A HUNT FOR BIG TREES
Small patches of ancient timber do remain in the Mississippi Delta, but these are few and far between. As I have found, the Tensas, sadly, holds none at all. So I head to a remnant old-growth patch in northeastern Mississippi, in Delta National Forest, which holds a mix of forest and nonforest habitats and is surrounded by row-crop agriculture, as one expects in the delta. From Lake Bruin, it takes me a bit more than two hours to find the gravel road to Sweetgum Research Natural Area. I set up my tent in its parking lot, and I head into the forest to look for big trees.
This area—about forty acres tucked amid sixty thousand acres of national forest—features ancient Sweetgums scattered throughout a single old-growth plot. The plot is species-rich, boasting oaks, Prickly and Green Ash, Honey Locust, and Southern Hackberry. Many of the Sweetgums top 130 feet in height, and several have trunks exceeding four feet in diameter. The largest Sweetgum I saw, 135 feet tall, was more than five feet in diameter at breast height. No doubt, these four-hundred-year-old trees hosted foraging Ivory-billed Woodpeckers at some time in their long lives. It was enthralling to stand beside the forest giants and think back two centuries, when they were already postmature canopy trees. Moreover, it was sad to think that across the length and breadth of this immense tract of national forest, only a handful of old-growth trees were preserved for posterity. What were foresters thinking when they did not set aside larger samples of the original ancient forest? Should such strategic set-asides not be a mandate of any “national” forest? Those overseeing the government management of our western forest lands, which still harbor ancient tracts, need to take note.
I spent a day and a half birding and naturizing in Delta National Forest. The access road cut through a fine stand of secondary forest about a half-mile in extent, through which I biked to a wooded swampland just to the north. A very wary Red Fox—not one of those tame residential creatures I knew from home—skittered across the road in front of me. At the forest’s wetland, Mississippi Kites played about in the sky over the prime swamp habitat. Back at the parking-lot campsite, by the stand of old trees, I heard a Prothonotary Warbler, Kentucky Warbler, Acadian Flycatcher, Veery, and Wood Thrush. I had expected to hear many more forest-dwelling birds, but instead the soundscape was dominated by the voices of lots of nonforest species, such as the Carolina Wren, Great Crested Flycatcher, White-eyed Vireo, and Mourning Dove. And, just as at every forest edge in the early morning, flocks of Indigo Buntings were coming up out of the roadside grass. Huge numbers were moving northward to their breeding territories in the middle of the country—I could not escape the little blue songbirds.
A male American Redstart, singing on territory, was my tenth quest species. It darted about in the understory at the edge of the forest, chasing down winged insects among the low shrubbery. Breeding from southern Louisiana north to Labrador and the Yukon, this is one of the most familiar forest-dwelling warblers in North America, beloved for its confiding and active demeanor, its bright and upbeat rapid song of slurs and chips, and the male’s plumage of black, orange-red, and white—a bit reminiscent of an undersized Baltimore Oriole. I clearly recalled that I’d seen the species for the first time in the early 1960s in the tall woods on Bill Johnson’s farm, north of Baltimore. I’d whooped with delight when the male warbler danced in front of me, showing off his bright oriolelike colors.
Foraging in a shrub at the forest edge near my tent was another surprise: a Ruby-crowned Kinglet. I had forgotten that they wintered so far south. In fact, this tiny, high-energy species was a sort of fellow traveler on its way to the far north: it, too, was headed to Ontario, where it would prove to be one of the commonplace species in my little-known destination, the upper reaches of Kenora District in northern Ontario. The kinglet is not a wood warbler, but it is certainly reminiscent of one, with its olive plumage, white wingbars, and pale eye-ring. In addition, it’s as hyperactive as a warbler. Weighing a mere quarter of an ounce, this kinglet is North America’s second-smallest songbird—only its cousin, the Golden-crowned Kinglet, is smaller. Although they were not as eye-catching as the Indigo Bunting, swarms of kinglets also would be leading me northward, and welcoming me at the apex of my journey with their bright, bubbling songs in a few weeks’ time.
It was almost time for me to leave the vast alluvial delta of the Mississippi. The delta continues to support bottomland forest in the annually flooding low country of the many tributaries of the Mississippi, including the Tensas, Atchafalaya, Red, Black, White, Ouachita, and the Saint Francis—good news for migrant songbirds. The flat alluvial country penetrates northward into Missouri and Illinois, near the confluence of the Ohio and the Mississippi, and the delta ends where the Ozarks rise up in eastern Missouri and the Shawnee Hills break up the landscape of southern Illinois. Bluffs and hills announce the inevitable transition from the black-soil South to the upland North, where the Mississippi winds between tall, rocky banks vegetated with handsome and well-drained upland hardwood forest. Before I headed to the North, however, I needed to explore two additional Deep South songbird habitats: the piney woods of Texas and Arkansas, and the associated cypress swamps in those two states and in Missouri and southernmost Illinois.
FIVE
Piney Woods and Cypress Swamps
Late April 2015
Red-cockaded Woodpecker
Out of the luminous mist in which the trees showed like ghosts I heard the forgotten voice of yesteryear—once and silence, again and silence, and again—at regular intervals from a grove of trees, the little buzzing, ascending wisp of song that the parula warbler gives off.
—LOUIS HALLE, Spring in Washington
The southern pinelands—or piney woods—cloak tens of millions of acres in the South. Migrant songbirds breed here, as do several rare and localized resident bird species, all prime incentives for me to visit the area. Pines grow in abundance in the uplands, but down in the flooded swamplands, the cypress flourishes.
Much of eastern Texas, western Louisiana, and southern Arkansas hold piney woods, and additional southern pinelands range from central Mississippi and northern Florida northeast to southernmost Virginia. Whereas the delta, with its deep black soils, supports row-crop agriculture, the pinelands’ sandy soil generates timber and pulpwood. As a result, after they are logged, these areas are quickly recycled back into monocultures of production pine forest. The good news is that the pinelands remain in a forested state. The bad news is much of this pine-forest acreage is overmanaged for timber and pulp, with relatively little left in its natural condition. Nearly gone are the magnificent and parklike Longleaf Pine savannas of the South, where tall pines once towered over sun-dappled grasslands. The open nature of those woodlands was maintained by periodic wildfire, but over the decades, as the pines were harvested for all sorts of construction tasks, from shipbuilding to flooring, wildfire was suppressed. Now less than 1 percent of that fire-dependent habitat remains.
Cypress, meanwhile, prospers in the standing blackwater swamps of oxbows and backwaters along the many tributaries of the Mississippi, from Louisiana north to southern Missouri and southernmost Illinois. Just as the piney woods are favored habitat for an array of songbird migrants, the cypress swamps attract their own songbird specialists. I searched for these birds with the help of various local naturalists as I traipsed from Texas and Arkansas to Missouri and Illinois.
ORIENTATION: THE INTERNAL COMPASS
As I moved about from site to site, I sought to get a sense of this large inland region. The wood warblers I followed did the same thing, not using maps and GPS as I did but instead employing specialized sensory faculties to orient themselves with respect to where they were and where they needed to go to arrive safely at their breeding grounds. Orientation is pretty simple in theory—it is the ability to distinguish north from south, and east from west. It essentially means that you have access to a compass. There is no doubt that migrant songbirds have the capacity to orient themselves properly with regard to com
pass direction. The mystery, of course, is how they manage to achieve this without having access to an actual compass.
Yearling songbirds in their northern breeding habitat first learn to orient in the late summer, when they must head south to their winter habitat for the first time. First they experience an innate urge to disperse from their natal territory, based on the birds’ internal annual calendar. This calendar is kept in calibration by external astronomical cues, including day length and the path traced by the sun across the sky each day. The birds also possess the innate ability to determine direction—an internal compass. What is the nature of this compass? We now know that birds possess several tools to orient themselves. The first is the sun. By tracking the sun’s path across the sky, a bird, with knowledge of the season of the year and the time of day, can orient itself to a proper compass direction. Second, birds can also detect the plane of polarized light in the sky—and thus the position of the sun—even after sunset or on cloudy days.
That said, many migratory songbirds migrate at night, well after the sun has set. What then? Songbirds use the starry night sky to determine compass direction. In their first summer of life, birds learn how to detect the rotation of the constellations around the North Star to determine north. They subsequently can use the pattern of the constellations to locate the North Star, from which they can orient themselves without having to detect stellar rotation.
But there’s more. Birds possess an internal magnetic compass: the ability to detect the lines of the earth’s magnetic field, which allows them to determine magnetic north. Birds and many other animals have small particles of magnetized iron (magnetite) in their bodies that apparently aid in this ability to orient themselves. In pigeons, the magnetite is located between the brain and the skull. Other research indicates that birds are able to generate magnetically sensitive internal chemical reactions that can serve a compass function.
Thus birds appear to have a minimum of four separate tools that provide compass orientation and guide their travels. They rely upon these multiple capacities because, just like a car with both a parking brake and a pedal brake, it is good to have backup systems for critical tools that one depends on in life-or-death situations.
Yet birds have still another trick up their wings. They can tell where they are on earth, not merely how to get there. In a later section, we’ll discuss that internal GPS capacity.
CYPRESS AND BIGFOOT
My first stopover is Caddo Lake State Park near Karnack, in northeastern Texas, not far from the border with Louisiana and Oklahoma. I’m here to spend five nights at cypress-filled, 25,400-acre Caddo Lake, which straddles the Texas-Louisiana line. Karnack, so small that it has no downtown, just a couple of intersections where convenience stores have settled, attracts visitors both to the state park and to Caddo Lake National Wildlife Refuge, where I plan to hang out with a university group doing a natural history field survey.
I set up camp in a corner of the park that I have all to myself: a spot in tall bottomland forest at the edge of a blackwater arm of the lake. Cypress trees rise from the water on one side of the tent, and great oaks on terra firma provide shade from the scorching Texas sun on the other. I’m deep in the woods near where Big Cypress Bayou flows into the lake. Soft green light filters onto the picnic table, and a male Prothonotary Warbler sings in a nearby tree. I eat my lunch watching the orange-tinted songster declare his territory in his unmusical, repetitive lisp.
Caddo Lake State Park was created in 1933, when Lady Bird Johnson’s father and several other local landowners contributed the property needed for the reserve. Using the National Park Service’s “natural design style,” the Civilian Conservation Corps (CCC) constructed the park roads and buildings, completing the project in 1937, at the height of the Great Depression. A number of the rustic CCC buildings, made of timber and stone sourced locally, still stand in the park today.
Caddo Lake is famous for a few reasons. First, it has been identified as a wetland of international importance through the Ramsar wetlands treaty (which designates globally significant wetlands around the world to encourage their conservation). Second, it is a favored weekend hangout for Eagles drummer Don Henley, who grew up in Linden, a bit north of Karnack. Henley founded the Caddo Lake Institute to foster conservation of the lake’s ecosystem and to assist with reintroduction of the endangered American Paddlefish to the lake’s waters. He is an example of a private citizen, albeit a well-known one, who has done more than his share to support conservation of habitat and endangered species because of his love for a verdant corner of the world that happens to be in his childhood backyard. And because northeastern Texas is rich in fishermen, Caddo Lake’s Large-mouthed Bass, White Bass, Crappie, and Sunfish are other reasons for its popularity. The lake is perfect for kayaking and birding as well.
Caddo is a large blackwater lake adorned with huge stands of mature Bald Cypress, an antediluvian swamp conifer of the Deep South. The big trees, festooned with Spanish Moss, are its most remarkable and otherworldly feature, and, of course, they capture the attention of every visitor. Ringing the shallows, this cypress is a tree apart. A strange conifer that drops its leaves in autumn, it has knobby “knees” (function unknown) that rise out of the dark water like woody stalagmites. The tallest cypresses approach 150 feet in height, and the thickest trunks exceed sixteen feet in diameter. The most ancient of these cypresses is more than fifteen hundred years old. The wood of old-growth cypress is valued for its resistance to rot, and thus much was logged out by the early twentieth century.
Gazing at its ancient-looking cypresses and black water, one could imagine that Caddo Lake is a geologically ancient hydrological feature. Apparently not. The lake formed when Big Cypress Bayou was dammed by a landslide set off by the massive New Madrid earthquake of 1811. Thus Caddo Lake is a recent creation. In fact, geologists tell us that, in general, lakes are ephemeral features on the landscape, so perhaps this should not be a surprise.
Caddo’s unearthly looks have given rise to still another reason for its fame (one that I speculated about at my campsite). There have been rumors of hundreds of sightings of Bigfoot, otherwise known as Sasquatch, in and around Caddo Lake since 1965, which is perhaps why one shoreline community sports the rather remarkable name of Uncertain. In 2015, the Animal Planet channel sent a film crew to do an episode of Finding Bigfoot that featured the obligatory nighttime field search for the creature in the Caddo Lake area. (Why do these searches always take place at nighttime, with night-vision head gear? It would be easier to locate the creature by setting out a few dozen camera traps along well-worn game paths.) The search team was unable to capture Bigfoot on film, of course, but they did interview local residents who claimed to have glimpsed the big primate, a species probably considerably less abundant than the endangered American Paddlefish.
The paddlefish is actually the strangest creature that we know for sure lives here. A primitive ray-finned fish related to the sturgeons, it has a prominent, long, paddle-shaped snout and can boast relatives dating back 300 million years. Over a paddlefish’s thirty-year lifespan, it can reach a length of five feet and weigh as much as 150 pounds. The declining species inhabits the Mississippi basin and is primarily a filter feeder. Its population has dropped (as is the rule rather than the exception for large fish) as a product of overfishing, habitat destruction, pollution, and poaching for the fish’s caviar, which is an inexpensive substitute for Beluga Sturgeon caviar from the Caspian Sea. Henley’s Caddo Lake Institute has been working to reestablish American Paddlefish in Caddo Lake in partnership with the Texas Parks and Wildlife Department and the U.S. Fish and Wildlife Service. These groups have worked with the Nature Conservancy and U.S. Army Corps of Engineers to ensure that water flow from upstream is sufficient to provide suitable habitat for this odd and ancient fish. Time will show whether their important experiment is a success. At Caddo Lake State Park, I saw plenty of wildlife but not a single paddlefish.
STATE PARKS: FORGOTTEN GEMS
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State parks are America’s overlooked jewels. Most people know them as good places to camp, birdwatch, and fish, and typically state parks have infrastructure that makes staying at one a pleasure. At Caddo Lake State Park, for example, I camped in a tent in the forest, and yet each morning I could take a hot shower and shave in a spanking-clean bathhouse. Yet sometimes these parks—and there are 6,600 of them across the country—get a bad rap because they are not very wild or not terribly special biologically. But their glory is that they are local, accessible, and comfortable, and in many instances they offer the best of regional nature to visitors, many of whom come from nearby. Not to be confused with national parks, state parks’ main purpose is to offer local residents a place to get away on a weekend or a Labor Day holiday. The thousands of state parks across the United States feature lakes, wetlands, rivers, forests, and mountains that offer recreation for us all—at close range and at minimal cost. Their success is measured by the fact that they receive nearly three times as many visits per annum as national parks. For most citizens, state parks are where they first learn about and encounter nature in a welcoming setting.
The second morning at Caddo Lake State Park, I noted a public bird walk was offered by park naturalist Mia Brown, and I joined the group of about ten participants in an hour-long introductory course in field ornithology. None besides Brown and me had ever been birdwatching, and she was able to introduce the newcomers to birding in a welcoming way. She had binoculars and field guides in the back of her truck, and the group was very enthusiastic as we looked for birds from a long dock projecting over the lake. Barn Swallows, an Eastern Phoebe, a Green Heron, a Great Egret, a male Prothonotary Warbler, and a male Summer Tanager delighted the group. Back at the truck, Brown took a small roll of paper towel off the front seat. She carefully unrolled it and showed the group a freshly killed Magnolia Warbler that, she explained, had struck her office window and fallen dead upon the sill. The bird was in perfect condition, and the children in the group were moved by its fragile beauty. Brown noted that windows are major bird killers: the birds see a reflection of green vegetation, attempt to fly through the space, and hit the pane. Her take-home point was that the human environment poses threats to birds.
North on the Wing Page 10