Thursday, March 26, 2009

Seduced by a Siren

For the past several weeks, I’ve cheerfully placed my jacket and sweatshirt in the back of my closet several times, confident that the periodic warm spells had finally signified the last gasp of winter. After each of these gleeful episodes, I’ve had to grudgingly retrieve them the next morning after I opened my front door and was predictably greeted by the cold, crisp air. But now, surely, this is the real deal.

When I stick my head out of the window, I can no longer hear upland chorus frogs calling for mates. This winter-breeding amphibian, whose call sounds like a finger running down a plastic comb, is usually the first species to start singing each year, and the first to stop. Instead, last night I heard grey tree frogs and southern toads trilling in the pond near my home. It’s a good time of year.

Undergraduates at Auburn University sometimes conduct independent research projects for credit and for experience. Since my lab is known for studying interesting critters, there are often individuals working with us and looking for help with their projects, particularly when it gets warm and the amphibians and reptiles start to move around. Last week I received an e-mail from a student looking for help catching one of the most elusive animals in the south, the greater siren.

Sirens are a group of salamanders that don’t subscribe to the typical amphibian way of life, instead of laying their eggs in the water and waiting on land until the next breeding season, sirens simply never leave the water at all. They obtain oxygen through the large, feathery gills that emanate from their neck.

Over time, sirens have lost their hindlimbs and are left with only greatly reduced forelimbs, rendering them incapable of meaningful terrestrial movement. It’s no matter to these eel-like creatures as they patrol the watery depths, legs would only slow them down. We know very little about these secretive animals, they spend the majority of their lives in the muck lining the bottom of swamps, ponds, and similar bodies of water. We do know, however, that they are ruthless and effective predators. Sirens can reach lengths of three feet long and at that size there are few other animals in the water that aren’t potential prey.

The Auburn undergraduate was interested in shedding some light on the ecology of this little known organism. By capturing some and bringing them temporarily back to the lab, he hoped to make observations on how efficient they are at absorbing oxygen. The first step (and what I feel is the most fun part) was finding and catching the sirens.

On Friday afternoon we gathered on campus to collect our gear, into the van went numerous nets, crayfish traps, and a large seine. Crayfish traps, although designed for edible crawdads, are effective at capturing a large number of different animals. They have a simple design: plastic-coated wire mesh is molded into a rough pyramid shape; at the base, there are three funnels leading inside. Aquatic animals crawling around the bottom of the pond may find their way through the funnel and become trapped. The seine is even simpler, a ten foot rectangular net with weights on the bottom is stretched between two wooden poles; one person grabs each pole and drags the net (weighted side down) through the water. Animals get swept up in the net as it is brought through the water. After a sweep, the net is brought to land and the contents examined.

The van loaded, we headed down to Henry County, Alabama to search a pond that was the site of a siren study many years ago. On the drive down I envisioned wading through a vast expanse of marshy wilderness, parting reeds as I strolled through the water exploring the pristine swamp. Imagine my surprise as the van pulled to the side of the road alongside a farm pond surrounded by acres of grassland closely cropped by a multitude of cow mouths. This is it? I thought to myself as I surveyed the pond, similar to so many dotting the agricultural landscape of south Georgia and Alabama.

Carefully avoiding any cow patties, I gave the pond a preliminary examination. I noticed there were some tupelo trees along the shore and a few small patches of aquatic vegetation. I decided I would focus on these areas and any other form of structure I could find. I thought that in a relatively uniform pond such as this, any animals would be concentrated there.

In the fading light, we set out our crayfish traps. We’d check them when our evening was over. I grabbed a steel framed dip net and began to work the shoreline, thrusting the net into the water and working it along the bottom for several feet before hoisting it into the air. It didn’t take long before my arms began to tire from lifting the various leaves, sticks and assorted muck that I captured. After each sweep I eagerly and optimistically peered into the depths of my net, half expecting to see a squirming siren within my grasp.

I began having trouble with my headlamp, it seemed to blink out whenever I tried to see what I had captured, making for a frustrating exercise. It’s unfortunate that we weren’t there to catch aquatic beetles and other insect larvae, we could’ve made it an early night due to my great success. Any amphibians, however, effectively evaded me. I was considerably discouraged by the time I heard some excited yelling coming from the bank several hundred yards away.

Curious, I slowly made my way back to our starting point. By the time I had arrived, there was nobody in sight, however, there lay a large red cooler on the bank. The lid was weighted down by a bucket full of water. I couldn’t resist removing the bucket and peering inside the cooler. There, with gills billowing through a couple inches of water, lay a two foot long siren. Thick as a vacuum hose, the amphibian looked relaxed as I excitedly peered at him.

It turned out to be the only one captured that night, he had been nabbed during a sweep of the seine, likely as he hid within a leaf pack. Despite the traps, the seine, the nets, and six enthusiastic searchers, our success was limited. But the confirmed presence of just one siren indicates that there were probably dozens, if not hundreds more within the pond.

Sirens are rarely seen and hard to capture. We know little about the species, but you should consider how many of these huge, unique salamanders live within your neighborhood pond, marsh or lake. You may be surprised.

Tuesday, March 24, 2009

Reptile Van Winkle

I wrote this column last March, still relevant this time of year.

It’s finally starting to warm up around Auburn. On cue, red-winged blackbirds have begun to make their appearance known in area wetlands. You’ve probably heard them too, singing their distinctive, “Konk-a-ree!” About the size of a sparrow, males can be recognized by their black body and bright red shoulder patch. Small yet fiercely territorial, they’re often found perched on cattails, singing to attract mates and defend their little patch of swamp from other males.

Other animals are starting to appear and look around too. Lizards, snakes, and turtles are all beginning to emerge from the winter refuges to take advantage of the weather to warm their bodies. Most people know that these animals are reptiles and, like all reptiles, they are “cold-blooded”. This term isn’t used so much anymore in scientific circles because it implies that reptiles have no control over their body temperature. It is now known that some reptiles can keep their body temperature higher and more stable than we can, simply through their behavior. This is why you’ll see turtles lined up on a log over the water; they’re trying to raise their body temperature. You may have also seen alligators sitting on a waterbank with their mouth open, this is actually how these animals lower their body temperature. They’re letting heat escape through their mouths. Given how hot a Florida afternoon can be, I don’t blame them for trying.

But a reptile’s dependence on the weather outside brings up an interesting question, one that I hear a lot. If the temperature outside influences the internal temperature of reptiles, how do they last during the cold of winter? It’s a good question because it turns out that different animals have different adaptations for persisting in cold weather.

As you might expect, reptiles hibernate. But if you’re picturing a snake curling up in a cave like a bear might, you may be surprised. These animals don’t hibernate in the traditional sense, they are quite awake.

As cold weather approaches, lizards and snakes start seeking out shelter that will serve as their winter hibernacula (hibernation sites). Common areas include abandoned mammal burrows, gopher tortoise burrows, or the caverns surrounding burnt up tree stumps. In more northern climates, these animals will hibernate together and it’s not unusual to find timber rattlesnakes, rat snakes, and black racers all nestled together in rock outcrops. Down here in Alabama though, these animals tend to be loners.

In their refuges, snakes and lizards wait out the long, cold winter. Impressed? I get hungry just thinking about going just a few hours without food. Their secret is in their slow metabolism. Reptiles can go long periods of time without eating, particularly when it’s cold. As their body temperature decreases, so does their metabolism. Mammals like us need to use a lot of energy to maintain our body temperature, reptiles have no such obligation.

So they lay in their caverns, the cold around them making them sluggish. If these animals were truly hibernating, it would take them a long time to gradually retain their normal activity periods. But this isn’t what we see with snakes. You may have remembered that we received a warm spell over a month ago, during one of the warmer days I stepped outside and found a small red-bellied snake sunning itself on my sidewalk. This is a common, harmless snake in the Auburn area and all are less than a foot long. During warm weather, snakes and lizards may often come to the surface and enjoy the sun’s rays. The small snake that I saw likely crawled back to his shelter that night, before temperatures got too cold again.

Turtles have particularly fascinating strategies for escaping the cold. Most of the aquatic turtles you see will burrow in the mud at the bottom of their pond and swamp and wait for warmer weather there. Now, we’ve already talked about why reptiles don’t need to eat during the winter, but now there’s another problem. How do the turtles breathe?

Since their body is running at such a slow speed, turtles don’t need much oxygen. But holding their breath for months would be a feat not even they could accomplish. Although it may be hard to believe, but turtles are able to absorb oxygen from, for lack of a better term, their butt (technically referred to as a cloaca in reptiles). The chemical processes that turtles undergo during cold temperature are quite interesting and complex.

Swamp Moccasins

This column was originally written in June 2008.








I yelled out, “Here’s one. Snake!”

“Alright, I’m on my way”

“Do you want me to take it?”

“Do it!”




“Another snake!” I yelled out again.



In Over My Head

This column was originally written in July 2008.




“Okay, I’ll bring it…just in case.”

This proved to be a wise decision.












Monday, March 23, 2009

From Dusk 'till Fawn

This column was originally written in August 2008.











A successful capture from a previous effort


Sunday, March 22, 2009

Shell Shocked

This column was originally written in September 2008.

Our mission: upon locating North America’s largest species of turtle, pry it out from under the submerged logs and limestone caves on the bottom of frigid Spring Creek, taking great care to avoid its prominent jaws as we brought it to the surface. Easier said than done.

The alligator snapping turtle is found primarily in the southeastern United States in rivers and creeks that drain into the Gulf of Mexico. They can reach over 200 lbs, although they’re seldom that big. A beast of a turtle, they prowl creek bottoms searching for dead fish to eat. A turtle this size has few natural predators, patrolling its riverine hideaways with impunity. And yet, we almost lost it forever.

Close your eyes and picture a can of turtle soup. This is the closest that many people have ever gotten to an alligator snapping turtle. After decades of unregulated harvesting, populations of this species declined precipitously. Protections were recently put in place and these turtles have slowly started to rebound, but it’s a precarious recovery and populations are still vulnerable.

This species is a secretive and rarely studied animal; but John Jensen of the Georgia Department of Natural Resources is researching a population in southwest Georgia. By trapping for turtles over many years, he can estimate the size of the population based on how many individuals he recaptures. These efforts also provide baseline data necessary to monitor the population and determine if it’s stable.

Once a year, John supplements his normal trapping routine by inviting biology graduate students and his colleagues for a snorkeling trip in an attempt to root up some turtles that have eluded capture. We met early at the public boat ramp before the crowds arrived to cool off in the water. It was a large group this year, about 20 people. Some had brought their SCUBA gear; they knew what they were in for. I looked forlornly at my snorkel and wondered how long I could hold my breath while wrestling with a giant turtle.

After a brief introduction to our mission (the only reason we were able to handle these protected animals is because we were helping a state biologist), our fleet of kayaks and canoes slipped into the water and headed downstream to the study site. I was content to float along but others quickly donned their gear and submerged. I saw snorkels crisscrossing the creek and bubbles burst through the water’s surface as divers explored the depths.

It wasn’t long before I started seeing hands full of turtles thrust skywards as Barbour’s map turtles, yellow-bellied sliders, and river cooters were found. Although these weren’t the species that we were targeting, they still provided valuable information. One student even collected leeches for a parasite study.

As the morning waned, our flotilla dispersed widely. But suddenly I heard some news that had spread quickly among the trail of boats. One of the SCUBA divers had found a snapping turtle.

I muscled my kayak around and doubled back, paddling against the current until I reached a crowd of boats floating around a mass of giant logs and trees lying flush against the steep banks of Spring Creek. Apparently there was not one, but two giant alligator snapping turtles wedged in a submerged cave. A strategy had to be crafted, the turtles were too far back and in too tight to simply be dragged out. The divers submerged repeatedly with no success. Finally, from the depths came a massive turtle, firmly within the grasp of one of the intrepid biologists.

The beast’s massive jaws gaped menacingly, daring us to let a careless hand stray too closely. Water poured off its serrated shell, sufficient protection from any predator besides us. The turtle was carefully maneuvered to shore, where it was measured and marked for future identification. After a few photos, we allowed the 40 lb animal to slip back into the creek. In the excitement, the other turtle had given us the slip as well, and we didn’t catch another turtle on this trip.

When we reached the designated end of our survey, we were free to enjoy the scenery. At our start point, Spring Creek is small and almost completely shaded by overhanging trees. But as we flow south the water flow becomes increasingly influenced by Lake Seminole. The creek opens up widely and marshy areas are more common. Good habitat for alligators, not so great for snorkeling.

Despite our day-long effort, the miles we covered, and all the seasoned turtle biologists on the trip, we caught sight of only two alligator snappers. We have no way of knowing how many we missed, surely there are more prowling the depths. But our efforts indicate how the loss of only a few individuals may resonate within a creek.

Saturday, March 21, 2009

In the Heat of the Night

This column was originally written in January 2009.

Last month, I traveled to Atlanta to visit a “Dialogue in the Dark” exhibit, wherein participants are plunged into total darkness and led through several scenarios and arenas by a blind guide. The formal goal of this exhibition is to promote awareness of blind and similarly disabled people by enabling participants to experience life as they do. I suspect that many ticket holders aren’t entirely selfless and also visit for the thrill and the novelty. I’d like to say I was in the former camp, but there was admittedly something about stumbling around in the dark that sounded exciting.

As I approached the entry point of the tour, I was provided with a cane and lead to a seat in a weakly lit room. I was pleased to see that there were several young, giggling children present. If I were to get separated from my group, I schemed that I could follow the sound of their shrieks back to safety. The lights slowly dimmed as a resonating pre-recorded voice reassuringly introduced the exhibition. It gently informed us that darkness is often associated with danger, but this is seldom accurate. Just seldom? A wave of anxiety passed over me as I was enveloped by the inky blackness of pure, unadulterated darkness.

Out of nowhere (but then again, so everything seemed in the dark), we heard the voice of our tour guide instructing us to slowly stand and make our way towards him. And so began our dialogue. I’ll save you from the details; I recommend you experience the tour yourself, but as I stumbled through the various rooms and scenarios, leaping away from the inquisitive hands of my sightless companions (there was more awkward groping than at your typical high school prom), I envied snakes.

We humans like to think that we are the pinnacle of biology, perfectly suited for any situation. But, we tend to stick to circumstances that we’re comfortable with, restricting most of our activity to the daylight hours. There are actually entire senses that we completely lack, including the ability to detect heat. In the woods, in the dark, it is this sense that allows pit vipers to find their prey.

There are five species of pit vipers in our region, including cottonmouths, copperheads, and timber, diamondback and pigmy rattlesnakes. Ever wonder why they’re called pit vipers? Each of these snakes has a small opening in front of each eye that leads to an organ that can detect infrared rays given off by heat.

Light is made up of different wavelengths; the length of each wave determines what color we see. But there are waves with lengths well beyond what humans can detect. Infrared rays are made up of wavelengths in this category.

Infrared rays hit a membrane within the snake’s pit organ; where the rays hit signify to a snake the relative location of a warm prey item. Warm objects stand out against a colder background (watch the movie “Predator” for a stylized representation) and since a snake has a pit on each side of its face, it’s able to pinpoint the location of unlucky mice or rats that scurry by.

It’s a surprisingly accurate system; you just try to grab a mouse with your eyes closed. The pit organs are so sensitive, vipers may detect when something is 0.4 degrees Fahrenheit (or less) different than its surroundings.

Who needs eyes when you can see heat? A pit viper would not have been as awkward in the dark as I was, tripping over my cane, trying to get my bearings, all while attempting to figure out what I was touching, which at least once included someone’s backside. As to how warm it was, I couldn’t accurately say.

Thermal camera photograph of yours truly courtesy of Richard Bryant

Friday, March 20, 2009

Diamonds on the Move

This column was originally written in fall of 2008.













Thursday, March 19, 2009

Gone on a Bender














The author and a hellbender survey crew on a
previous effort in northeast Georgia in 2005

The column originally ran in November 2008

Hellbender photos courtesy of Jeff Humphries

Wednesday, March 18, 2009

Hopper Poppers


Thursday, March 12, 2009

Long Walks on the Beach...

Although Mother Nature has recently offered some tantalizing glimpses of the impending spring weather, it’s been bitterly cold lately. So cold that I would not have been motivated to take a stroll through the woods even if there had been any critters crawling around. Just as all the snakes have been coiled in their dens and underground caverns, I have been holed up inside, on my couch. It’s a time for quiet reflection, for remembering warmer times and places.

About eight years ago I visited Costa Rica in a quest to find exotic reptiles. A highlight of the trip, and of my life, was the night we visited Tortuguero, a sea turtle nesting beach on the Caribbean coast.

At Tortuguero is found the Caribbean Conservation Corporation , an organization created in the 1950s to protect and better understand the plight of the critically endangered sea turtles that nest in the area. At night, we met with researchers to guide us as they searched for turtles along the moonlit shore. As we marched along the shoreline, my eyes kept drifting to the dark and menacing jungle that began immediately where the sand ended. The forest harbored jaguars, lots of them, and they were patrolling the same stretch of beach. Sea turtles are an important food source for the big cats; they killed and ate dozens of them that nesting season.

We had only the moonlight to guide us. Flashlights disturb the turtles and were forbidden. I squinted in the dark to better make out any turtle trails in the sand before me; these are the telltale signs of a female nesting nearby.

We walked for hours as the waves lapped against the beach and my oversized rubber boots rubbed my calves raw, yet we saw no turtles. The night wore on as we diligently marched and we had covered about four miles by the time we had returned. Disappointed and exhausted, we slumped into anything that would hold us and rested our eyes.

No sooner had our eyelids begun to slowly lower did garbled voices spring from the researchers’ radios. What was going on? I strained to make out the conversation. Another group had located a turtle down the beach. Did we want to go, the researchers asked? I have to admit that I hesitated briefly, I was so comfortable after our long arduous hike, but I quickly got my second wind. As we marched towards the other group, we caught word that the nesting turtle was a leatherback and our excitement soared.

Leatherback sea turtles are one of the largest reptiles in the world. The biggest on record measured nearly ten feet long and weighed over 2,000 pounds, that’s a huge turtle. But their size isn’t all that makes them special. They’ve been documented diving to depths in excess of 1,000 yards (10 football fields), they eat poisonous jellyfish, and their warm metabolism allows them to inhabit the cold water of the northern oceans. They’re truly a unique animal. But they’re declining worldwide.

Leatherbacks are critically endangered. Major threats include accidental capture by fishermen, over-harvest for food, pollution, and destruction of nesting sites. Turtles also eat plastic bags that have made their way into the ocean; the turtles are unable to distinguish between the bags and their jellyfish prey. The mistake is often fatal.

Turtle populations aren’t accustomed to experiencing high levels of adult mortality. Of the many young that are produced each year, only a few escape the hungry eyes of seagulls and large fish. This makes breeding, adult turtles especially valuable, and now, after a long, arduous, late-night hike, one was suddenly before me.

The researchers were working with flashlights covered by a red film; this keeps the light from disturbing the beasts while nesting. A weak beam of light briefly illuminated the turtle’s basketball sized-head; I glimpsed one of her eyes and was in awe. Many years ago, this turtle likely emerged from a nest on this very same beach. For decades she had defied the odds, reached a huge size, and returned to deposit eggs of her own. And I was here to see this feat of nature.

When the biologists gave us the okay, I reverentially ran my fingers along the length of her five-foot leathery shell and gently grasped one of her giant flippers. I don’t know how long we watched her; I lost all sense of time. After the ancient turtle had dropped perhaps 80 eggs, she used her back flippers to fill the nest with sand.

Nesting complete, the turtle made her way back to the sea. Her flippers were made for swimming the open ocean; her awkward motions seemed out of place as she flapped and floundered her way to the water. It was a most inglorious ending to an otherwise graceful event.

As we made our long way back along the beach, I was on a high. It hardly bothered me when someone pointed out some fresh jaguar tracks alongside the footprints we had left earlier. The tracks hadn’t been there when we crossed the first time.

Photo of leatherback sea turtle courtesy of the Caribbean Conservation Corporation /

Wednesday, March 11, 2009

Hanging By A Thread

On a brisk night last fall, I found myself hanging off a moss-laden cliff, clinging to a rope for dear life and trying not to look down. As the light from my headlamp careened around the wall of dirt in front of me, I cast furtive glances upwards, silently willing the rope to hold me and the knot to stay wound around the tree above. A tree which appeared sturdy enough earlier but now seemed to be giving a little too much. I took a deep breath, closed my eyes, and tried to focus on the task at hand; I was here to capture one of the rarest animals in the world, the federally threatened Red Hills Salamander.

This salamander, Alabama’s state amphibian, is found solely in south Alabama, and in very specific habitats. To my great misfortune, these specific habitats are steep slopes and ravines. I vainly tried to gain a foothold among the loose dirt clods on the cliff, gingerly moving so that I didn’t disturb the ground or accidently squish a salamander as miniature avalanches of dirt and small rocks cascaded down around me.

Red Hills salamanders live nearly their entire lives in small burrows on these cliffs, often only their head is visible as they peek out from their subterranean caverns. They’re thought to rarely leave them. Unlike many other salamanders, hatchlings do not develop in water, females lay eggs within their burrows and that’s where the young are born. Interestingly, the hatchlings possess gills for their first few days of life, perhaps a reminder of their more traditional ancestors.

Red Hills salamanders have a few things going against them. Due to their extremely small range (five counties in south Alabama) and their specific habitat requirements (steep slopes), there just aren’t a lot of places for them to live. Combine that with logging practices that degrade their homes and it’s easy to see why the salamander is in trouble.

The inevitable march of human “progress” is stepping on this rare species. I was helping a colleague, contracted by the state, capture all the salamanders on this cliff before a road construction project destroyed the entire area. It’s a common misconception that endangered species often halt construction and development projects, what typically happens instead is developers first make some concession to limit their environmental impact and then proceed as usual. When the next project comes along, they make another concession, and so forth. It’s not surprising why it’s hard for endangered species to recover, although there are some success stories.

As I swung back and forth looking for salamander burrows, my waist harness creeping up uncomfortably, I figured that there must not have been a large concession. Our goal was to catch salamanders here so they could eventually be relocated elsewhere. It was a risky proposition as there was no way of knowing if the relocated salamanders would take to their new home, but it was better than the alternative, (i.e. leaving them to get paved over).

About an hour after arriving, my headlamp suddenly illuminated what I thought was an eyeball. When only their head is visible in their burrow, it’s hard to imagine how big Red Hills salamanders can grow, nearly a foot long. These slender animals are a nightmare to any unfortunate cricket that might stroll by their burrows. In a flash, the salamander will emerge, mouth agape, to grasp any insect that it can cram down its gullet. I trained my light on the little cavern and slowly maneuvered closer for a better look. A salamander face looked back at me. I reached into my pocket for a bag of crickets, moving very slowly to avoid scaring the skittish creature back into the depths.

It takes some finesse to catch these animals. There’s really only one reliable method: fishing for them. Still moving as slowly and deliberately as possible, I impaled a hapless cricket onto a barbless hook and gently placed the insect in front of the burrow. I should interject here that we took every precaution to minimize stress on the salamanders; we likely wouldn’t have used this method if it weren’t so important to catch and relocate the animals. This was a specific conservation effort sanctioned by state and federal authorities.

When the salamander detected the cricket, it was instantly interested and on the prowl. With focused intensity, the amphibian zoned in. Mirroring the salamander’s concentration, I willed it to take the bug bait. Seemingly in slow motion, the salamander began to open his mouth. This was it, I readied myself. It continued to open its mouth so wide that it could no longer see the cricket, understandably reducing its aim. As I watched the salamander awkwardly miss the cricket several times, I wondered how they ever catch enough food to survive. Eventually however, the salamander did figure out the right angle, and I quickly secured the animal. As I gently removed it from the burrow, I admired the strange creature in front of me.

Red Hills salamanders not as bulky as other amphibians you might see, they’re long and slender with greatly reduced limbs. Overall, it reminded me of a worm. An unflattering description, but they’re surprisingly charismatic, perhaps because of their large, inquisitive eyes. I gently removed the hook and placed the salamander within a small tube, we hoped it would remind it of its burrow.

I waited until the salamander was safely secured in its tube before I yelled to the others that I had caught one, the first of the night. They responded with their praise. I was starting to get the hang of this whole night mountain climbing thing after all; I could hardly notice the creaking rope, the dark abyss below me, or the intimate relationship I had developed with my harness. I managed to catch another salamander, two of several captured that night.

I hoped the salamanders would be content in their new home. They’d be safe for now, at least until they start talking about the next road construction project.


Over a year later, the road construction has yet to occur and the salamanders have been brought back to their original burrows. Due to the large number of salamanders documented in the effort described above, the United States Fish and Wildlife Service required a revision to the original blueprints. The updated plans now require the roadway to miss the majority of the burrows; however, the highway will separate the remaining salamanders.