Sky Islands of Boreal Habitat

Bicknell's Thrush


Standing atop an Adirondack Mountain at dawn on a cold morning, the fog rises off a myriad of lakes, ponds, river, and brooks, filling the landscape below.

Mountain summits appear as islands jutting out from across a vast sea of fog. These “sky islands” are the breeding realm of many boreal bird species including the elusive Bicknell’s Thrush. For this bird, the world below that sea of fog does not exist.

High elevation boreal habitat includes mostly Balsam Fir, and a few Red Spruce, Paper Birch, and Mountain Ash trees, all on a carpet of moss. The higher you ascend, the more stunted the trees become until they completely disappear above the “tree line.” This alpine environment can be a harsh, windy, unforgiving place.

Yet, remarkably, this landscape is also filled with a diversity of animal and plant life.

Advantages of Birding on Whiteface Mountain

There are two ways to drive into high elevation boreal habitat in the northeastern United States, and Whiteface Veterans Memorial Highway is one of them. For birders and others, the ability to drive up into this fascinating world is a huge advantage since not everyone can take on the strenuous hike to the top. In 1935, when Governor (later President) Franklin D. Roosevelt dedicated the Whiteface Veterans Memorial Highway, he stated, “…for the millions of people who have not the facilities or the possibilities of walking up to the top of our great mountains, we have provided one mountain that they can go to on four wheels.” Constructing a highway up Whiteface Mountain was an amazing engineering feat in its day, and still seems remarkable even now.

Not only does the highway provide a way to drive up Whiteface Mountain, it also offers unique panoramic views of the thick Balsam Fir habitat above and below the road. On other high elevation mountains in the Adirondacks, a birder would be restricted to a narrow trail with thick habitat on both sides and very little chance of actually seeing birds. In 1939, George Wallace, after studying Bicknell’s Thrush on Mount Mansfield in Vermont, commented, “The discouragingly dense tangles in which Bicknell’s Thrushes dwell have kept their habits long wrapped in mystery…Only a freak ornithologist would think of leaving the trails for more than a few feet.” Having bushwhacked in high elevation habitat, I have the shredded clothes to support that statement.

Whiteface Mountain is New York’s fifth highest peak, so there is a lot of high elevation boreal habitat on the upper reaches of the mountain, with a substantial Bicknell’s Thrush population as a result. The number of birds increases a birder’s chance of actually seeing and hearing one.

Last, but not least, the spectacular views from Whiteface Mountain’s summit are unparalleled.


Our Only Endemic Species

Bicknell's Thrush

Bicknell’s Thrush is the species that draws birders to the mountain tops across New York, Vermont, New Hampshire, Maine, and a few nearby locations in Canada. It is by far the number one species that visiting birders to the Adirondacks want to see during the breeding season. Birders come from across the U.S., Canada, and beyond just to see this bird. For people who keep lists of the birds they have observed in North America, it is usually one of the last species added.

In 1995, Bicknell’s Thrush was recognized as a distinct species from the Gray-cheeked Thrush, which breeds much farther north. It was named after Eugene Bicknell, an ornithologist who studied the bird in the Catskill Mountains a century earlier in 1881.

Bicknell’s Thrush is a neotropical migrant and winters in the Dominican Republic, Puerto Rico and Cuba. It is the only endemic species in the northeastern U.S. (meaning it is native and limited to just this part of the country), and has one of the most restricted breeding and wintering ranges of any North American bird.

Bicknell’s Thrush practices an unusual mating system called polygynandry where males and females mate with multiple individuals. Each nest has young from different males, and males may have young in several nests. Males also feed young in multiple nests, including nests where they do not have any young.

The beautiful flute like song of Bicknell’s Thrush is ethereal. For me, it is intertwined with the experience of being high on an Adirondack mountain. They are most vocal pre-dawn, dawn, and evenings – singing well beyond dusk. While much of their time is spent hidden in the thick Balsam Fir habitat, males will fly up to the top of an exposed, dead snag for a singing perch.

Dawn and dusk are also when Bicknell’s Thrush is most active. Birds fly back and forth across the highway on Whiteface interacting with one another. They can also be spotted walking on the ground at the edge of the highway or perching on one of the rock walls.

Birders focus their efforts to see Bicknell’s Thrush in an area just below the “Lake Placid” hair-pin turn to the very summit of Whiteface Mountain. Bicknell’s Thrush favors small openings in the Balsam Fir habitat, such as the rock slides down the mountain and the edge of the highway.


Other Birds on Whiteface Mountain

In addition to Bicknell’s Thrush, Blackpoll Warbler is another species that is strictly found in higher elevation habitat – usually above 2,600 feet. This bird, with a quiet, insect sounding song, is a champion migrant! In the fall, Blackpoll Warblers breeding across northern North America head east. They launch from northeastern North America migrating over the ocean directly to South America – a 4-day, non-stop journey for a bird that weighs under half an ounce!

As a result of a warming climate, other bird species are expanding their breeding ranges upward in elevation. Cold springs used to restrict Swainson’s Thrush from the highest reaches of the mountains. Now, they can be found all the way to the summit on Whiteface, along with American Robins, which have also shifted their breeding range higher in elevation. For Bicknell’s Thrush, already at the summit, there is nowhere left to expand.

Many other birds can be found nesting on Whiteface Mountain’s upper reaches: Black-backed Woodpecker, Yellow-bellied Flycatcher, Black-capped and Boreal Chickadees, Red-breasted Nuthatch, Winter Wren, Ruby-crowned Kinglet, Nashville, Yellow-rumped, and Black-throated Green Warblers, White-throated Sparrow, and Dark-eyed Junco.

Other species can be observed at high elevation on Whiteface: Merlin, Peregrine Falcon, Common Raven, Red and White-winged Crossbills, and Pine Siskin.

It may seem surprising, given the harsh climate at high elevation, but quite a few mammal species can also be found high on Whiteface Mountain: Red Squirrel (the largest predator of Bicknell’s Thrush nests), Snowshoe Hare, Porcupine, Pine Marten, and Woodchuck.


Threats of Bicknell’s Thrush

The Vermont Center for Ecostudies began the Mountain Birdwatch project in 2000 to monitor Bicknell’s Thrush and other high elevation species. Surveys are conducted in June each year across the four states of New York, Vermont, New Hampshire, and Maine beginning at 4:30 a.m. – so volunteers either climb through the night, or camp near the summits.

Listed in New York as a species of “Special Concern,” Bicknell’s Thrush faces a myriad of threats and its population is declining. Climate change, with its effects on forest composition, pests, diseases, natural disasters, increased interspecific competition, and changing migratory patterns, is a huge threat to Bicknell’s Thrush. Others include: acid deposition, logging, predation, and habitat loss. On the species winter grounds, much of their broadleaf mountain habitat has been lost to agriculture, cattle ranching, forest fires, and human settlement.

In 2010, the Center for Biological Diversity petitioned the U.S. Fish and Wildlife Service requesting that Bicknell’s Thrush be listed as threatened or endangered under the Endangered Species Act of 1973. A decision on the listing will be made in late 2017. Typically, a listing puts actions in place to help a species recover, such as the success story for the Bald Eagle, but the primary problem for Bicknell’s Thrush is too much carbon in the atmosphere resulting in a warming climate – certainly not an easy “fix.”


Dawn on Whiteface

Several years ago, after reading a news story about Aaron Kellett, the new Whiteface Mountain Manager at the time, mentioning that he was looking for people thinking outside the box, I gave him a call. We discussed the possibility of driving birders up the mountain at dawn before the road opens to see Bicknell’s Thrush and other high elevation birds. He thought it was a great idea and now a few NYS licensed guides can drive birders into Bicknell’s Thrush habitat when the birds are most vocal and active, and when the mountain is quiet with no other vehicle traffic.

People now travel to the Adirondacks from all over the U.S. and Canada to see and hear Bicknell’s Thrush. Sometimes, we are fortunate and see the bird right away and sometimes we work for hours before a view. At times, the bird is singing on an open perch with lovely views, other times it is a silhouette in the fog, or we are on our hands and knees peering into the dark understory of the Balsam Fir at a bird perched just above or on the ground. However, the bird is viewed, it is always memorable and exciting, and often emotional, for a person to see this elusive species for the first time.

A couple years ago, a woman from Pennsylvania brought her elderly father, who was in his 80’s, to the Adirondacks. I found a singing Bicknell’s Thrush on a perch over the wall near the Castle building. Her father viewed the bird through my scope and was thrilled. Later, she whispered to me that it was his last chance to see that species – a bittersweet moment.