It’s 4:30 a.m. on an early June day just outside Albany, New York. Rush hour, with its impatient drivers and honking horns, has yet to begin. Just before sunup, the only headlights are those of biologists driving to a meet-up in the Albany Pine Bush Preserve’s main parking lot. They will soon head into the Pine Bush, as it’s locally known, to catch and band Indigo Buntings, Prairie Warblers, and other birds that breed in this pitch pine-scrub oak habitat.
The Pine Bush Preserve, which lies in the midst of crisscrossing highways, suburban neighborhoods, industrial parks, and Amtrak railroad tracks, is, however improbably, one of the largest of 20 inland pine barrens left in the world and, scientists say, may be the best remaining example of the ecosystem. In 2014, the Albany Pine Bush Preserve was designated a U.S. National Natural Landmark.
It’s also an Important Bird Area, supporting an assemblage of species that prefer young forests and shrublands. No fewer than 78 Species of Greatest Conservation Need, as designated by New York state, dwell in the Pine Bush, of which 45 are birds. Among them: Prairie Warbler, Scarlet Tanager, Ruffed Grouse, Blue-winged Warbler, and American Woodcock. In addition, Golden-winged Warbler, Red-headed Woodpecker, and 17 other birds found in the Pine Bush are on New York’s list of High Priority Species of Greatest Conservation Need.
Many of them, such as Common Yellowthroat, Eastern Towhee, and Prairie Warbler, are common in the Pine Bush, despite being in decline elsewhere in the region, writes Neil Gifford, conservation director at the preserve, in a paper in Landscape and Urban Planning. “Inland pine barrens offer the rarest type of shrubland habitat in the northeastern United States and may contribute disproportionately to the regional diversity and conservation of shrubland birds.”
The once and future Pine Bush
The Pine Bush was formed more than 10,000 years ago. As the Wisconsin glacier melted and retreated from the region around 20,000 years ago, a sand delta formed in Glacial Lake Albany, according to Natural History of the Albany Pine Bush by Jeffrey Barnes. Lake Albany extended north 50 miles from today’s city of Albany to Glens Falls, New York.
About 12,000 years ago, the lake drained, leaving the delta sands exposed to wind and rain. Parabolic dunes formed and still exist in the Pine Bush. “The remains of the ancient Pine Bush sand delta cover approximately 40 square miles,” writes Barnes. Atop the sands lie pitch pine and scrub oak, the dominant Pine Bush plant community type. “This is the rarest of all community types in the Albany Pine Bush ecosystem,” Barnes notes. “The pitch pine-scrub oak barrens occurs on well-drained, acidic, nutrient-poor soils among the sand dunes.”
Development on all sides of the Pine Bush is ever-encroaching, however, from small businesses like auto-repair shops to spillover industrial parks on the perimeter of a nearby mall.
Saved by a tiny butterfly
Designation of the Albany Pine Bush as a preserve almost didn’t happen. A tiny endangered butterfly named the Karner blue, which makes its home there, saved the day. The butterfly’s name derives from Karner, New York, the hamlet where it was discovered. Karner’s pine barrens are now protected within the boundaries of the preserve.
“The disappearance of the Karner blue was a symptom of the declining health of Northeast pitch pine-scrub oak barrens like the Pine Bush,” says Gifford, “especially the wild lupine that flourishes in this habitat.” Wild lupine is the only food of the Karner blue’s caterpillar; the plant’s decline was almost certainly the reason for the plight of the butterfly. The Karner blue was instrumental in rescuing the Pine Bush, Gifford says, preserving it for countless species, including dozens of birds.
Novelist and lepidopterist Vladimir Nabokov of the Harvard University Museum of Comparative Zoology described the butterfly in 1943, based on a male Pine Bush specimen. His novel Pnin, published in 1957, compares the butterflies to “blue snowflakes.” Karner blues once swarmed by the millions in the Albany region, but that multitude is long gone. “This tiny blue insect could easily have slipped unnoticed into extinction,” Barnes writes, “but it managed to capture the imagination of environmentalists and is now a symbol of endangered species, taking rank with the likes of the wolf and the Peregrine Falcon.”
The threat of the Karner blue’s extinction, says Gifford, “mobilized grassroots environmental activists. Conservation organizations, especially The Nature Conservancy, successfully worked with local and state government officials to protect the area.” In 1988, New York Environmental Conservation Law Article 46 created the Albany Pine Bush Preserve.
The initial protected area was just a few hundred acres but today has grown to more than 3,300 acres. “Efforts to restore the barrens and the Karner blue, now recovered locally, have been a tremendous help to conserving declining shrubland birds,” says Gifford.
Birds that breed in the Pine Bush, like American Woodcock, Prairie Warbler, Eastern Towhee, Brown Thrasher, Eastern Whip-poor-will, and Indigo Bunting, are all riding on the backs, as it were, of diminutive Karner blues. The butterflies’ wingspans are just 1.3 inches.
The need for lupine
Wild lupine, the only native lupine in New York state, ranges from the Gulf of Mexico up the Atlantic coast to southern Maine and westward to the southern Great Lakes region. It thrives only in sandy soils in dry, open areas “where competition and shade are reduced by recent burns or other catastrophic events,” writes Barnes.
In the Albany Pine Bush, wild lupine blooms in open pitch pine-scrub oak. Over the past 15 to 20 years, however, the number and size of lupine patches have declined to one-tenth of what they were. Fire suppression and land development are likely to blame, researchers believe. Gifford points to a valley where lupine flowers cover the hillsides. “We did a controlled burn here earlier this spring, and, in a short time, look at how the plants have regrown,” he says. Lupines dot the landscape as far as the eye can see. That’s good news for the Pine Bush’s butterflies, especially its endangered Karner blues.
Habitat loss from development in the Pine Bush is on a par with habitat destruction due to a lack of fires, says Gifford. “The area needs fire to maintain its open plant communities,” he says. “Fire prevents the succession of vegetation that would otherwise lead to a closed forest.”
Over centuries, the Pine Bush has likely experienced natural fires at regular intervals, perhaps every six to 15 years. Historically, the Pine Bush probably burned during hot, dry weather or droughts. But fire isn’t a welcome neighbor in an area that’s now chock-full of homes and businesses. To counter a recent history of fire suppression, Pine Bush crews now use controlled burns to maintain the pitch pine-scrub oak barrens. “In the absence of periodic fire,” writes Barnes, “the pine barrens ecosystem of the Albany Pine Bush would disappear.”
In the East, the opening of the forest canopy by agriculture, logging, and burning converted millions of acres into potential habitat for birds like Indigo Buntings, states Arthur Cleveland Bent in Life Histories of North American Cardinals, Grosbeaks, Buntings, Towhees, Finches, Sparrows, and Allies. Bent quotes a source as stating, “Perhaps originally a bird of successional vegetation in the eastern deciduous forest of North America and of oak openings along the prairie-forest ecotone, the Indigo Bunting was undoubtedly restricted in numbers by the relatively closed canopy of the climax forest.” The same could be said of many of the Pine Bush’s birds. For buntings, Prairie Warblers, and other species of the barrens, the open scrub-shrub is paradise.
Into the Pine Bush
Sunup is just minutes away, so the ornithologists drive from the main Albany Pine Bush Preserve parking lot to a smaller one at the trailhead of the Kings Highway Barrens, where a loop trail runs for a little more than 2 miles. Houses line one side of the road; the other side is wild Pine Bush. Dawn soon rises over the barrens, taking with it the last of an early morning fog. Bird song fills the air.
Gifford and crew lug heavy packs and boxes down a sandy trail that runs atop an ancient dune: poles for stringing mist nets, along with the nets themselves; bird-banding supplies; and a screened tent to work in. They set up camp in a shady swale, then move out into the scrub-shrub to erect the nets in a dozen likely spots. Mere feet from camp, a bluebird family has taken up residence in a dead snag, the female flitting to and from the nest hole with the avian version of breakfast. A Scarlet Tanager watches the proceedings from a branch just above the biologists’ tent.
Net-checks are run all morning, on the hour. The researchers return with buntings, warblers, goldfinches, and cuckoos to weigh and band. The Pine Bush breeding season banding project began in 2012. A similar fall effort started five years earlier; results to date indicate that the preserve is an important autumn migration stopover point for Nashville, Palm, Magnolia, and Blackpoll Warblers, Lincoln’s Sparrow, and Ruby-crowned Kinglet. The results were reported in The Wilson Journal of Ornithology.
In the summer 2019 banding season, which ended on August 6, the biologists caught a total of 636 birds of 58 species. Top birds included 131 Gray Catbirds, 121 American Robins, 70 Baltimore Orioles, 55 Prairie Warblers, 47 Field Sparrows, 36 Common Yellowthroats, 26 Orchard Orioles, 23 Black-capped Chickadees, 18 House Wrens, 16 Chestnut-sided Warblers, and eight Indigo Buntings.
One of the more high-interest birds of the Pine Bush, Prairie Warbler, plays an especially important role ecologically. “The warbler’s narrow habitat requirements restrict it not to prairie,” writes Barnes, “but to open dune formations where pitch pines are few and scrub oaks and dwarf chestnut oaks dominate the landscape.” Prairie Warblers, adds Gifford, “are one of the best gauges of inland pitch pine-scrub oak health.” In the journal Landscape and Urban Planning, he and colleagues report that “the clearest evidence of shrubland specialization and therefore indicator value is found in the Brown Thrasher, Field Sparrow, and Prairie Warbler.”
Of 13 Prairie Warbler nests the researchers located in one summer, 53.8 percent successfully fledged young. “Despite the fact that barrens burn often,” Gifford says, “they represent very stable breeding season habitats for this species.” Albany Pine Bush biologists are working with colleagues at the University of Massachusetts-Amherst and the U.S. Forest Service to learn more about non-breeding season Prairie Warblers. Preliminary data from birds equipped with lightweight tracking devices called geolocators indicate that birds breeding in the Pine Bush winter on the Caribbean island of Hispaniola. The scientists hope to answer the question of whether overwintering habitat affects the warblers’ breeding success.
Bunting in blue
It’s now well past noon. Nets are packed up, and most team members return to the office or home. A splinter group, however, heads down another part of the trail and into an open field, where a bunting’s sweet song soon greets them.
Four pairs of binoculars go up, and field ecologist and environmental educator Amanda Dillon spots a flash of blue atop a pine. “If we wait a while,” she says, “the bunting will probably fly around the field, especially if another male starts singing.”
As if on cue, a second male announces his presence. The first male lifts off his perch and zips around, almost swallow-like, looking for the intruder. No luck. Finally, with the second male nowhere in sight, he returns to the same branch high in the pine. From there, he has a view over the Pine Bush, with its rolling sand dunes long ago hidden beneath shrub-scrub, and its bursting-with-blue fields of lupines and Karner blues.
The scientists turn to leave, retracing the steps to their cars. As they pull onto the road, the Pine Bush soon fades, a tangle of afternoon traffic taking its place. In their wake, the birds’ musical notes mark not only Pine Bush nesting territories but also an entire ecosystem.
An outdoor concert series
Like any well-established park or nature reserve, the Albany Pine Bush Preserve is awash in bird song in spring and summer. Two of its iconic singers are Indigo Bunting and Prairie Warbler.
The buntings are summer residents of the Pine Bush, where, like other birds that breed here, they can easily find dense cover for nesting and tall trees for song perches. Although the males’ bright blue plumage is conspicuous, it’s their songs that help biologists locate them.
“This song has a characteristic shared by no other,” wrote Arthur Cleveland Bent. “There is a whole-souled concentration about it. The bird, when he sings, sings just as well as he can, and I believe as loud as he can — he gives himself up entirely to singing and throws the notes out for all he is worth.” Scientists conducting a study in the 1930s found that for the months of June and July, one Indigo Bunting sang 4,320 songs a day, a grand total of 263,520 songs in 61 days.
The buntings learn their songs during their first breeding seasons in social interactions with other buntings, says environmental educator Amanda Dillon. Neighboring males share their tunes in local dialects, or “song neighborhoods.” These distinct themes may last as long as 20 years (10 or so bunting generations). The themes are modified when new singers from generation to generation add new twists.
Not to be out-sung are Prairie Warblers, whose songs fall into two categories, Type A and Type B. Type A songs are ascending buzzy notes. B songs are whistled notes. When males first arrive on breeding grounds, A songs are sung throughout the day. Once males are paired, they switch to B songs at dawn, then add in A songs for the rest of the day. A songs are typically sung near females and near nests. B songs are used when interacting or fighting with other males and near the borders of territories.
“All summer,” says Dillon, “there’s a Pine Bush avian outdoor concert series happening.”
This article was published in the May/June 2020 issue of BirdWatching magazine.