Generally speaking, when I set out to explore nature I’m seeking the most pristine places I can find.  These places are ancient – old growth forests with towering trees or virgin prairie on a bed of soil that has never been plowed.  I like to see things the way they may have looked prior to European settlement, and transport myself to a distant, wilder time.

But if I chose to ignore those more disturbed habitats, I would be robbing myself of a wealth of beauty and diversity.  In fact, there are many species that have evolved to take advantage of early successional communities created in the wake of some disturbance.  Historically, these habitats may have formed by a variety of means.  For example, when a massive tree falls in an old growth forest.  Imagine ten tons of timber crashing to the earth.  A tree like this could take out a swath of forest totaling a third of an acre or more, especially if it brings adjacent trees down with it.  This new gap in the canopy would undergo the process of succession, responding much the way a fallow field does when it slowly reverts back to woodland.

The patch of disturbed land could increase significantly in the face of some natural disaster.  A tornado could take out a swath of forest hundreds of feet wide and miles long.  A severe hurricane could level acres of forest near the coast, and a wildfire could remove forest cover on the scale of thousands of acres.

Events like this are particularly important in the eastern United States, where much of the landscape was historically forested.  There existed, however, a multitude of non-forested communities interspersed among the old growth timber.  These included prairie inclusions, barrens, and similar habitats that were kept open by a variety of factors including soil conditions, grazing by American bison, and regular wildfire.  If one of these communities went too long without the introduction of some natural disturbance, it would begin to revert back to forest through the process of succession.

Today, however, the U.S. is far removed from the natural eden it was just a few hundred years ago.  That is not to say, however, that suitable habitat for these disturbance dependent species no longer exists.  Take the Prairie Warbler (Setophaga discolor), for example.  The “Prairie” in its name is misleading, as this is not a species of prairie or grassland habitats, but rather one of those early successional habitats described above.  They breed throughout much of the eastern U.S., from Maine to east Texas.  Here I most frequently observe them in regenerating pine stands 5 to 10 years after harvest.

A male Prairie Warbler sings in defense of his territory.

These sites undergo succession much in the way a forest would following some natural clearing event.  First a variety of grasses and forbs will invade.  Soon after the pines will sprout.  Before long, however, the trees will grow to tall, the canopy will close, and the habitat will no longer be suitable for the Prairie Warbler.

The ephemeral nature of these ever changing habitats means that species like the Prairie Warbler do not have a reliable territory to return to each year, and must seek out new breeding sites once their old territories are no longer suitable.  I speculate that, given a certain element of unpredictability with their preferred habitat, Prairie Warblers, and other disturbance-dependent bird species likely experience local cycles of “boom and bust”, potentially increasing in numbers following large disturbance events, and decreasing as the disturbed areas reach later successional stages.

Another species found in these disturbed habitats is the Yellow-breasted Chat (Icteria virens).  The chat was once considered our largest warbler species, but recent research indicates that is more closely related to blackbirds, and it has been placed in its own family (Icteriidae).  Chats are well known for their loud, varied songs which consist of a variety of raucous warbles, whistles, rattles, and more.  The males perform elaborate courtship displays on the wing, slowly descending in choreographed fashion.

Yellow-breasted Chats can be found throughout much of the contiguous U.S and portions of Mexico and southern Canada.  They are less specific in their habitat preference than prairie warblers, and can be found in a variety of disturbed habitats.  They are easy to hear, but difficult to see, often skulking low in dense vegetation.

Unlike the chat, the Painted Buntings (Passerina ciris) maintain a visible presence in their territory, frequently singing from the highest perches available.  These sparrow-sized songbirds are considered by many to be among the most beautiful birds in the country, and they certainly leave a lasting impression on those fortunate enough to encounter them.  I’ll always remember the first one I saw birding with my mom.

The Painted Bunting breeds in the south-central states, along the Atlantic coast in the southeast, and portions of northern Mexico.  They can be found in a variety of disturbed habitats, as long as there is some shrub or small tree component.

Though it lacks the varied color scheme of its cousin the Painted Bunting, the Indigo Bunting (Passerina cyanea) is no less striking.  With its metallic cyan plumage, this is one of my favorite birds to observe in the spring and summer here in the Pineywoods.

Indigo Buntings breed throughout much of the eastern U.S. with a few isolated populations in the southeast.  Though I most often associate this species with disturbed areas, I also frequently observe them in high quality habitats such as mature longleaf pine savannas.  This is not entirely surprising, however, as these once vast longleaf pine forests depend on regular disturbance to maintain an open understory and rich herbaceous layer.

Another disturbance loving blue beauty is the Blue Grosbeak (Passerina caerulea).  They are quite similar to the Indigos, but can be differentiated by their heavier bill and chestnut wing bars.  To me, the blue of the grosbeak is more cobalt, and the bunting more cyan.

One might encounter Blue Grosbeaks across the southern and central United States and northern Mexico.  They can be found in a variety of shrubby habitats.  In the eastern U.S. this usually means areas that have undergone some recent or continuing disturbance, however further west this can include mature desert scrub and woodlands.

The image below is of a regenerating pine plantation where I observed Prairie Warblers, Yellow-breasted Chats, Painted Buntings, Indigo Buntings, and Blue Grosbeaks.  Also present in the area were White-eyed Vireos, Northern Cardinals, and Northern Mockingbirds.  In East Texas, Northern Bobwhites may also utilize habitats like this, though they have all but disappeared from the Pineywoods.

When a disturbed habitat occurs in close proximity to water, additional bird species may be encountered.  The Eastern Kingbird (Tyrannus tyrannus), for example, inhabits disturbed areas such as marshes, shrublands, forest edge, and riparian areas, and are generally closely associated with water.  Kingbirds are so-named for the voracity with which they defend their territories against intruders of all shapes and sizes.

Perhaps our most familiar denizen of wet, disturbed habitats is the Common Yellowthroat – the little masked crusader that announces its presence to the world with its trademark wichity-wichity-wichity song.  Though they can be found away from water, yellowthroats are most commonly associated with weedy or scrubby habitats on the margins of marshes, ponds, and streams.

The Common Yellowthroat is a member of the Warbler family (Parulidae).  They are widespread in the U.S., Canada, and portions of Mexico.  We are lucky enough to have a few birds present year round in the southern half of the Pineywoods and on the Upper Texas Coast.

In modern times, areas of significant disturbance have increased dramatically as old growth forest has been cleared to make way for pasture, agriculture, development, and managed timber.  It is clear that having some early and mid successional areas on the landscape is beneficial to biodiversity on a macro scale, however it becomes a concern when this occurs over a large scale, which is too often the case.  They key, like in so many things in life, is moderation.  Fortunately, modern forestry practices have improved dramatically, and programs like the Sustainable Forestry Initiative promote managing the landscape as a patchwork of successional stages.

Despite an increased abundance of disturbed areas across the U.S., many of these bird species remain uncommon and some are declining.  The problem is, disturbance in and of itself is not enough.  The nature, and method of the disturbance is important.  Areas that undergo intensive herbicide or pesticide use, for example, are not suitable breeding sites for birds.  Additionally, areas that are too heavily managed, where woody vegetation is not allowed to reach appropriate heights are similarly unproductive for all but the most generalist of species.

As lovers of biodiversity, it is important that we support and promote best management practices in land disturbing activities, so that we can simultaneously provide a sustainable resource and enhance local biodiversity.

 

 

Imagine, for a moment, that you are standing with your feet firmly planted in the dark soil atop a gentle knoll, surveying an undulating sea of grass that stretches as far as the eye can see.  You are somewhere north of Fort Worth, in a time before the land was forever scarred by asphalt, steel, and an insatiable need to bend the land to meet the will of man.  At a high point, you may be standing only a few feet higher than your surroundings, yet your view is unobstructed.  A lone, gnarled oak or mesquite may stand here or there in defiance of the forces that break any woody invader that tries to set roots in the prairie, and far in the distance a dark line of trees lines a gully that drains the plain.

The sky is darkening and rising columns of clouds in the distance give you pause.  Yet you wonder, for a moment if the faint roar that you hear is the advancing thunder, or the furious poundings of thousands of hooves as a herd of bison takes flight.  The wind hits, borne by the impending storm, and sends the countless wildflowers into motion, creating a kaleidoscopic blur of color.  If you could transport yourself to this place and time, you would be standing in the once vast tallgrass prairie of north-central Texas that served as a southern extension of the Great Plains that fueled and shaped our developing nation.

The truth is, we will never be able to know what these prairies were like prior to European settlement.  We can piece it together to some degree based on the journals of early explorers and settlers, however there were no doubt aspects of the landscape, flora, and fauna that were not captured in what they scribed.  When Anglo cultures first arrived, the landscape had been shaped by centuries of inhabitancy by Caddo, Wichita, Kichai, Osage, and other indigenous tribes.  Though their impact on the land was more harmonious than the people that succeeded them, they helped maintain the open nature of the prairie by setting fire to control vegetation and direct game movements, supplementing the naturally occurring lightning-ignited conflagrations that were common in the region.  Many of the tribes of the region also practiced small-scale agriculture, which would have no doubt altered the nature of the plains.

It has always been a fantasy of mine to experience Texas in these pre-settlement times.  If I could, I would start in Galveston, and make my way north, through the extensive coastal prairies, where the only variation in elevation were minuscule wind-sculpted mima mounds, and a matter of inches resulted in an entirely different cast of plants, and meant the difference between dry and wet feet.  Continuing north, I expect I would watch the timber hugging the larger streams become broader and broader, piercing the prairie until I was immersed in a wet savanna surrounded by towering longleaf pines.  As I hit the Kisatchie Wold, the terrain would change to become rolling, with steep ravines and exposed geologic outcrops.  Here the forests would become diverse, and stratified based on slope position.  I may still encounter a prairie here or there, particularly in the form of a sandstone barren over the Catahoula Formation, or a Blackland inclusion on the Fleming Formation.

As I reach the northeastern corner of the state, the trees would begin to thin again as I transition into the Post Oak Savanna.  In Bowie, Red River, and Lamar Counties I might be lucky enough to break into a silveus dropseed prairie.  It would be interesting to know if certain species that are now exceedingly rare in the state, like Castilleja coccinea, Parthenium integrifolium, and Platanthera lacera were more common then.  Eventually the sandy soils of the post oak would give way to the fertile black clays of the legendary Blackland Prairies.  This narrow band of tallgrass prairie is perhaps the most altered of all of Texas’s ecoregions, forever changed by development, agriculture, and the removal of bison and fire.

It wouldn’t be long before the black clays began to lighten and the influence of chalky limestone became evident.  Scattered trees would begin to return as I entered the eastern Cross Timbers.  My journey through this mingling of prairie and stunted woods would be short-lived as well, and soon I would come to my little knoll in the Fort Worth Prairie, the northern expression of the expansive Grand Prairie, which also contains the Lampasas Cut Plain to the south.

The adventure of this blog begins in the Blackland Prairie of Collin County, above virgin soil in what my friend David Bezanson of the Nature Conservancy calls “the best Blackland Prairie left in Texas.”  These blacklands once stretched 300 miles across the Lonestar State, and occupied over 10 million acres of her surface. They sustained massive herds of bison, prairie chickens, Texas Horned Lizards and numerous other species that have vanished from the region in the face of westward expansion. The black clays that lent the region its name formed as underlying cretaceous marine sediments were broken down through weathering and erosion over millions of years. This resulted in the formation of some of the most fertile lands in the state – lands that were quickly exploited for their richness and within a matter of generations, all but a fortunate handful of sites were forever changed. By most estimates, less than one percent of the historic Blackland Prairie contains soil that has never been broken by the plow. Of those precious remaining places, few are protected and even fewer receive the regular disturbance that they need to thrive.  This was one of those precious few remaining places where one can imagine the way things once were.

On a gray day in mid April, the towering blooms of Blue Wild Indigo (Baptisia australis) reached skyward and brightened the gloom.  Native cultures utilized this striking member of the pea family for a variety of purposes.  Some portions of the plant are toxic, however the roots were used to treat a variety of ailments, including nausea, toothaches, and inflammation.  The milky sap from the roots was also used to make a bluish dye.

The Prairie Penstemons (Penstemon cobaea) were just coming into bloom.  Their showy flowers may reach over 2 inches long and can be various shades of white, pink, and purple.

Engelmann’s Daisies (Engelmannia peristenia) were also beginning to unveil this season’s flowers to the pollinating world.  This member of the sunflower family is a classic open country plant of the southern plains, and is still common in prairie remnants and areas that are not too aggressively managed with plows and herbicide.

Each azure bloom of the Prairie Celestial (Nemastylis geminiflora) lasts only a few hours, opening in late morning and closing by late afternoon.  This member of the iris family is a true prairie gem that must have left an impression on early naturalists visiting the region.

Just west of the Blackland Prairies lies the Eastern Cross Timbers, where a band of sandy soils supports Eastern Redcedar and a variety of oak species.  Accounts from early settlers to the region indicate that this was not a homogeneous region of timber, but rather a varied landscape with numerous prairie inclusions, savannas, and areas of nearly impenetrable woodland.  Pre-settlement, this woody intrusion into the prairie was short-lived, and west bound travelers would soon reach the Grand Prairie.

The plant and animal species that occurred in the Grand Prairie are similar to those of the blacklands, though certain species are more common in one or the other.  The geology, however, is markedly different.  Chalky limestone substrates are more prevalent in the Grand Prairie, and deep clays are infrequently encountered.

Like the Blackland Prairies, the Grand Prairie has been altered almost beyond recognition.  In many areas the prairie here would have stretched from horizon to horizon, and beyond.  Massive herds of bison occurred here, as evidenced by this excerpt from Narrative of an Expedition Across the Great Southwestern Prairies: From Texas to Santa Fé, a work by George Wilkins Kendall with many references to the prairies of north-central Texas:

“I have stood upon a high roll of the prairie, with neither tree nor bush to obstruct the vision in any direction, and seen these animals grazing upon the plain and darkening it at every point. . . . In the distance, as far as the eye could reach, they were seen quietly feeding upon the short prairie grass. .”

The Grand Prairie also marked the western extent of the Pronghorn, a prairie icon now long gone from the region.  Other species, like the Texas Horned Lizard have much more recently disappeared, and some species that are still common, like the Woodhouse’s Toad, show signs that they may be soon to disappear.

Being from the Pineywoods, I’m used to photographing species that are at the western edge of their range – species typical of the vast deciduous forests of the eastern U.S. In the Grand Prairie, however, a number of species reach the southeastern extent of their range.  One such species is the Purple Locoweed (Oxytropis lambertii) which occurs in the Great Plains and portions of the Rockies.  I first photographed this species over a decade ago in a Moraine Prairie in Rocky Mountain National Park, and I must say it was even more exciting finding them in perfect bloom in the Grand Prairie just three hours from home.

The northern expression of the Grand Prairie is often referred to as the “Fort Worth” prairie and occurs in a relatively narrow band between the Red River to the north and the Brazos River to the south.  These once vast expanses of grass and wildflowers were said to be virtually devoid of woody vegetation, and likely bore a striking resemblance to the stark setting of the Great Plains familiar to most of us.  The “big three” prairie grasses – Little Bluestem (Schizachyrium scoparium), Big Bluestem (Andropogon gerardii), and Indian Grass (Sorghastrum nutans) were prevalent here.  And occurred alongside a diverse host of forbs and other grasses.

In mid-April, vast drifts of Eastern Shooting Star (Dodecatheon meadia) appeared, like thousands of meteors bearing down on earth spurning pink flames as they clash with the atmosphere.  The prairie-dwelling shooting stars of Texas are bright pink, in contrast to the white they display throughout the majority of their range.  Dodecatheon meadia occurs across much of the eastern U.S., occurring in a variety of habitats over calcium-rich substrates.  They reach the western extent of their range in the prairies of central Texas.

It is hard to imagine a more photogenic wildflower than an Eastern Shooting Star in prime condition.  But like the meteors that dissipate before they can reach the earth’s surface, their appearance each spring is far too fleeting.  Though uncountable populations have undoubtedly been lost, there are still a few places where one can glimpse the splendor of a meadow with thousands of tiny pink meteors descending into the prairie.

Among the shooting stars were the blooms of a complicated little plant, the Prairie Paintbrush (Castilleja citrina).  This hemiparasitic plant derives some portion of its energy and nutrients from the roots of other plants.  C. citrina is part of a complex of paintbrush species that includes the closely related Purple Paintbrush (Castilleja purpurea) and Lindheimer’s Paintbrush (Castilleja lindheimeri).  In fact, C. citrina and C. lindheimeri were previously considered varieties of C. purpurea, however subtle differences in flower color, plant morphology, and habitat preference has resulted in the designation of distinct species.

There are certain areas, however, where these species occur in close proximity.  In the Fort Worth Prairie, the area separating C. citrina and C. purpurea occurs right along the Wise/Montague County line.  North of this line, nearly all individuals observed are C. citrina, and to the south C. purpurea abounds.  There is a narrow band of hybridization, as evidenced by the variety of colors and shapes in the image below.

Just south of this line, however, the Purple Paintbrush paints the prairie.  Seeing the beauty above, it is easy to forget the tumultuous battle occurring below the soil as the roots of the paintbrush wage war on other prairie plants.

Another charming prairie plant is the Fringed Bluestar (Amsonia ciliata), its blue blooms echoing the sky.  The bluestars’ tubular flowers are pollinated by a variety of moths and butterflies, and migrating hummingbirds.

Though the Fort Worth Prairie is generally flat, topographic relief does occur in the form of cuestas – small hills that rise gradually to one side, and drop off abruptly to the other.  Cuestas are formed as more erodible geologic layers have weathered away, revealing the ends of more durable adjacent layers.  The vegetation varies from the top of the cuesta, down the slope to the bottom due to a variety of factors including soil conditions, moisture levels, and natural fire patterns.

The rich prairies near the Red River once served as breeding grounds for the Upland Sandpiper.  This once abundant prairie shorebird suffered precipitous declines at the hands of market hunters in the late 1800s and early 1900s.  As their numbers dwindled, so did their habitat, and the bird faced a very bleak future.  Fortunately, conservation laws were enacted early in the twentieth century that put an end to market hunting, and their numbers appear to have been slowly rebounding since.  Despite this, they have still yet to return to much of their former breeding range.  Upland Sandpipers were known to nest in the Fort Worth Prairie in the nineteenth century.  On our visits to the region, Caro and I have seen many during migration during April and May.  I hold out hope that over time, this special prairie bird will again colonize the region.

The beauty of a vast prairie abloom with wildflowers is a thing of pure beauty.  Few species are as showy as the Prairie Hyacinth (Camassia angusta) blooming en masse.  This prairie dweller is a close relative of the more familiar Wild Hyacinth (Camassia scilloides), and is best differentiated by bloom time, and the persistent sterile bracts present on C. angusta.

Our journey through the prairies of North-Central Texas ends much as it began, pondering their past, present and future.  Caro and I had spent a few glorious spring days in these prairies, and before we returned to the forests of East Texas, we stopped at one final meadow, adorned with blooming shooting stars.  I made an effort to immerse myself in the moment; to take in all aspects of the prairie:  Her sights – gently swaying hues of pink, green, and brown; Her smells – damp earth and chemical compounds exuding from fragrant leaves; Her sounds – the subtle tune of grass in the breeze and a distant Meadowlark’s song.  Moments like this stir something within me.  They inspire me, and they make me feel a deep connection to the natural world.

As I sat there, watching the shooting stars sway in the wind as storm clouds coalesced and darkened the distant sky, I imagined the countless dramas that unfolded over the expanse of this prairie.  I imagined that surely a tornado or two passed over this spot.  It was hard to imagine such a placid place turned deadly by such an awesome force of nature capable of ripping the very grass from the ground.  And though I preferred to dwell on dramas natural in their nature, my mind couldn’t help but wander to those dramas wrought by man.  Like the wanton, systematic elimination of the American Bison – an icon that helped shaped our nation essentially extirpated in a single generation.  And they weren’t alone.  It was hard to miss the disappearance of wolves, bears, and mountan lions.  Less obvious were the prairie chickens that slowly vanished, or the Upland Sandpipers and other migratory birds that became less numerous each summer until one year they simply failed to return.  And we will never what botanical wonders were lost before they could ever be documented.  It was easy to despair and wish for what was once and will never again be.  But it was also easy to hope.  On our prairie tour, Caro and I had seen many incredible things – inspirational results from dedicated conservation efforts; rare plant communities that were thriving; and promising signs that some species that have vanished from our Texas prairies may one day soon return.

If prairies are important to you, as they are to me, please consider donating to conservation organizations like The Native Prairies Association of Texas and The Nature Conservancy in Texas.