Biology Reference
In-Depth Information
forest fires, but the suppression of fire was surely a contributing factor to the Kirtland's nose-
dive.
Visiting the breeding grounds during the Kirtland's spring pilgrimage is permitted only in the
mornings, so birders must seek afternoon diversions elsewhere. The nearby Au Sable (pro-
nounced
O
-sible) River offers fine canoeing and top-rated fly-fishing. For searchers of rarity,
there is another one-of-a-kind, must-see site that in its own way deserves equal billing with
the Kirtland's: about thirteen kilometers northeast of Grayling lies Hartwick Pines State Park,
home to the largest remaining stands of 350-year-old eastern white pine and eastern hemlock
in North America. And what could be a better ecological complement to a 5-year-old jack
pine grove than a forest of centuries-old conifers? My curiosity got the better of me because
some biologists speculate that in rare habitats one should naturally find rare species. What
treasures did Hartwick Pines hold?
The walkway to the park was full of singing male rose-breasted grosbeaks, perhaps rival-
ing the scarlet tanager and the painted bunting as the most beautiful songbird in North Amer-
ica. Feeders at the reserve headquarters pulled in evening grosbeaks by the dozen. A true
deep-forest birding adventure awaited those who, like me, had never set foot in an old-growth
white pine forest.
Nature writers have compared the feel of wandering into an old-growth stand to that of
entering a cathedral. In the park, towering trees of massive girth created a cool environment.
The understory layer was empty, as the dense shade prevented much of a shrub layer. The
eastern hemlock was once called the “redwood of the east” because it can grow more than
50 meters tall and have a trunk 2 meters in diameter. In Great Smoky Mountains National
Park, some 500-year-old trees still survive, but hemlocks elsewhere are not found in the large
numbers they once were. Back in the 1920s, a bug from Japan known as the hemlock woolly
adelgid appeared in New England and the mid-Atlantic states and began feeding on hemlocks
of all sizes. Within eight years after infestation begins, a tree can die. Some ecologists say
that the diminution of this widespread and once common hemlock may have had greater sec-
ondary effects than the loss of the American chestnut in the 1930s. Hemlocks play a vital role
as habitat for species ranging from beetles to trout by providing deep shade along streams
and cool refuges in the forest. Remove the hemlocks and the bright sun drives away the shade
seekers.
Along the route I heard other warblers singing: pine, blackthroated blue, and black-
throated green. The ethereal songs of the wood thrush and hermit thrush made me stop and
lie down under a grove of ancient trees to take it all in and reflect on what I had learned so
far. I had filled pages of notes, but the lode of natural history insights danced around answers
