North on the Wing

by Bruce M. Beehler

  Cooper and his team shared a rented house in rural Luzerne, and I put my tent under a tree in their front yard. I then took the research group out for dinner at a nearby watering hole named Ma Deeters. We ate big burgers and drank cold beer in a big, noisy, wood-paneled room and talked research and birds, exactly what ornithologists like to do on a Friday evening in June.

  While camped in Ontario, I had searched eBird online for late-spring sightings of Cape May Warblers—one species that had, to date, eluded me. I found one recent record of the species from Luzerne. Remarkably, that eBird record had been uploaded by one of Cooper’s assistants, Ethan Gyllenhaal. Gyllenhaal had located several singing male Cape Mays on territory in conifers at Cooper’s rental house as well as at the nearby Luzerne Boardwalk. The Cape May Warbler was a species that had remained just out of reach throughout my trip, yet here it was, singing in Cooper’s front yard, at the very southern limit of its breeding range. I had journeyed here to spend time with the very rare and restricted Kirtland’s Warbler but now found that the ever-elusive Cape May was thrown in as an unexpected bonus. In my tent by 10 p.m., I drowsed to the sound of a drumming Ruffed Grouse and dreamed of the two rare warblers that awaited me in nearby habitat.

  On the next morning, Saturday, June 27, the field crew planned to head out as usual, because they worked seven days a week. I awoke at 4:45 a.m. to a singing Whip-poor-will and, after a quick breakfast, headed out with Cooper and David Bryden (an assistant from New Zealand) to a nearby Kirtland’s study site. Along the way, Bryden told me he had visited my most recent field project in New Guinea. Ornithology is a small world, and field assistants and volunteers travel the world in search of interesting research opportunities.

  Cooper told me that the Kirtland’s Warbler population now stood at two thousand pairs—up from a low of just two hundred pairs in the late 1980s. The species’ breeding habitat is essentially confined to a ninety-mile-diameter polygon of sandy outwash plain in the northern portion of the Lower Peninsula of Michigan, centered on the community of Grayling. Here I was back in postglacial Jack Pine habitat. The warblers set up territory only in very young Jack Pine monocultures, where the trees stand five to twelve feet tall. The birds nest on the ground in the shade of a pine, hidden in low, thick mats of blueberry. The males arrive on territory in early May, and the first nests are completed in late May. Nestlings typically leave the nest in late June.

  This morning, we encountered at least six warblers, but because of the lateness of the season, the females sat quietly on the young and the males did not vocalize much, making them more difficult to track down. I followed Cooper and Bryden around plot DNR-2 as they checked the status of nests that had been located earlier in the season. This patch of habitat, DNR-2, had been created solely and specifically for Kirtland’s Warblers by conservation teams from the state, and its trees were seven years old.

  Each Kirtland’s nesting patch is manufactured by conservationists. First, the area is clear-felled, the trees and tree waste are removed, and the bare field is disked; pine seedlings that are grown in a nursery are hand-planted in rows in the cleared area, with an intertree distance of about nine feet. Herbicide is applied regularly during the growing season to keep down competing vegetation and to allow the pines to prosper. Once the trees reach a height of five feet, territorial male warblers begin to settle in the pine stand. At this stage, conservationists set and bait large wire traps in small clearings among the pines to capture and remove all visiting Brown-headed Cowbirds. Each site is closed to all visitors to allow the warblers to breed in peace. As of 2015, the state had twenty-three Kirtland’s Warbler management areas, totaling 127,000 acres. Because each site outgrows its usefulness to the species in about seven years, the agency that owns the land needs to create new sites every year to make up for those that have outgrown the warblers. An additional several thousand new acres of breeding habitat are created each year.

  Kirtland’s Warbler is thus, like the Red-cockaded Woodpecker, a conservation-dependent species—one whose survival on earth depends on active annual intervention by humankind. For reasons unknown to us, the millions of acres of fire-prone Jack Pine monoculture that I found in northern Ontario are ignored by this rare warbler. There are plenty of fresh tracts of Jack Pine in Canada, but they remain empty of Kirtland’s.

  Kirtland’s Warbler is also a poster child for the need for full life-cycle conservation. The term describes the need to take conservation action in all sectors of the species’ year-round range to ensure its survival. Thus conservation scientists today are working to provide suitable protected habitat for Kirtland’s Warbler in its restricted wintering range in the Bahamas, in its stopover sites in the southeastern United States, and, of course, on its breeding habitat in Michigan. In fact, full life-cycle conservation is a practice that would benefit scores of migratory songbirds, not just Kirtland’s Warbler.

  The Kirtland’s breeding habitat is a bit off-putting to a first-time visitor. It has the look of a young Christmas tree farm, with trees planted in a geometric grid at a density of about 1,100 trees per acre (allowing for the presence of several openings within these plantings), something of a monotonous affront to those who love the randomness of nature. But Kirtland’s Warblers appreciate these monoculture plots, so they are what conservationists give the birds. I found few other birds using the manufactured habitat: Hermit Thrush, Blue Jay, Common Raven, and Field Sparrow. Clearly, this is no avian hotspot, just a specialized nesting habitat for a very specialized bird.

  Cooper’s study included work on the Brown-headed Cowbird, which tricks other species into raising its offspring. The female cowbird mates and then lays its fertilized eggs into the fresh nests of a variety of songbirds, include Kirtland’s Warbler. This trickery substantially reduces the nesting success of the species that receives the egg donation from the cowbird. The doting and naive parents end up preferentially provisioning the fast-growing and aggressively demanding cowbird nestling. The combination of the shortage of suitable Kirtland’s nesting habitat, plus the drag of cowbird nest parasitism, had long kept Kirtland’s numbers perilously low. The government recovery team, tasked with bringing the warbler back from the brink of extinction, has perfected a cowbird-trapping procedure that has massively reduced the incidence of nest parasitism of Kirtland’s Warbler. This spring, Cooper’s team located 150 warbler nests, and only one had a cowbird egg in it. After decades of summer trapping and removal, cowbird populations are now so low in central Michigan that they no longer pose an active threat to warbler nesting.

  THE CAPE MAY WARBLER AND THE SPRUCE BUDWORM

  After the visit to DNR-2, I joined the team of assistants on a quick tour of the Luzerne Boardwalk, a local birding hotspot that is the site of a boreal cedar swamp situated within Huron National Forest. Within minutes of our arrival at the head of the boardwalk, we found a male Cape May Warbler singing on territory. Marked with chestnut cheeks, a rich yellow breast with abundant black streaking, and a dark crown, the male was collecting spruce budworm pupae and taking them to a nest high in a conifer to feed a nestling. A Lincoln’s Sparrow sang from an adjacent field, as did a Black-billed Cuckoo and Magnolia, Nashville, Pine, and Palm Warblers, as well as several Ovenbirds. Driving back to Cooper’s house, we saw a Coyote crossing the road. White-tailed Deer abound here—and fawns are prime food for Coyotes.

  On Sunday, a White-breasted Nuthatch awoke me by calling outside the tent in the 39°F air. I headed to the Luzerne Boardwalk on my own, where the Black-billed Cuckoo was calling like crazy—was the cuckoo, a caterpillar specialist, celebrating the budworm outbreak? Nashville Warbler and Ovenbird were in song, as well as Rose-breasted Grosbeak and Lincoln’s Sparrow. I had come to the boardwalk, however, mainly to spend more time with the nesting Cape May Warblers. Once again a male was collecting spruce budworms and carrying them up to its hidden nest. The foraging male was very confiding—at one point he perched down on the sandy walking path, chasing a writhing budworm pupa on foot as I
stood eight feet from him. To East Coast birders, finding this species in breeding plumage in spring is a major challenge. The males are strangely beautiful, with their chestnut cheek and big white wing-bar. Males in spring migration on the East Coast mainly lurk high in towering Norway Spruces, their thin and high-pitched song easily missed. Thus it is a treat to see one of these gorgeous birds at close range and below eye level.

  The Cape May Warbler is a spruce budworm specialist, and its populations, as well as those of the Bay-breasted Warbler, rise and fall with the abundance of the budworms, which they both eat and feed to nestlings. Because spruce budworm infestations are cyclical, coming and going in the boreal spruce-fir forest, Cape May Warbler populations follow a similar pattern. A small, nondescript moth in the family Tortricidae, the spruce budworm lays its eggs on the needles of spruce and fir. The larvae burrow into the needles and feed on them. Budworm infestations can kill a mature Balsam Fir, though spruce typically survive the attack. A single budworm cycle can last as long as two decades, populations building over years to a peak followed by a crash. The Luzerne area’s spruce and fir were suffering the early stages of a budworm outbreak; I saw big red-brown patches of budworm-invaded needles on some Balsam Firs.

  Midmorning, I headed out with the team to a second Kirtland’s Warbler breeding site to spend more time with this second marvelous warbler. Yes, its breeding habitat is unprepossessing, but the bird itself is easy to love. The male sings a loud and chattery song from atop one of the myriad low pines. It is a glory to see him throw back his head, open his beak, and let his voice soar. The species is remarkably unwary; both males and females seem entirely unfazed by the presence of human observers. Thus birdwatchers fortunate enough to gain permission to walk in the habitat can share some intimacy with the birds as they go about their daily lives, and that is special for such a rare species; one can stand among head-high pines while the adorable little birds move about at eye level. I followed a Kirtland’s pair for about twenty minutes, making a spishing sound to attract them, and in most instances the female approached within a few feet of me. Their plumage is classic for a wood warbler: mainly gray above and pale yellow below, with dorsal and ventral black streaking, plus a broken white eye-ring, thin white wing-bars, and prominent white undertail coverts. The eye-ring, set against the dark face, is particularly fetching. In many ways this is the prototypical wood warbler, yet strangely it is rare. When will it discover the vast Jack Pine stands of northern Ontario?

  At some point in their lives, many birders decide to make the pilgrimage to Michigan to see the Kirtland’s. Hundreds visit every spring. The warbler recovery team has established a protocol for visitors: they meet in Grayling or Mio, caravan to a breeding site, and carefully tour in groups led by a local volunteer to experience the bird and learn about the whole process of conserving the species, which includes the story of the cowbird. This is all very sensible and prudent, but, that said, something about seeing the species under such hothouse conditions detracts from the joy and independence of the birding experience.

  One can avoid such an enforced group experience by seeing a Kirtland’s on migration. Magee Marsh, Ohio, on the south shore of Lake Erie, is a particularly good stopover site to spot the species on its journey. In 2014, a year before this trip, I’d pulled into the Magee Marsh parking lot at about 6 p.m., after driving nine hours from home. A clot of photographers were hanging out, their tripods in a cluster in the grass beside the parked cars. I sauntered over to ask what was up. A Kirtland’s Warbler was hanging out on East Beach. By this time, most of the day’s visitors had returned to their motels after a long day of birding, but I drove to the East Beach parking lot and to search for what I thought might be a needle in a haystack.

  To my surprise, I did not even need to locate the bird. I needed only to locate the remnant clusters of birders—a semicircle of five people in the low beach vegetation—communing with the Kirtland’s as the sun dipped low. One turned to me and silently pointed to a piece of driftwood in the sand where a male Kirtland’s perched, tail wagging diagnostically. I spent more than an hour on the beach as the bird foraged on the sand and in the vegetation, never straying more than ten feet from where I’d first seen him. Before long, I was the only person left with the bird. Ignoring my presence, he was intent on hunting down a type of small fly, abundant on the beach at that time.

  HARTWICK PINES

  Midday on Sunday, I break down my tent and head north to resume my Canadian adventure. Cooper’s crew advises me to stop at Hartwick Pines State Park, just north of Grayling, before crossing the border. The park features a forty-nine-acre tract of old-growth forest and an adjacent museum dedicated to the history of the logging of Michigan’s great virgin forests.

  The park’s circuit walk through the old-growth forest was more than worth the price of admission. It was a stand of White Pine, Red Pine, Eastern Hemlock, Sugar Maple, and American Beech, averaging 350 years old and situated on flat ground. The tall canopy was thick and complete, and there was surprisingly little undergrowth in the deep shade cast by the great trees. It was quiet and peaceful, with strains of birdsong adding to the cathedral-like experience. The families walking the trail spoke in low tones, respectful of the ancient forest. Of course, the familiar Red-eyed Vireos sang from the deciduous edge of the old growth. Maples dominated the deciduous trees, with sapling American Beeches filling in the understory and a few mature beeches scattered through the tract. I heard Black-throated Green Warbler, Rose-breasted Grosbeak, Eastern Wood Pewee, and Pine Warbler. Off in the distance was the drum of the Pileated Woodpecker. Wouldn’t it be great, I wondered, if this ancient forest encompassed 490 or 4,900 acres rather than just 49?

  The museum told not only the logging story but those of its victims: wild nature and the poorly paid loggers who brought down the great timber. It was both riveting and depressing to examine closely the crisp black-and-white prints of the old logging scenes, accompanied by text enumerating the wholesale pillaging of this seemingly limitless resource by rapacious timber barons. These men cared not a whit for the proper treatment of their employees or the proper management of the vast natural resource that made them immensely wealthy. That first harvest of more than 19.5 million acres of virgin timber, none replanted by the greedy plunderers, permanently impoverished the upland forests of Michigan. Generating more than a billion board-feet of timber a year during the peak of operation, around 1890, the lumber produced more wealth than the California Gold Rush.

  White Pine was the tree that made men rich, and most timber operations targeted it in particular. Only later, when the White Pine was gone, did other species gain in importance as marketable timber. The ancient forests that the loggers found when first cruising the wilds of northern Michigan were rich in conifers: not only the White Pine but also Red Pine, Eastern Hemlock, and White Spruce. Today these lands are dominated by maple, birch, and beech. The ecological and economic differences between the ancient mixed conifer forests and today’s deciduous forests are considerable. The impacts this forest destruction has had on the wildlife and overall biodiversity of the state have been measureless.

  Black-throated Green Warbler

  Given the breathtaking avarice of the timber barons, it is a miracle that the remnant forty-nine acres at Hartwick Pines were never cut. The objective of the timber companies was to harvest every merchantable tree. Today, the most productive forest lands in Michigan have been cut over three times, and true old-growth forest lurks in only a few protected areas. The best are in the Upper Peninsula: the thirty-one-thousand-acre Porcupine Wilderness State Park and the eighteen-thousand-acre Sylvania Wilderness of Ottawa National Forest. Both large old-growth tracts lie a few hours east of where I camped in northern Wisconsin, but, sadly, I had not known of their existence when I passed through the area.

  BACK NORTH

  After the bittersweet experience of Hartwick Pines, I head north on Interstate 75 toward the Trans-Canada Highway and Chutes Provincial Park, in
Massey, eastern Ontario, 150 miles east of Sault Sainte Marie. It is a stunning late-spring Sunday afternoon. I stop for lunch on the northern side of the Mackinac Bridge, at Saint Ignace—a lovely tourist destination with unrestricted views of the water. It has the look of a beach town, tailored to summer tourists, a bit like Newburyport, Massachusetts, but without the seafaring history. I dine alfresco as a light breeze comes off the straits. All around me families with children celebrate their weekend amid the vacation vibe of this small shore town on a day of wondrous weather. On any given day, it could just as well be 58°F here, with rain and twenty-mile-an-hour winds off the straits. We are all thankful for the meteorological bounty that has come our way.

  Along much of the Trans-Canada Highway, I had scenic watery views over the North Channel, a large embayment of Lake Huron. The lake’s north shore has a north-country look, with a mix of aspens, birches, spruce, fir, and Tamarack. An Osprey carrying a large fish passed over the car, followed by a Great Blue Heron. This shoreline is very much defined by its islands and peninsulas. For the first time on the trip, I saw a Banded (or White) Admiral, a butterfly I’d looked for since I reached Wisconsin. I’d seen not a one in northern Ontario, which remains a mystery.

  Chutes Provincial Park is small—just 270 acres—but it contains the falls and rapids of the River aux Sables, and there are good hiking trails in its woods. After the long drive from Michigan, I was pleased to sleep in the next morning. An Ovenbird sang loudly beside my tent early, but I rolled over. It was good sleeping weather: the 8 a.m. temperature was 58°F. A four-mile hike on the Twin Bridges Trail began my day, and I found, in the middle of the trail, the severed back half of a Least Weasel (which proved to be the only weasel I encountered on my journey). I guessed the front half had been consumed by an owl, which had dropped the back half by some mishap.