It stank – the mud into which I sank to my knees emitted a lovely odor akin to a fridge full of rotten eggs.  The sun had barely risen early that June morning, and the heat and humidity in that marsh near Sabine Pass in Jefferson County, Texas were already oppressive.  The deerflies too, were wide awake and busily seeking out any patch of skin left exposed to the elements.  Sure, it sounds miserable, but these irritants and inconveniences are just one small part of the story.

I stopped moving a moment to catch my breath.  The marsh is as flat as a pancake, but traversing it is grueling work.  Stepping up and over mud and densely tangled grasses and sedges takes its toll.  The break afforded me the opportunity to really take in my surroundings.  Seaside dragonlets, no longer startled by my movements, landed all around me, coming to rest atop swaying blades of grass swaying in the breeze.  My ears honed in to the distance buzzy songs of Seaside Sparrows, Red-winged Blackbirds, and Boat-tailed Grackles.  And then I was haunted by the ghost of the marsh.  The loud, unsettling cacophony of “keks” and “grunts” from a pair of Clapper Rails rang out within just a few feet of me.  But try as I might, I was unable to catch even a fleeting glimpse of these highly secretive marsh dwellers.

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I understand that the saltmarsh isn’t for everyone.  It is a harsh, unforgiving, seemingly inhospitable landscape.  But for those who brave her less appealing attributes will find a wonderful world filled with beauty, biodiversity, and a host of plant and animal species that are found nowhere else on earth.  In Texas, these special places are restricted to a narrow band of tidally influenced wetlands along the coast.  They are declining and under threat from sea level rise, coastal development, and a suite of other pressures.  This is their story.

I have long had an affinity for the saltmarsh.  It is a love affair that began some 15 years ago, when my mom developed a passion for birdwatching and we began visiting sites like Anahuac National Wildlife Refuge on the upper Texas coast.  After finishing my undergrad I was lucky enough to land a seasonal job conducting bird surveys at Anahuac.  My transects included several areas of expansive saltmarsh deep in the heart of the refuge, in an area rarely accessed by visitors.  One particularly fond memory that sticks out from my time on the refuge is a long trek deep into a Spartina patens high marsh one evening just before dusk.  The refuge biologist invited me along on the annual Whimbrel count, when we tallied thousands of the curve-billed shorebirds as they flew over the marsh from foraging sites in tidal pools and mudflats to some unknown roosting site.  Trudging through the marsh we accidentally flushed a Mottled Duck from her nest, and discussed saltmarsh snakes, diamondback terrapins, and other species that find refuge here among the fetid mud and salty air.

After I finished my Master’s, I had another opportunity to spend a few months in the marsh.  This time in the diverse marshes that filtered the Chesapeake Bay in Maryland and Virginia.  While there I helped conduct extensive surveys for secretive marsh birds like Seaside Sparrows, Saltmarsh Sparrows, Clapper Rails, and the mythical Black Rail.  The work involved setting out before 4 A.M. and trudging miles through marsh that was like Swiss cheese, with hidden holes that swallow one whole.  It was absolutely miserable, and I look back on my time there with great fondness.

The coastal marshes of the Texas and the Chesapeake Bay are at the same time similar and different.  They share many of the characteristic plant species like Spartina alterniflora, Spartina patens, Distichlis spicata, Juncus roemerianus, and Iva frutescens.  Even many of the bird species were the same.  Seaside Sparrows (Ammospiza maritima) and Clapper Rails (Rallus crepitans) are present in both, though the subspecies (if such a thing exists) are different.  Other species like the Saltmarsh Sparrow are absent in Texas, and the Diamondback Terrapin, while present in both areas, is much more numerous and readily observed along the Chesapeake Bay on the Delmarva Peninsula.  There were days when I would see hundreds basking and swimming through various bays an inlets, their heads barely peaking above the water’s surface.  In Texas, terrapins remain generally uncommon and highly localized.

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Back in the marsh in Jefferson County, I heard a Seaside Sparrow singing close.  These remarkable birds are found only in these tidally influenced marshes directly adjacent to the coast.  They range from the southern tip of Texas to Cape Cod and southern New England.  Some eight subspecies are recognized, with one, the Dusky Seaside Sparrow (Ammospiza maritima nigrescens) having become extinct and a number of others that are of conservation concern.  The birds of the upper Texas coast belong to the subspecies (A. m. fisheri), which differs from other subspecies by possessing a combination of buffy coloration on the breast and dark streaking on the back.

Seaside Sparrows are year round residents in this marsh.  They’re easiest to see in the spring and early summer, when they occasionally poke their heads above the grass in to sing a song of mate acquisition and territory defense.  Mated pairs build their nest in tidal marsh with dense grasses just a few inches above the high tide line, a strategy that helps protect them from predators.  The parents feed the developing chicks a variety of insects and other inveterate prey.

I watched one morning as a pair foraged in a barren sand flat exposed during low tide.  They gleaned flies, grasshoppers, and caterpillars from halophytic (salt-loving) saltgrass (Distichlis spicata) and saltwort (Salicornia bigelovii).  I soon realized that this was a bird as comfortable on the ground as in the air, as I watched them mouse about the sand in a manner more mammalian than avian.  Once they had collected a mouthful of juicy insects, they would fly back into the marsh to feed their growing progeny.  I contemplated trying to find the nest, but feared that by plodding through the dense grass I might destroy it.  I returned to the same spot the following morning, hoping I might spot my friends again, but found the area completely flooded by the incoming tide.

When the June sun gets high in the sky, the Seaside Sparrows and other marsh denizens tend to lay low.  I could hardly blame them, and Caro and I took a page from their book and went to lounge on the beach in Sea Rim State Park.  We had both been feeling the need to get away, and planned a way to do so while remaining socially distant and minimizing our risk of exposure to the virus responsible for the COVID-19 pandemic of 2019-2020.  At Sea Rim we had an entire stretch of beach entirely to ourselves.  As we relaxed in the rolling surf we watched as Least Terns, Royal Terns, and Brown Pelicans fished just offshore.

As the sun drops lower to the horizon, the marsh begins to come to life again.  We returned to the grass jungle, and I found a stretch of marsh that seemed to have a different Seaside Sparrow singing every 100 feet or so.  It was the densest population I had ever observed.  It made me smile, knowing that this fascinating songbird has found a refuge here

The sparrows literally emerged from the grass as I sat still, watching seaside dragonlets come in to rest at the apices of the marsh grasses.  Seaside dragonlets are tiny dragonflies that are endemic to the saltmarshes of the eastern U.S.  They are one of only a handful of dragonfly species whose aquatic nymphs can survive in saltwater.  I wondered of a sparrow may be quick enough to capture one of these dragonlets, but they seemed preoccupied with much easier prey, like the tiny snails hunkered low in the grass.

As most marsh vegetation is herbaceous and not particularly sturdy, the Seaside Sparrow needs to be creative in how they move about.  I witnessed incredible acrobatic feats as the sparrows hopped among the grass, from blade to blade, and performed the splits numerous times as they sought to stabilize themselves in the breeze.  To me, it seemed such a hard place to live.  But to the Seaside Sparrow it was home, and life was good.

The saltmarsh is generally divided into two sections – low marsh and high marsh.  The low marsh is that area that is flooded daily by the tides.  It is generally only completely exposed during the lowest of tides, and occurs directly adjacent to bays, inlets, and the saline and brackish creeks feed them.  Low marsh is dominated by taller halophytic vegetation, most notably smooth cordgrass (Spartina alterniflora).  As the elevation gradually rises moving inland, the community transitions to high marsh.  High marsh is dominated by species like seameadow cordgrass (Spartina patens) and is inundated infrequently, usually only by the highest of tides.

Some species show a marked preference for one type of marsh over the other.  Clapper Rails (Rallus crepitans), however, may be encountered in both communities, retreating from the incoming tide, and chasing the receding tide in search of crabs and other prey items.  People are often surprised when I tell them that the Clapper Rail is one of my all time favorite birds.  To most they seem drab, awkward, and uninteresting.  Admittedly, part of my fascination for this species is nostalgic, having spent time studying them in the marsh.  But they are also fascinating, enigmatic creatures.  They are at the same time secretive, but not shy, often willing to approach very closely under the cover of marsh grass.  I have also watched them hunt for crabs within mere feet of where I stood watching.

The marsh explorer will often here, but seldom see the Clapper Rail.  They are highly vocal, communicating internally within family groups, and externally to potential rivals through a series of “keks”, “grunts”, and even “hoots”.  Nicknamed the “ghost of the marsh”, these rails seem to haunt the deep grass with their eerie cacophony, and will often call in the blackness of night.  Spend enough time in the saltmarsh, however, and you will eventually catch a glimpse of one of these cryptic denizens as they dart across a tidal pool or scurry into a mudflat in hot pursuit of a fiddler crab.

There is an interesting relationship between Clapper Rails and King Rails, a very similar closely related species.  The differences between the two are subtle, with King Rails generally having a richer chestnut color on the back and breast and more prominent barring on the flanks, and Clapper Rails having a gray wash to the cheeks.  Individuals seen in the saltmarsh tend to be pure Clapper Rails, while individuals just a few miles inland in the freshwater Marsh tend to be pure King Rails.  There is a broad contact zone, however, in areas where an influx of freshwater dilutes the highly saline sea water forming the brackish marsh.  The rails here, often referred to as “Cling Rails”, are purported to be hybrids, and tend to exhibit characteristics intermediate between the species.

Like Seaside Sparrows, Clapper Rails build their nests just above the high tide line.  They are seasonally monogamous, and males and females work together to construct the nest, incubate the eggs, and raise the young.  The young are precocial, meaning they are capable of leaving the nest very quickly after hatching.  Family groups will stay together for some time as the chicks grow and learn to fend for themselves.  I most often see three or four chicks to a group, but in good years with abundant resources they may be capable of raising more.  In leaner years, however, the parents may kill or alienate a part of their brood in order to better provide for the remainder.  I will never forget witnessing this one year, when birding with my parents and a friend we saw a rail pair viciously pecking one of their chicks.  In spite of this, the poor chick kept trying to follow them until finally it was too injured or disheartened to do so, and it was left on its own to die.  This seems so cruel and harsh to us, but in reality it is behavioral adaptation that has evolved in order to ensure that the entire clutch doesn’t die from starvation in a scenario where the parent would be unable to care for them all.

As it was for the Seaside Sparrow, the marsh in Jefferson County was literally packed with Clapper Rails, in a density higher than I can recall encountering anywhere prior.  Many don’t realize that Clapper Rails, and other rail species, are actually game birds, and they are legal to hunt.  It was apparently once a popular pursuit in parts of the East Coast, however today interest seems to have waned.  I imagine it is an endeavor seldom pursued due to the difficulty in seeing a rail, let alone getting it to flush to a point that a shot could be made.  Their preference is to run from danger, under deep cover of grass, rather than fly.

Watching a family of Clapper Rails at close range, I came to a realization.  From a human’s vantage point, the marsh seems some exposed environment.  There is little relief from the blazing sun.  However when we see it from the point of view of the animals that live there, it is actually a mysterious world full of shadows that may as well be a forest to them.  Perhaps this is what prompted naturalist William S. Burt to title his book on rails “Shadowbirds”.

There is much more to the saltmarsh than our feathered friends.  I hoped to capture an image of a diamondback terrapin or saltmarsh snake, however it was not meant to be during my time around Sabine Pass.  The wildflowers, however, proved to be much more obliging subjects.  Mosquito infested saline marshes may not be the first place one would go looking for showy blooms, however there are a number of species endemic to these communities, with others showing a definite preference.

Perhaps the most prominent is the sea oxeye daisy (Borrichia frutescens).  This member of the sunflower family (Asteracea) flowers throughout most of the spring and summer.  It ranges along the Atlantic and Gulf Coasts, and is capable of surviving regular inundation by saltwater.  Like many salt-adapted species it has thick, succulent like leaves.

Saltmarsh false foxglove (Agalinis maritima) was also in bloom.  Another salt-loving plants, their distribution is limited to coastal marshes from northeastern Canada into Mexico.  The plants seem dainty, however they are capable of withstanding the nearly constant sea breeze.  The blooms open in the morning and typically close by the early afternoon.

Some species, like the seaside gentian (Eustoma exaltatum) are not confined to saltmarsh habitats, but are fully capable of surviving the harsh conditions of the marsh, including highly saline soil, regular influx of tidal waters and extreme temperatures.  The taxonomy of Eustoma is confusing and controversial.  Some consider the species that occurs along the coast to be the same as those occurring further inland in blacklands and other prairie remnants.  Those prairie plants display a markedly different morphology and habitat preference.  The coastal specimens are quite similar, however, to plants in areas with similarly harsh edaphic conditions in parts of West Texas.

The biologist in me likes to keep up with constantly changing taxonomy of plant and animal species, in part so I can remain relevant in my field.  To the naturalist in me, however, prefers not to get bogged down in the semantics of these taxonomical revisions, and instead focus on the beauty, function, and relevance of the organism in its landscape.

I have a certain affinity to species endemic to a given community.  There are, however, many other species that are capable of surviving in a variety of habitats.  This highlights the concept of specialists, like the Seaside Sparrow and Clapper Rail, to generalists, like the Scissor-tailed Flycatcher (Tyrannus fortificatus).  These handsome flycatchers inhabit a variety of open habitats including marshes, prairie remnants, savannas, fallow fields, forest edges, and areas that were recently cleared or otherwise disturbed.  Generally they choose areas that have some scattered small trees or shrubs nearby, which they select for nest placement.

Scissor-tailed Flycatchers leave an impression on those who are fortunate enough to observe them.  Those impressive tail feathers may serve an important function in mate acquisition.  Research on birds with similarly long tails indicates that females are attracted to the males with the longest, gaudiest tails.  As one can imagine, that lengthy caudal plumage can be an encumbrance, and can make a bird more susceptible to predation.  Therefore, males who are able to survive despite this impediment are communicating to females that they are superior quality, and they possess the best genetic material to pass on to the next generation.

Different species exhibit a gradient of habitat tolerance.  Some, like the Red-winged Blackbird (Agelaius phoeniceus) are specialists in a broader sense, showing a preference for wetlands with ample emergent vegetation, but generalists in the sense that they are capable of inhabiting a variety of different wetland types dominated by a variety of different plant species, and are dispersed across a wide range of landscapes.  Perhaps a good term for species that exhibit this type of habitat preference would be “specialist generalist”.

The song of the Red-winged Blackbird is perhaps one of the most familiar sounds of the marsh.  It is at the same time obnoxious and beautiful.  While singing, the males puff out their chests, bow up their wings, and flash those brilliant red and yellow epaulets.

The Least Bittern (Ixobrychus exilis), too, is a creature of the marsh.  Though they range as far north as the Great Lakes, and are most commonly associated with fresh water marshes, along the coast they can be found in brackish marshes and even low saltmarsh.  The males are identifiable by their forest green crowns and backs.  Seen at close range, they seem so colorful, but when perched among the grasses of the marsh, they become essentially invisible.  

This narrative has barely scratched the surface of the biodiversity of the saltmarsh.  It is my hope that my words and images help the reader connect with these special places.  High quality saltmarshes are being lost at an alarming rate.  They are under serious threat from pressures like coastal development and sea level rise.  We must act soon if we are to save these special places, and the diverse plants and animals that call them home.

For my parting shot, I chose this image below of a beautiful Seaside Sparrow among the saltgrass.  Though their overall color scheme is one of browns and greys, there are subtle hints of colors, from the bright yellow of the lore and marginal coverts to the orange mustache.  These good looks combined with their fascinating life history make them one of our great state’s most unique, interesting songbirds.

To the marsh, to the rails and the sparrows, and to the fiddler crabs and the terrapins, I say “farewell, for now.”  But I know it won’t be long before the saltmarsh calls to me again, beckoning me to lose myself among the reeds, muck, and mire.

 

 

Target Species: Alligator Snapping Turtle (Macrochelys temminckii)

I’m a little embarrassed that it has taken me all the way into May to check off the first species of 2020 from my list of biodiversity goals, but it was a good one – an ancient leviathan dwelling in the depths of a murky stream meandering through a mature hardwood forest – the old loggerhead – the alligator snapping Turtle (Macrochelys temminckii)

This story begins in January, with a meeting at my Alma Mater – Stephen F. Austin State University (SFA) in Nacogdoches, Texas.  I met with Dr. Chris Schalk, a herpetologist and ecologist with the Arthur Temple School of Forestry, the department where I obtained my undergrad.  We discussed ways that we may collaborate on topics like road ecology and reducing impacts to wildlife from transportation projects.  I immediately liked Chris, and found him a like-minded individual in many respects.

In the following months we touched base from time to time, and in one of our conversations he mentioned the research being carried out by one of his graduate students, David Rosenbaum.  Chris recounted the start of their field season, during which they captured numerous large alligator snapping turtles.  And much to my delight, he invited me to join them on a future outing.

It may not be surprising to the followers of my blog, but this sort of thing is right up my alley.  One of my most memorable jobs was when I worked a summer as a field tech on an American alligator research project.  Capturing these ancient reptiles was equal parts thrilling, interesting, and rewarding.  The idea to relive that in some small part was an opportunity too good to pass up.

So in late May I met up with David, and field techs Laura and John Michael.  Also along for the day was my good friend and frequent adventure companion, James Childress.  After some brief (socially distant) introductions, we were on our way to the first study site, a tributary to the Angelina River deep in a remote hardwood bottom.

Blooming American elderberry lined the banks here, and  the boughs of ancient River Birches and American elms reached out over the water.  From high in the canopy the buzzy trill of a Northern Parula rang out.  A suite of other songbirds also made their presence known, including a Prothonotary Warbler, Hooded Warbler, Swainson’s Warbler, Yellow-throated Warbler, Red-eyed Vireo, Summer Tanager, and Acadian Flycatcher.  In the distance we could hear the cackle of a Pileated Woodpecker and the croak of a Yellow-billed Cuckoo.  It was immediately clear that this site was rich in biodiversity on land and air.  We would soon realized it was equally diverse beneath the water’s surface.

For the first year of their study, David and Chris are replicating a survey performed twenty years ago.  When I added the alligator snapping turtle to my list of biodiversity targets, I knew that I would have to think outside the box if I had any hope of photographing one.  This is not a species that one can expect to find by conventional means.  They spend virtually their entire lives at the bottom of streams, rivers, lakes, and deep swamps.  They can stay submerged for nearly an hour, and the only time they can be expected to seen on land are when the females leave the water to lay their eggs, and the rare occasion when an individual disperses to a new water body.  In short, I knew if I wanted to see one, it would have to be trapped.

Fortunately, that was exactly what David, Laura, and John Michael were doing.  They use special partially submerged traps that allow for the turtles to be captured alive and unharmed, and check the traps daily once they’ve been deployed.  I was joining them for the third day of trapping effort at this particular site, which had several traps spaced out along this meandering forest stream.  The first day trapping here they caught six individuals, however the previous day they had caught none, so no one really knew what to expect.

The first trap we checked was empty, save a decent diversity of riverine fishes.  The second did have a turtle.  It was an interesting species, but not the one we were looking for.  Razorback musk turtles occupy similar habitats to alligator snapping turtles, and have been the subject of previous studies by SFA.  I didn’t photograph our first turtle of the day, but was certainly happy to see it.

Soon after the three researchers sank into the chest deep water at the third site, I heard David call out, “We’ve got something big in this one!”  It was a special thing, seeing him reach into the depths and pull out this massive, prehistoric-looking beast.  In that moment I thought of the fascinating ecology of these streams.  Beneath the water exists a diverse world that is unknown and unseen by most.

They pulled the massive turtle to the shore so that they may collect a variety of data, including morphological measurements, images, and blood and tissue samples.  It was determined to be an old female weighing in at nearly forty pounds.  We knew she was old, based on her smooth carapace.  When young, they have three raised ridges with scutes that form triangular peaks.  After years and years of wandering under woody debris lodged in the stream bottom, the shell gradually wears down until, in very old individuals it becomes essentially smooth.

We knew she was old, but we had no idea how old.  Large turtles can live a very long time.  When collecting those previously mentioned data, David and his team noted that the turtle had a distinctive notch in her shell.  It turned out that she had been captured during the original survey, 20 years ago.  We aren’t sure how large she was at that time, but that information should be available, and I’m very interested to find out!

David’s study will be looking at a variety of aspects related to the ecology of alligator snapping turtles in eastern Texas.  One aspect of his research is very similar to my own master’s thesis – using presence/absence data to determine important variables that can predict for the species’ occurrence.  I really enjoyed chatting with David about his project, and it brought me back to a time when this sort of thing played a much larger role in my life.

The research being carried out by David and Chris is important.  Alligator snapping turtles populations have declined dramatically, and they are now uncommon or rare throughout much of their range.  Factors influencing this decline include a loss of high quality habitat and over-harvest for its meat, which has long been considered a delicacy.  As a result, they are now protected in many states where they occur, including Texas.  This protected status has not stopped illegal poaching, however, and many animals are still taken this way, or caught on trotlines set callously in their habitat.  Once hooked on these lines, the turtles suffer a slow, agonizing death.

When initially captured or threatened, the loggerhead generally opens its mouth wide, and will snap at anything that approaches too close to its head.  Believe me when I say, this is a very effective intimidation tactic.  Those jaws slammed shut with bone-crushing force.  Those powerful jaws play a very important role in capturing prey in their murky aquatic habitats.  Alligator snapping turtles have lingual lures – specially adapted tongues shaped like worms that the turtles wriggle about while waiting motionless with their jaws wide open.  When some unsuspecting fish moves into to capture this false worm, the snapper’s mouth slams shut with blinding speed and crushing force.

As impressive as this gaping threat display was, I was really happy to capture images of the gator turtle with her mouth closed, in a more natural looking pose.  We spent a few minutes photographing and admiring this incredible animal.  We then set her near the stream’s edge, and walked as she slowly made her way back into the water and disappeared into the deep.

Spending time with this modern-day dinosaur was an incredible experience, and I was very grateful for the opportunity to get to know David, Laura, and John Michael and learn more about the important work they’re doing.  It made me nostalgic for my days as a field biologist, but fortunately my current position does provide opportunities to be involved in research, specifically aimed at conservation of wildlife and plant communities related to transportation activities.  I hope to join David and crew again in the field at some point, and very much look forward to what they learn about the ecology and natural history of this keystone species.