind me.  My first thought was big dog.  “Horse!” cried Aspen.  As I spun around, my headlamp illuminated a fully grown chestnut-colored stallion.  I stood just inches from its pen, separated from the road by nothing more than a thin black wire.  We made a beeline for the vehicle.  Being alone in the dark with a startled horse—well, you get the idea.  

As we sped away, I laughed, “we are out here to find venomous snakes and a horse is the reason we are going to die.” 

Then we saw it.  A little more wiggly than a stick.  A little more reflective.  Three doors flung open at once.  We approached quickly but cautiously, not wanting to startle the snake into a retreat.  It was a little copperhead, about a foot in length.  Aspen gently placed a net over the snake, allowing it to curl up defensively.  A baby copperhead's head is almost comically too large for its skinny body.  The snake's round, jewel-like eyes looked up innocently as if to say, “Who?  Me?”  

As I knelt down to photograph the snake, another car pulled up behind ours.  “What is it?” called a voice.  “Copperhead!” I called back.  A man walked into the light; it was none other than Brad Prall himself.  “Oh excellent!  I’m so glad you guys found something!” he said enthusiastically. We promptly introduced ourselves and shook hands.  Brad had been cruising this site for years, and a nicer fellow you will not meet.  He eagerly told us of good roads we should check, and was thrilled to hear about the reptile research we were involved in.  

The temperature had dropped quicker than expected, but still remained in the 70s.  Brad decided to head home and return the following night, remarking “75 and humid is when we have the best luck, but you should still find some good stuff in the lower 70s.”  Enthusiastic and knowledgable people like Brad make it possible for young herpers like myself to discover new and exciting creatures.  I was glad to be able to thank him in person.

That night we found a total of five small copperheads, all around a foot in length (one was sadly DOR).  We also found a little ring-necked snake and an eastern garter snake.  It was by far the best luck I have ever had road cruising!  We left for home around midnight, anticipating returning to this spot in the near future.