Tuesday, July 23, 2019

Fires, Fields, Turtles, and Trees

“Do you have muck boots with you?” Todd asked.  I kicked myself.  When packing for my Magee Marsh trip, I had neglected to bring either my boots or waders.  Would they be necessary to look for snakes, I inquired?  “Depends on whether you want to see spotties or not,” he said with a winky emoji.  My eyes widened and my pace quickened.  I hadn’t even considered looking for spotted turtles.  Finding my first Blanding’s turtles (and a mating pair at that) had seemed like a dream come true.  Now I was confronted with an opportunity so good I couldn’t pass it up.  Luckily, Todd had a pair he could lend me.  I raced back to my car, leaving the birds behind (again).  

Todd was out front loading his van as I arrived.  His open trunk was filled with boots, aquatic measuring equipment, and books from recent trips afield.  A wetsuit hung drying on his back fence near a sign that designated his garden the winner of the “best native wildflower planting.”  As a lecturer at the University of Toledo, Todd is an educator at heart.  His hands-on, in-your-face enthusiasm is contagious.  


Spotted turtle Oak Openings
The complexities of the ecosystem are what really get Todd excited.  He has managed everything from wet prairies and watersheds to local fish species and endangered mussels.  Todd was an excellent guide through the unfamiliar (to me) landscape of northwestern Ohio, pointing out fascinating hydrological phenomena and natural history at every turn. 

“See that field?” He gestured to a small woodlot along the road no bigger than my suburban backyard.  Widely spaced trees allowed a dense understory of vegetation to grow.  “Over 30 state listed plant species can be found right there,” he said.  

Most wouldn’t think of Toledo as a land of extremes—or that some of the rarest ecosystems on earth sit just west of the city.  Stretching over 180 square miles across three Ohio counties (and one Michigan county) the Oak Openings is perhaps the most unique part of the state.  Here, vast sand barrens intersperse with mesic prairies and oak flatwoods.  As many as 145 state listed plant species have been recorded from the Openings, including our only native cactus (Opuntia humifus).  

Rare plants and wildlife in the Oak Openings
Wild Lupine (Lupinus perennis), a rare Ohio plant found only in the Oak Openings.
These rare ecosystems are maintained by annual cycles of extreme wet and extreme dry.  The secret lies in the sand.  The Oak Openings look as if someone dropped a little piece of the Mojave Desert into Ohio.  These rolling dunes are actually ancient sandbars, first deposited by a late-glacial precursor to Lake Erie between 11,000 and 9,000 years ago.  The sand can be 50 feet thick in some places, obscuring another important geologic layer: the till.  This impermeable clay holds any water that soaks through the porous sand.  Oak forests grow in uplands where the sand is thick and dry, while emergent open-canopy wetlands form where the till sits just below the surface.

The need for boots was immediately apparent as Todd and I stepped off the road.  The trail quickly opened up into a wide expanse of whispering Bluegrass, submerged in ankle-deep water.  We sloshed along, peering intently into every grassy hummock, hoping to catch the inky glint of a yellow polka-dotted shell.  Spotted turtles don’t typically bask on exposed logs like the more common painted turtle.  Instead, they bask nestled among vegetation, slipping into the shallow water at the first sign of trouble.  When the wetlands dry up by late summer, a complex network of underwater turtle highways are revealed.  Turtles not traversing their typical routes disappear into the muck without a trace, making them near impossible to find—unless you’re lucky enough to step on one.  “If you feel a rock beneath your foot,” Todd said, “it’s not a rock."

Where to see spotted turtles in Ohio
A female spotted turtle.  Note the pinkish-orange chin.
Once a common species throughout the state, spotted turtles (Clemmys guttata) have declined across the east coast and the Great Lakes region.  Ohio has lost close to 90 percent of its original wetlands, including most of the suitable spotted turtle habitat.  These turtles rely on wetlands to overwinter, moving into upland woods by late spring and summer.  The prime time to look for spotties is April and May while they are still basking near their aquatic hibernacula.  Once the temperatures start to heat up, these turtles become harder and harder to find as they spread out into the surrounding landscapes.

Todd called to me from several yards away.  I ran as best I could through the ankle-deep water, heart pounding at the thought of my first spotty.  Todd had bumped a small female with his boot, exposing the turtle’s hidden basking spot within the grass.  Held firmly but gently in his hands, the little turtle didn’t seem the least bit concerned.  She looked around bright-eyed and curious, legs waving as if walking in slow motion.  I was immediately struck by just how tiny this turtle was; she could fit comfortably in the palm of my hand.  Adult spotted turtles max out at around four inches in carapace length, making them one of our smallest native species.  
Threatened spotted turtle in Ohio

I was beyond delighted.  We took copious photos before releasing her back into the shallow water.  An hour later, I stumbled upon another, larger female basking out in the open.  We could tell these turtles were female for two reasons: one, the classic flat belly (males have a concave plastron) and two, her chin was a soft pinkish-orange.  Male spotted turtles have a much darker black or brown chin. 

As we half hiked, half sloshed our way back towards the vehicle, my foot brushed something hard.  Looking through the vegetated water, I was just able to make out a strip of bone nestled in the sediment.  My mind jumped to the sun-bleached shells of long-dead box turtles and snapping turtles that I’ve been lucky enough to stumble upon in the past.  I flipped the object over and was surprised to find a black plastron.  I knelt and plucked the small shell from the water.  Surprise number two: clenched between my thumb and index finger, a very much alive spotted turtle squirmed for freedom.  The large, keratin scutes that normally cover the animal’s back had completely fallen off, revealing the smooth bone beneath. 

Spotted turtle missing scutes due to fungus
A male spotted turtle missing the scutes along its back
It is unclear just what would could cause this kind of bizarre and dramatic disfigurement in a spotted turtle's shell.  It is possible this turtle survived being caught in a controlled burn that scorched just the outer layers of keratin and left the rest of the animal unharmed.  Alternatively, it could be suffering from some other physical trauma, exposure to toxins, malnutrition, or a bacterial or fungal infection. The fungus, Fusarium semitectum, is known to cause skin lesions and scute necrosis in desert tortoises.  Regardless of its ultimate cause, this deformity is symptomatic of many larger issues impacting the habitat these turtles call home. 

"A few years ago, this whole wetland would have been overrun with buckthorn," Todd explained.  Despite its natural appearance, the Oak Openings is anything but pristine. Human impacts are evident everywhere you look.  Settlers cut down the old growth oak stands and drained and channelized the groundwater in an attempt to farm the sandy soil.  Agriculture proved unprofitable, but the damage was done. As the surrounding areas developed, suppression of fires and a lower water table transitioned many natural openings into closed canopy forests. Even where the ground held enough water to exclude trees, introduced plants like buckthorn and cattails turned the once diverse fields of grasses, sedges, and rushes into mono-cultures. 

Intensive management is now necessary to maintain the Oak Openings’ unique ecosystems.  A strict regimen of selective cutting, herbicide use, and prescribed burns are integral to the plant and animal communities that depend on open habitat.  Without these scheduled burns, many native species, from butterflies to birds, would disappear. Spotted turtles would quickly become a distant memory.


Spotted turtle rare wildlife
Three spotted turtles by mid-afternoon was better than I could have hoped for, but I couldn't help but notice that another wet meadow species was conspicuously absent.  “There used to be massasaugas here?” I asked, knowing that the pygmy rattlesnake had been extirpated from all the lake counties thanks to human persecution.  “Yup,” Todd replied forlornly, “they were last recorded here in 1981."

Spotted turtles don’t suffer from the same violent disdain as snakes, but they face their own gauntlet of human mistreatment.  Plenty are killed on roads each year by oblivious drivers. Roadways and development have heavily fragmented the Oak Openings, splitting off habitats the turtles depend on.  Spotteds not killed crossing are commonly scooped up by star-struck drivers and taken home to waste away in captivity.  The pet trade is one of the biggest threats to the persistence of spotted turtle populations.  Black-market poaching focuses on adults (often gravid females) and can quickly collapse healthy turtle populations. 

Upwards of 500 breeding adult turtles is considered a viable population.  Many Ohio locality records are known from just one individual turtle, and groups of as many as 50 are still not considered sustainable long-term.  Being such a long-lived vertebrate, it can take decades before local extinctions are realized.  The Oak Openings is home to some of the larger remaining populations of spotted turtles in Ohio, but this rare wetland-loving woodland-dweller can still be found in isolated prairie remnants, bogs, and fens from northern to southwestern Ohio.  Their numbers are often so low that detecting them can be tricky, but given space, respect, and a little human help, they will hopefully persist long into the future.

Thanks for reading.
RBW  

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