Geoscience Reference
In-Depth Information
also responsible for the dispersal of seeds and the perpetuation of some species of shrubs and trees, such as the
flowering dogwood and oaks.
The diverse mixture of hardwoods and conifers supports around 222 species of breeding birds, making this
region the second-richest within the whole temperate broadleaf and mixed forest biome. One hundred and
forty species breed in the New England/Acadian Forest, of which the wood warblers, at twenty-three species,
are the most common. Many, like the black-throated green warbler and Blackburnian warbler, show a preferen-
ce for unmanaged, mature forests. The great attraction is insects: grubs, beetles, mayflies, moths, butterflies,
blackflies, and mosquitoes begin to emerge in spring from the ground, from the bark of trees, and from melt-
water, attracting a host of neo-tropical migrants, including redstarts, tanagers, and more than a dozen wood
warblers. They join the populations of resident birds like chickadees, nuthatches, and siskins. Most of the
forest birds are insectivores, whether they excavate bark, as woodpeckers do; glean insects from leaf and bark;
or snatch them from the air, as the flycatchers do.
Not surprisingly, the forests that support the greatest diversity of birds are the ones that have the greatest
structural diversity, thus providing many niches for insects. A large, multilayered forest with a rich groundcov-
er layer, an understory, and a large canopy supports more birds than a small patch of forest with a single layer,
such as a monoculture plantation.
This physiographic diversity not only attracts birds but also supports more species of small mammals and
amphibians. In New England there are approximately 338 common inland species. This diversity can be attrib-
uted to the wide array of habitats, which are a consequence of the elevation changes from the highest peaks of
the Appalachians to the tidal marshes of the coastline, as well as to the latitudinal gradients, which bring north-
ern and southern species together.
Characteristic large mammals of the region include black bear, red fox, snowshoe hare, porcupine, fisher,
beaver, bobcat, marten, muskrat, and raccoon—a total of fifty-eight nonmarine species in the Atlantic Mari-
time ecozone of eastern Canada and northern Maine. A number of large mammals have been extirpated from
the region, including elk, wolf, wolverine, and mountain lion, or eastern cougar, while the woodland caribou
persists as an endangered population only in the Gaspé Peninsula, having disappeared from both New Brun-
swick and Nova Scotia by the late 1920s.
Hundreds of cougar sightings have been reported in the Maritimes since the 1980s, and since 2002 six hair
samples have been collected from pheromone-equipped “hair poles” from New Brunwsick and Quebec, and
from a cougar hit by a truck in East Hereford in the Eastern Townships region of Estrie, Quebec, not far from
the New Hampshire border. dna analysis of the hair samples revealed that four of these animals, including the
one struck in Estrie, were of South or Central American origin. These results suggest that these cougar were
escaped or released animals or the offspring of once-captive animals. The remaining samples were of unknown
ancestry or from North American populations and might well be pet releases or the offspring of captive-bred
individuals. Genetic analysis indicates that the North American cougar is a single race and that the eastern cou-
gar, if it still exists, should be treated as the only valid subspecies occupying North America.
