Wind-swept Rattlesnakes

It was overcast.  Thinly veiled streaks of formless, gray-blue clouds stretched to the horizon.  The rapidly warming day was quickly approaching the perfect basking conditions that I’d been waiting for all morning.  I was feeling optimistic and energized.  The spring semester had just finished and I’d soon be heading to New Hampshire for a position at the Hubbard Brook Experimental Forest in early June.  That meant I had all of May at my leisure to pursue wildlife.  I wasn't about to waste a single minute that could be spent birding or herping.  

As I approached my destination, twenty five mph winds began to pick up.  The bare branches of trees and newly-emerged roadside greenery swayed and creaked as I gripped my steering wheel to steady myself.  Wind is generally not a friend to wildlife watchers.  It keeps the birds away and the herps under cover.  Old trees, aptly named “widow makers,” are of real concern.  Luckily, I was headed to one of Ohio’s last remaining Prairie remnants in Northwestern Ohio where the sparse trees pose little danger.  What I was there to look for, however, is another story entirely.   

I parked along a gravel ditch just as a small tree shuddered and gave way across the street.  The wind whipped across the open landscape, rustling through the grass as though hundreds of snakes were sliding all around me.  I suddenly began to understand the overwhelming sense of dread that ophidiophobes must experience when encountering a snake.  I strapped a pair of protective gaiters around each of my ankles.  There could be a concealed rattlesnake below any tuft of grass, and I wouldn't be able to see it or hear it over the gales.  

I’ve looked for Ohio’s two endangered rattlesnake species many times, but the smaller of the two has always eluded me.  Eastern Massasauga Rattlesnakes (Sistrurus catenatus) inhabit the wet meadows, bogs, and mesic prairies from New York to Ontario and as far west as Iowa and Missouri.  In Ohio, they were once considered commonplace across most of the glaciated half of the state.  Direct persecution, habitat loss, collection, and road mortality have reduced their 28 county range down to just nine remaining counties.  The eastern massasauga faces similar declines across eastern North America.  These snakes were recognized as nationally imperiled in the 70s and are thought to be extirpated from 40% of their original localities.  

Eastern Massasauga Rattlesnakes inhabit lowlands during the spring and fall, relying on crayfish burrows for cover and hibernation sites.  Water just below the surface that never freezes is a must.  If the frost layer penetrates the ground, the snakes will not survive.  Loss of suitable overwintering habitat or modifications to the water table quickly decimates massasauga populations.  Ohio alone has lost 90% of its original wetland habitat.  These snakes persist in landscapes that pose particular difficulty to agriculture, and were subsequently left relatively unchanged.

Uplands are just as important to massasauga ecology.  During the summer months, snakes move into upland forests to forage.  These landscapes are often unprotected or heavily developed, resulting in population declines even when the adjacent wetlands are protected.

With each step, water bubbled up through every crack and burrow in the mud.  I hadn’t walked one hundred meters from my car when I froze. Sitting coiled in a tight bun atop an elevated pile of dry prairie grass was a massasauga rattlesnake.  My heart raced as I took a few steps back and freed my camera from my pack.  I crept around the motionless rattlesnake, it’s dark body burning into my retinas.  Upon closer inspection, it became clear that this snake was not black, but tan with dark brown blotches; its triangular head and unblinking eyes were clearly visible through the tall grass.  Stretched out, the sauga would probably measure over two feet (these pigmy rattlesnakes max out at just under three feet).

I kept a respectful distance, well outside of the snake’s strike range, but I still didn’t want to startle the sleeping viper.  As I moved for a clearer shot of the head, the snake suddenly became aware of me.  Striking or even rattling unless thoroughly provoked is almost unheard of.  Massasaugas typically remain motionless, allowing the threat to pass by unawares.  Perplexing, the massasauga twitched in agitation with an almost copperhead-style movement as it coiled its neck and raised its buzzing tail.  I was shocked.  I’ve encountered timber rattlesnakes at closer range and never had one so much as tongue flick.  I stepped away, allowing the snake plenty of room to escape.  Butt still buzzing, the sauga slipped below the tangles of grass and out of sight.  I suddenly felt very glad I was wearing gaiters.  

I am confident that this uncharacteristic encounter was down to individual personality.  Carl Brune often tells the story of two eastern hog-nosed snakes he hatched from eggs.  One sibling would play dead whenever approached, while the other would only flare its hood and hiss.  Snakes are as much individuals as you or I.  

During the course of my search, I encountered three more massasaugas.  Two never budged as I watched and photographed them.  The third was found out on the crawl, and while it did coil up upon my approach, it never rattled or gave the faintest impression that it felt threatened.  After a few minutes, it slowly turned away and drifted off into the tall grass.  

After that first encounter, I was primed to be a bit jumpy.  I was scared half to death when a snake came lunging out of the tall grass in full strike, mouth agape.  After the initial shock wore off, I looked down to see a large, but utterly harmless, eastern gartersnake.  “What are you doing??” I said aloud, holding back laughter.  I plucked the grumpy garter from the grass and placed him off the trail.  Snakes, venomous and nonvenomous alike, have no interest in biting if they don’t have to.  All they want is to be out of harm's way.  Sadly, senseless killing by ignorant or fearful snake-haters continues.  It is not unheard of to discover a dead sauga with its rattle cut off—as a trophy.

Even where massasauga populations appear stable, a new threat has emerged on the scene.  In 2006, a fungal pathogen called Ophidiomyces ophiodiicola was discovered in Timber rattlesnakes.  This fungus targets wild and captive snakes, primarily rattlers and colubrids, in eastern North America and Europe.  It penetrates the epidermis though any small wound and causes lesions and blisters to form across the snake's head and body.  The origin and dispersal mechanism of this fungus are unknown, but it can survive in the environment without a host for some time.  Whether this fungus was introduced or a native turned virulent, it appears to work in tandem with other environment stressors like habitat modification and climate change.  Some snakes may be able to shed repeatedly to keep the fungus at bay, but many succumb as the infection attacks the deeper layers of skin, muscle, and bone.  Massasaugas are particularly vulnerable to this Snake Fungal Disease, and their already dwindling populations are being pushed closer toward extirpation by its spread.

I've visited many historical localities where the tufts of wiregrass and crayfish burrows no longer harbor wild massasaugas due to poaching and habitat modification.  Without their swamp rattlers, these wet meadows, fens, bogs, and prairies feel eerily empty.  It would be an irreparable shame to see the littlest of Ohio's vipers disappear from its final strongholds.

Thanks for reading!
Keep living the field life.
Ryan

An "Aberrant Eastern Gartersnake"

Plains gartersnakes (Thamnophis radix) are a common species from south central Canada through the Great Plains to Texas and Oklahoma.  Across this expansive range, their populations can reach densities of 300 individuals per acre.  They are not a rare snake by any stretch of the imagination.  In Ohio, however, the entire range of this species is restricted to just one county within one prairie remnant (and not even the entirety of that).  Ohio plains garters are snakes out of time.

5,000 years ago, the climate in Ohio was very different than it is today.  The Xerothermic period, as it is called, was significantly dryer and hotter by as much as five degrees Celsius with 25% less rainfall.  For several thousand years, Ohio’s climate closely resembled modern day Kansas.  This warm, dry period was marked by an expansion of western biota into the state.  Flora and fauna that we associate with the great plains, found suitable habitat in this “prairie peninsula.”  When the climate shifted again (to the cooler, wetter present), the prairies receded, leaving behind a few isolated prairie pockets where clay soils inundate the landscape for much of the year (such as on ancient riverbeds), preventing the expansion of forests.  Today, agriculture has reduced the 12,000 ha of contiguous wet prairie across northwestern Ohio to a few thousands disjunct hectares.  

The entire Ohio Plains Garter population is so localized that these snakes were not verified in Ohio until 1945.  Even the great herpetologist, Roger Conant, who collected the first specimen in 1931, mistook the washed-out DOR (dead on road) snake for an “aberrant eastern gartersnake.”  This is the ultimate case study in local abundance.  While these snakes would have originally inhabited a larger expanse of the available prairies in Ohio, habitat loss and land-use changes have reduced their already limited populations by as much as 94% in some areas.  Where they still occur, there can be hundreds per acre.  However, the sympatric eastern gartersnake (Thamnophis sirtalis sirtalis) outnumbers the plains by about ten to one.  If I had any hopes of finding a plains, each and every striped snake I discovered would have to be thoroughly examined.

A terrestrial crayfish burrow 

In preparation for a long week of finals, my girlfriend, Julia Joos, and I decided to take a weekend herping trip to unwind.  We arrived in northwestern Ohio in the evening, anticipating an early morning search the following day.  The weather, however, had other ideas.  That night brought storm clouds and frigid temperatures that stuck around until late afternoon.  The clouds finally burned off just a few hours before sunset.  We hoped the timid sunshine and mild temperatures would be enough to entice the snakes to bask. 

The flat expanse of fields and croplands intermitently bisected by roads might not look like much to the passing observer, but I could tell right away that this habitat was great.  Hollow mud chimneys—the entrances to the burrows of the terrestrial crayfish species Falicambarus fodiens—were everywhere.  These burrows are not only a sign of high water quality and good soil chemistry, they also provide the snakes with refugia during inactive times of the day and year.  Modify the water table or introduce pollutants that wipe out the crayfish, and the snakes will invariably disappear along with them.  

In early spring, the vegetation is still brown and brittle, weighted down from months of snowpack.  With their lateral stripes, gartersnakes camouflage perfectly among the criss-crossing network of dried reeds.  I hiked quickly, scanning the ground and listening for rustling movement.  Julia was more careful.  She found the first snake of the day in a spot I had tromped right over.  It was an eastern gartersnake, still muddy from the crayfish burrow it had recently emerged from.  During the next hour, we found half a dozen more garters, but none were quite what we were looking for.  I finally resolved to photograph one of the more colorful individuals coiled up among the mud and grass.  As I set up my camera, Julia called out from just over my shoulder.

“Oh, here’s another one!” she said.  I turned around to see a large gartersnake coiled among the grass.  “Nope!” I laughed, “that’s our radix!”  Had I not been looking for the subtle defining characteristics of the plains garter, I easily could have passed this snake by.  Even through the snake’s mud-dusted scales, I could tell its stripes were unusually black.  The dead giveaway that this was our plains garter, however, was the yellow-orange stripe running the length of the garter’s back.  Out of the hundreds of variations of the eastern gartersnake that I have seen over the years, none have had a stripe quite that color.

The garter cooperated nicely, coiling in front of us and tongue flicking.  After a few shots the snake decided it had had enough, and zipped away through the grass.  The purpose of those stripes becomes clear when a garter flees through a vegetated landscape.  longitudinal stripes make it significantly harder to judge the snake's speed, length, and direction.  The plains garter seemed to almost meld with the landscape it so depends on. 

A juvenile plains gartersnake (Thamnophis radix)

On a return visit to the area a few weeks later, I was lucky enough to find a juvenile plains gartersnake, a good sign that these endangered snakes are breeding.  Despite the perilous predicament these snakes find themselves in, very little management is directed towards their conservation.  Reintroduction efforts through captive breeding have been underway for years, but these snakes still face a host of threats in their final stronghold.  The landscape they call home is primarily managed for waterfowl hunting.  Scheduled mowing of their field habitat has been shifted to coincide with snake inactivity, but individuals are still occasionally killed.

Like that first specimen found by Conant in the 30s, road mortality is one of the easiest ways to discover this species.  I found a large adult T. radix, carelessly crushed by a speeding vehicle as the harmless snake attempted to cross between habitat patches.  Even though plains gartersnakes are common across the great plains, the disjunct populations in Ohio, Missouri, and Illinois all represent unique genetic lineages.  They are important contributions to the biodiversity of our state and to the persistence of these remaining prairie patches.  

Overwhelmed with Frogs

Lesser Treefrog (Dendropsophus minutus)

It hasn't been so much writer's block that has kept me from posting about my favorite feature from my stay in Ecuador, I just haven't been able to decide where to begin.  Ordinarily, I’ll drive for hours and make dozens of trips in search of new (to me) species.  In my home state of Ohio, there are only 80 species of native reptiles and amphibians.  Each new find feels that much closer to seeing them all (a dream I’ve had ever since I was young).  Finding all eighty might still seem like a lot of time and effort—and it is—but it’s a challenge that’s just on the periphery of reasonable.  With enough dedication, I can add a new species every few months (if I’m really lucky, multiple in a single trip!).  In the tropics, this ratio is blown way out of proportion.  Ecuador is home to 350 species of reptiles and 460 species of amphibians.  During a week long stay, you might see 80 or more species without much effort.  Add in a guide that knows what they’re doing, and your species list could easily reach the hundreds.  

So what’s the problem?  With so many species to see, the tropics can feel inaccessible to the average naturalist.  Don’t think I’m complaining, though.  As a wanna-be biologist, I value biodiversity over my own two legs.  Ecuador covers only 109,483 square miles (for comparison, the US covers 3.797 million square miles).  It’s remarkable that there are still places on earth that boast such a unique variety of species in such a small area.

Marbled Treefrog (Dendropsophus marmoratus)

But how are you supposed to build a reasonable biological picture of such a diverse area in a limited amount of time?  Even with the most recent field guides, there is always the chance of stumbling upon something no one has ever seen before (it is estimated that nearly 200 species of frogs have yet to be discovered in Ecuador).  More likely, however, is the chance of stumbling upon something no one has ever bothered to put in a field guide.  In the end, you might not know what you have.  Cryptic species complicate things further.  Two or more frog species may look indistinguishable unless you directly observe their calls (or sequence their DNA).

Dwarf Clown Treefrog (Dendropsophus bifurcus) 

When a night hike down a forested road turns up something new every five minutes, it's impractical to spend an extended amount of time observing any one animal.  While I want to see as many herps, birds, and what-have-yous as I can, I’m no life lister.  I don’t just want to check off each species and move on to the next challenge.  I want to see each creature intimately to try to understand it better.  

As I have discovered more and more of Ohio’s reptiles and amphibians, I’ve had to relearn just about everything I thought I knew about the herps of my home state.  Each discovery has allowed me to weigh everything I’ve read or assumed about a species against what I have directly observed in nature.  It’s all about subverting my expectations.  With so many tropical species, I never really know what my expectations should be in the first place.  Each find is exciting, but also a little jarring, “Oh! Didn’t realize you existed!”

Red-skirted Treefrog (Dendropsophus rhodopeplus)

To avoid this problem of “overabundance of species,” I have tried to place my discoveries into categories, namely Family or Genus.  This gives a wider context that (for me) makes tackling the superabundance of Ecuadorian frogs and toads a little more manageable.  I have done my best to ID each of the species I photographed, but many are still up for debate.  I am no expert and any suggestions are greatly appreciated.

Crested forest toad (Bufo margaritifer)

I will begin with the family Bufonidae.  I was on such a high that first night at the research station that you might have assumed I was running around licking toads instead of photographing them.  It was thrilling to watch my fellow biology students join in with equal levels of enthusiasm, referring amusingly to our group herping as “The Hunt.”

Crested forest toad (Bufo margaritifer)

The Bufonids are the true toads, locally represented in Ohio by the ubiquitous American toad (Anaxyrus americanus).  Tropical bufonids share the warty skin and earth tones, but many species are much more regal in their head adornments.  The Crested Forest Toad (Bufo margaritifer) is commonly encountered hopping across the forested trails.  These toads are extremely variable; some express slight ridges along their craniums, while others show exuberant crests extending above their eyes and nostrils.

The toads don’t just get fancy in the tropics, they get big too.  The Marine or Cane toad (Rhinella marina) can grow over eight inches in length and weigh nearly four pounds.  We discovered one of these behemoths the very first night, hopping confidently across the pavement beneath our dorms.  They have been introduced to many parts of the world and are driving native amphibian populations extinct by outcompeting and eating local frogs.  It was refreshing to see them in their natural habitat where they belong.

Marine Toad (Rhinella marina)

Then, of course, there are the treefrogs.  Treefrogs belong to the family Hylidae, the largest group of Amazon frogs.  Most of these frogs are distinguished by their enlarged toepads which allow them to scale foliage and buildings with ease.  Their shear diversity makes them challenging to identify.  This is complicated further by the fact that many species change color pattern from day to night.

Three hundred species represent the genus Hyla worldwide (of which, the gray treefrog of Ohio (Hyla versicolor) is a member).  Most species in this genus are arboreal, nocturnal, and posses webbed feet.  In 2005, many common Amazon treefrog species were split off from Hyla and placed in their own genus Dendropsophus based on their number of chromosomes (many of these species are pictured in the intro to this post).

Giant Broad-headed Treefrog (Osteocephalus taurinus)

There is the bizarre treefrog genus Osteocephalus: the Bromeliad or Broad-headed Treefrogs.  The skin on the head of these frogs is actually fuzed to the roof of the skull, giving them a distinct, flat-headed appearance.  They are a wary group, leaping away from the slightest disturbance.  They breed in the shallow pools that collect in the flower cup of bromeliads.  The radiated irises of the Giant Broad-headed Treefrog (Osteocephalus taurinus) are mesmerizing.  

White-lined Leaf Frog (Phyllomedusa vaillantii)

My favorite treefrogs belong to the genus Phyllomedusa: the Monkey frogs.  Elongate limbs that bend at sharp angles and opposable thumbs allow these frogs to spread waxy secretions across every inch of their bodies.  These secretions act as a kind of sunscreen, helping to prevent desiccation. Their movements are slow and methodical, very unlike many of the other rapid, nervous frog species.  The eery stillness of these frogs is almost ghostly when illuminated in the light of a headlamp.

Veined Treefrog (Trachycephalus typhonius)

While photographing one particularly bizarre species of Caque-headed Treefrog in the genus Trachycephalus, the veined treefrog (Trachycephalus typhonius), I noticed something sitting along the branch a mere inch from the frog's enlarged toepads. Shining the branch with my flashlight, I was baffled to find a salamander.  Amazon climbing salamanders (Bolitoglossa altamazonica) belong to the family Plethodontidae (many of our North American species belong to this family too).  Unlike North American species, on humid nights, these salamanders scale vegetation up to six feet high.  They sit motionless, apparently doing nothing for hours before returning to the leaf litter by morning.  

Amazon climbing salamander (Bolitoglossa altamazonica)

The family Leptodactylidea was a mixed bag.  A few species, like the enormous Smoky Jungle Frog, struck me as very familiar.  It could practically have been a leaf-colored bullfrog.  Later, I was shocked to learn it is one of the more toxic species in its range.  These jungle frogs belong to Leptodactylus, a genus containing around 55 species, most of which are moderate to large frogs.  Some species are so toxic that just holding them can cause a burning sensation on the skin (which was duly noted when I caught a large Smoky Jungle Frog the first night).  

 Smoky Jungle Frog (Leptodactylus pentadactylus)

Other frogs in this family, such as the Painted Forest Toadlet (Physalaemus petersi) were like nothing I had ever seen.  These toadlets were speckled with little red lesions that almost made them look diseased.  Otherwise, they were cute, little frogs that held their heads erect, giving the impression of an opposable neck.  

Painted forest toadlet (Physalaemus petersi)

Another member of Leptodactylidae and the only member of its genus, the Painted Antnest frog (Lithodytes lineatus), is a poison-arrow frog mimic.  Their pattern of brown with light yellow stripes is almost identical to Allobates femoralis.  This is a case of Mullerian mimicry.  Both species have converged on a similar coloration because it turns out the Painted Ant-nest frog is also toxic.  They live in the mounds of leaf-cutter ants, fending off attack with noxious skin secretions.  

Painted Antnest frog (Lithodytes lineatus)

The Microhylids, or narrow-mouthed toads are represented in the tropics by a handful of species.  Here they are commonly referred to as "sheep frogs."  These small frogs grow scarcely longer than an inch.  

Sheep Frog Species (Elachistocleis sp.)

If you’re a herper, you might be wondering, “did he see any dendrobatids?”  Dendrobatidae is the family that includes the poison-arrow frogs.  The short answer is yes.  For a while, however, I thought I was going to have to pretend I hadn’t to save face as a photographer.  

I actually saw three poison arrow frogs.  All were the same species: the Ecuadorian Poison Frog (Ameerega billinguis). These frogs are tiny.  The tropics are home to a lot of tiny frogs, but these frogs are really tiny.  I mean fit-on-your-fingernail tiny.  To escape, all these frogs have to do is hop once.  Their red back and yellow-spotted legs allow them to instantaneously disappear among the decaying red and yellow leaf litter.  I could be staring directly at the frog, ready to snap a photograph, and a single spring would mean I had to find it all over again.  This was the one frog family I felt I needed to photograph (I was even presenting a talk for the class on their family) but for most of the trip, it looked like I was going home empty handed.  It wasn't until our group teamed up with the local Wairani guides that my moment finally came.  

Ecuadorian Poison Frog (Ameerega billinguis)

Nange (pronounced Nahn-gey), the village chief, spotted the frog.  He spoke no English, and I no spanish (or Wairani for that matter) but he knew I wanted to see the frogs.  He beckoned for me to come over and pointed out the minute frog sitting innocently among the leaf litter, its throat fanning rapidly.  We positioned ourselves to make the capture.  The frog hopped and was instantly gone.  I groaned, certain the little amphibian would not reappear.  A moment later, the frog hopped back into view and I was able to grab it (and a decent amount of the surrounding leaf litter) and hand it to Nange.  

Ecuadorian Poison Frog (Ameerega billinguis)

Nange placed the frog in the middle of the trail for me to photograph.  I got some delightful shots, emphasizing the little amphibians gorgeous color pattern and texture.  When I returned home after our two weeks, I immediately downloaded my 5,000+ photos.  I had taken so many images that my computer’s hard drive filled up.  To make room as quickly as I could, I deleted the photos I had already imported from my chip.  Once that was finished I started scrolling back through the two weeks and that’s when DISASTER struck.  My computer had glitched when the hard drive had filled up, and the images of my poison arrow frog (and only my poison arrow frog) had been deleted.  

I was horrified to say the least.  Months passed and I couldn't bring myself to write anything about the amphibians without my crown jewel.  “You’ll just have to go back one day and photograph another,” I tried to tell myself.  Inexplicably, when going back through my photos last week—wallah! Unharmed on the screen in front of me: my poison arrow frogs.  I don’t know what cosmic force took pity on me, but I’ve never been so relieved.  

Even though my poison frog photos turned up, I am still certain I need to return to Ecuador and the Amazon Rainforest.  There are so many more frogs to see after all.