North on the Wing

by Bruce M. Beehler

  Yet tension remains in the tug-of-war between exploitation and preservation. Before departing Crossett, I joined GP forester Don Sisson to make a pilgrimage to the Morris Tree, a locally famous three-hundred-year-old Loblolly Pine that is 56 inches in diameter and 117 feet tall—famous because it is the largest and oldest remaining tree in the Crossett environs. The Morris Tree exemplifies what presumably many Arkansas pines looked like before the arrival of Columbus. Standing by the great tree, I was humbled by its grandeur, but also annoyed that commercial foresters had not demanded that their companies set aside representative plots of virgin forest within every large forest block that they harvested for timber. Such preservation plots, useful sources of seed stock and cuttings for future reforestation activities, would have been very beneficial to silviculture science over the long term and would have also had substantial educational value. For timber companies to set aside representative samples of virgin forest would have been another form of conservation offset, but, of course, it is now too late for that in Crossett or anywhere else in the Southeast, where the virgin forests all have been converted to lumber, and those lands converted to monoculture plantations of young pines.

  THE RCW AND THE ESA

  On my last morning in Crossett, I head into the pinelands of Felsenthal National Wildlife Refuge. I hope to photograph the Red-cockaded Woodpecker, a species I have not seen since 1992, when I visited a pine plantation managed by International Paper in northern Florida. As I search for the bird, many hundreds of dragonflies patrol the gravel roads. So many odonates in one place! They remind me of the butterfly effusion I saw on Mill Road in the Tensas.

  The Red-cockaded Woodpecker (or RCW, as forest managers call it) colonizes only old stands of living pines that have a relatively clear understory produced by periodic wildfire. Only a bit larger than a Downy Woodpecker, the RCW has a big white cheek patch and abundant black and white barring on its back. The adult male displays a small narrow red slash behind the eye. It’s a small bird, but it has a big story.

  The RCW is an important part of the southern pine ecosystem because family groups of the bird excavate large numbers of nesting holes across their home range, perhaps to give group members a range of night roosts that help them avoid predators. These drilled-out cavities are subsequently used by other woodpecker species, Brown-headed Nuthatches, Great Crested Flycatchers, Eastern Bluebirds, flying squirrels, and even tree frogs.

  The RCW’s global population is now a mere 1 percent of its estimated presettlement population. Historically a specialist inhabitant of Longleaf Pine savannas, this ecologically sensitive species declined drastically with the conversion of virtually all the 90 million acres of its fire-associated old-growth Longleaf Pine habitat in the eastern part of the country. Its classification as an endangered species by the U.S. Fish and Wildlife Service in the 1970s created a firestorm of controversy among the large corporations that managed millions of acres of pine plantations between North Carolina and Texas. Keeping the RCW from extinction (and satisfying the requirements of the Endangered Species Act, or ESA) has required millions of dollars of investment by state, federal, and corporate entities. Today many southern pine forests are young and an absence of fire has created dense pine-hardwood mixes, but the woodpecker requires trees older than eighty years and an open midstory without the successional hardwoods that sprout up in the absence of fire. Things are complicated still more by the species’ social system, in which each breeding pair is assisted by offspring of a preceding year (called helpers); by each family group’s territory size (exceeding a hundred acres); and by the fact that even with the assistance of helpers, RCW reproductive output is not high. The RCW is one of an array of threatened species in the United States that is conservation dependent, meaning that its survival depends upon substantial ongoing intervention by humans (we’ll hear about another such conservation-dependent species—the Kirtland’s Warbler—later in the book).

  The Red-cockaded Woodpecker is a flagship species of the Endangered Species Act. Signed into law in 1973, the ESA mandates a strict set of rules for the management of lands holding species that the U.S. Fish and Wildlife Service identifies as endangered. For corporations that depend on exploitation of habitat-based resources, the presence of an ESA-listed species, such as a colony of RCWs, can have serious negative financial impacts. In the case of the timber and pulp enterprises, the presence of the woodpecker in a company’s piney woods requires the development of a management plan to ensure the protection of the birds. As with the Spotted Owl in the Pacific Northwest and the Piping Plover along the beaches of the East Coast, local citizenry came to hate what they thought of as “job-killing” wild creatures fostered by the ESA. Communities disliked the federal mandate that required local action for endangered wildlife; it was expensive and cost jobs. But over time, businesses have adapted and recovery plans have been implemented, and today the Red-cockaded Woodpecker is protected on federal, state, and private lands throughout its range across the South, and the species is no longer in decline. Two remarkable technical innovations have aided the RCW’s recovery from the brink. The first is wholesale translocation of family groups from areas with high densities of the birds to other areas of suitable habitat that lack the species. Birds are trapped at night, when they are in their roost holes, and safely released at the new site. Their transition to their new home is aided by the second innovation: the development of an artificial nest cavity, manufactured of molded fiberglass. These nest cavities can be readily placed in trees throughout a site that will receive a translocated colony to smooth their transition to a novel patch of pine woods. The RCW, of course, will never return to its original abundance, but with the mandated assistance provided by the ESA, it will continue to survive in its little colonies scattered through the piney woods of the South. It is a success story for the ESA.

  Yet finding the RCW at Felsenthal wasn’t as easy as I thought it might be. Instead I found an abundance of other woodpeckers, especially Red-headed and Pileated. Finally, stopping at a likely tree plot, I heard a telltale high-pitched sneeze. I looked up to see a single bird in female plumage busily scaling pine bark in search of food. She ignored me and my tripod. Periodically, she headed to her nest hole and fed offspring, which I could hear squeaking but could not see. They must have been quite young, as more mature nestlings typically poke their heads out of the nest hole to grab food from the parent’s beak. The hole, high in an old Loblolly Pine, was made obvious by the big, messy swath of milky yellowish sap that covered the bark around its perimeter. The adult birds scar the trunk to produce these sap effusions in order to keep predatory snakes from entering the nest.

  FELSENTHAL AND THE NATIONAL WILDLIFE REFUGE SYSTEM

  A few miles west of downtown Crossett, Felsenthal is among the federal properties where RCWs are being protected and managed. Established in 1975, the sixty-five-thousand-acre refuge boasts an abundance of wetland resources, including Felsenthal Pool and sections of the Saline and Ouachita rivers. The lowest-lying sections of the refuge support seasonally flooded swamplands that give onto cypress and hardwood bottomlands. The uplands are dominated by pinelands. Historically, the Caddo people occupied the area, and important archaeological sites are well preserved within the refuge.

  Felsenthal provides major local habitat for twenty species of wintering waterfowl, Blue-winged Teal, Black Ducks, Gadwalls, and Ring-necked Ducks among them. Bald Eagles concentrate at the refuge’s wetlands in winter, and its upland forests serve as important breeding habitat for some Neotropical songbirds and as productive areas for passage migrants headed to more northerly breeding grounds. Its small population of Black Bears is one of only a few such populations remaining in the Deep South.

  The National Wildlife Refuge System, of which Felsenthal is one unit, includes 521 refuges and more than 93 million acres of wildland habitat protected and managed for wildlife and game across our fifty states. Twenty million acres of this system have been declared as “wilderness” u
nder the Wilderness Act of 1964. Far more so than the national parks, the national wildlife refuges are important wildlife habitat for migratory birds, especially for waterfowl and Neotropical songbirds.

  The Mississippi Flyway is home to nearly a hundred of the refuges, encompassing nearly five million acres of protected wildlands. Most refuges here not only protect important wetlands resources, but also, as at Felsenthal, include an array of other productive wildland habitats useful for migratory birds. Most, but not all, of the refuges welcome visitors and provide trails and drivable wildlife loops so that birders, nature photographers, and the curious can get a look at America’s natural patches. In season, fishing and hunting are permitted in designated sections. I would visit twenty national wildlife refuges—each a critical component of wild America—during my backroads journey.

  MINGO AND JOINT VENTURES

  My next destination is Mingo National Wildlife Refuge, a 21,600-acre reserve situated where the eastern edge of the Missouri Ozarks meets the northern extension of the Mississippi Delta—a perfect place for migratory birds. I plan to meet American Bird Conservancy field scientist Larry Heggemann here, early in the morning, a few days after I depart Crossett.

  Mingo features all the goodies—cypress swamp, expansive marshy wetlands, grasslands, oak bottoms, and hilly and rocky upland forest. Centered on an ancient abandoned channel of the Mississippi River, the reserve also has a twenty-five-mile wildlife loop, perhaps the longest in any national wildlife refuge.

  Heggemann, with his thirty-plus years as a conservationist, is an expert on Missouri wildlife and a perfect guide at Mingo. More generally, I also wanted to learn about his work with joint ventures, or JVs: regional institutional partnerships working to conserve migratory songbird habitat in the various Bird Conservation Regions across North America. These regions are ecologically distinct areas with similar bird communities, habitats, and resource management issues, and they were delineated by the North American Bird Conservation Initiative, a continent-wide partnership that includes state and federal government agencies, nonprofit organizations, corporations, and tribes. JVs use state-of-the-art science to ensure that a diversity of habitats are available to sustain migratory bird populations. In the United States, eighteen habitat-based JVs address bird habitat conservation issues within their identified geographic zones. Four habitat JVs focus on ecosystems in Canada. And three species-based JVs, all with an international scope, further the scientific understanding needed to effectively manage a species or a group of species (the Black Duck, Arctic geese, and sea ducks). JVs have a long history of successfully leveraging public and private resources to draw partners together to focus on regional conservation needs. Since the first JV was established in 1987, JV partnerships have leveraged government-appropriated funds to help conserve 24 million acres of critical habitat for birds and other wildlife.

  Heggemann, I learned, is responsible for promoting habitat management, land protection, and policies and programs beneficial for birds of conservation concern in the Central Hardwoods Bird Conservation Region (CHJV), which includes parts of Arkansas, Missouri, Illinois, Kentucky, Tennessee, and Indiana. Heggemann works closely with state and federal agencies, NGOs, and other partners to seek opportunities to restore and manage natural communities that are critical to the needs of priority bird species on both public and private lands.

  The particular species that are conservation priorities for the CHJV were identified in assessments performed by the North American Bird Conservation Initiative. Several hundred species of birds depend on habitat in the CHJV during critical periods of their life cycles. Many breed or overwinter here, while others stop over during migration between breeding and wintering grounds. Some species are doing well, but populations of others are exhibiting long-term declines. Species with the greatest need of conservation attention typically suffer some combination of vulnerabilities, such as a relatively small range, a small overall species population, or a reliance on a habitat under threat.

  At 6 a.m., Heggemann and I were alone in the parking lot of the Mingo refuge visitor center until another car arrived and two birders popped out. Serendipity had brought us Mark Robbins and another expert birding colleague, who were doing a four-day bird survey of the state. I had first met Robbins, senior author of The Birds of Missouri, more than three decades earlier at an ornithological meeting in Philadelphia, and now Heggemann and I tagged along with these two top-gun birders. Robbins has a phenomenal ear and knowledge of songs, calls, and chip notes.

  Birding alongside local experts of a certain age is special for several reasons. Of course, they know the birds of the area, but over the years, they have also visited all the region’s nooks and crannies and divined the best spots for particular species, knowing when and where to look for each avian rarity. Moreover, they have lots of stories to tell. Heggemann and I knew we had stumbled upon an ornithological goldmine, and we mined this rich vein for all it was worth.

  With help from Robbins, we recorded lots of thrushes and vireos, and more than a dozen migrant warblers to boot. I was able to list quite a few passage migrants at Mingo: Chestnut-sided, Magnolia, Bay-breasted, Tennessee, and Black-throated Green Warbler, plus Northern Waterthrush. These six were headed north, mainly to Ontario—my northernmost destination. As the birds and I moved north, I heard more and more species in song, which aided their discovery. But I was finding that the passage migrants, although present, were scattered thinly throughout the abundant habitat. It was like an Easter egg hunt: I needed to look under every bush and in every treetop to find the quarry. Teale’s vaunted waves of migrants, of which I had dreamed, seemed no longer to exist.

  Among the warblers I tallied with Robbins was a new quest bird: the Yellow Warbler. This specialist of pasture edges and willow swamps is a commonplace open-country warbler that rivals the Common Yellowthroat in continental abundance. The male is olive-backed and rich yellow elsewhere, with an abundance of rusty orange streaks on its breast. The Yellow breeds from northern Georgia to Alaska and Labrador, winters from the Yucatán to northern South America, and is a species most birders come to take for granted because it is a vocal breeder just about everywhere. It is a true rural roadside warbler, its bright song heard while one drives down country roads. Mingo, with its marshlands and openings, is prime breeding habitat for this species, but it is surprising that I hadn’t recorded the bird earlier in my journey.

  SONGBIRDS’ INTERNAL GPS

  When a Neotropical songbird migrant such as the Yellow Warbler passes over the Gulf and up through the southern United States to a breeding ground like Mingo, it must rely upon a sort of biological global positioning system. Migrant songbirds, as we noted earlier, not only have a “compass” that helps them distinguish north from south; they also possess a map sense that helps them navigate to a precise location on the earth’s surface. With these two tools, the migrating bird can get where it wants to go.

  The migrant bird’s GPS system remains something of a mystery to scientists at this time. Yet we can understand some of its components, including its four central tools: magnetism, smell, low-frequency sound detection, and a bird’s powerful memory of places and routes. Experimental evidence suggests that birds may use the earth’s magnetism to detect their location on the globe, based on how the magnetic lines of force alter in declination based on distance from the equator. The closer one is to the North Pole, the more that magnetic lines of force trend toward horizontal. Nearer the equator, they are much declined due to the relative position of the North Pole and the spherical nature of the earth.

  Moreover, studies of homing pigeons, European Starlings, and swifts support the remarkable notion that birds employ their sense of smell to detect location. This idea is not so far-fetched—recall that migrating salmon return to their natal stream by detecting the unique scent of its water, even when they’re in the ocean. Some mammals’ sense of smell is also keen: witness the dogs trained to locate hidden drugs or land mines. Such a skill could be
very useful for adult birds returning to a breeding or wintering site.

  Birds also can detect infrasound—very low-frequency sounds—which they use to locate known topographic features that produce distinct sound signatures (such as wind striking mountain ranges or waves striking coastlines). Animals’ use of sound for navigation is probably more widespread than we know, mainly because humans lack this capacity. Think of the impact, for example, that the U.S. Navy’s underwater sound propagation experiments have had upon populations of whales and other cetaceans.

  Finally, older birds’ ability to remember places and earth features may allow them to retrace routes year after year, in the same way that we remember the details of places we visited in decades past. It is clear that learning is a major part of the map sense, for young birds are unable to make their way accurately to a specific site, whereas adult birds can do it with uncanny precision. Many field experiments have translocated birds hundreds or thousands of miles from their nests. The displaced birds were able to return with remarkable speed to their nests.

  Experiments have proven birds’ ability to take GPS-like actions, and we will speak more about these faculties when looking at research on thrush migration in a later chapter. In reality, however, there are still more questions than answers about birds’ internal GPS. It’s up to practicing research scientists to divine experimentally the finer details of the mechanism’s construction and operation, and probably many amazing discoveries will be unearthed by future researchers working on an array of bird species across the globe. At this point, we must simply recognize the awesome navigational capacities of migrating birds.