Geoscience Reference
In-Depth Information
merge, intent on taking the tiny craft with it. Piccot's twelve-year-old son had the wit to grab a hatchet and
hack off the tentacle and arm, and the giant squid slipped away, darkening the water with jets of ink, but not
before yielding proof that the mythical kraken, or giant squid, written about by authors from Aristotle to Jules
Verne, actually existed in nature.
Although giant squid roam the world's oceans, Newfoundland appears to be unique in that it is the only
place where they have regularly grounded. Squid belong to the cephalopods (literally “head-footed”), a marine
family that includes the octopus and cuttlefish. Perhaps the most remarkable organs of the giant squid are their
dinner-plate-sized eyes, which are well adapted for seeing in the water by virtue of a movable lens. Whereas
the human eye has a point of focus on the retina, the squid have an equatorial band where they are able to fo-
cus, making their vision potentially twice as acute as a human's. Sight, more than any other sense, dominates
squids' lives—they are thought to communicate with each other by means of bioluminescent chromatophores,
which flash and change color from pale gray to brick red. And their ability to focus over a wide range allows
them to track prey and predator alike.
The only known predator of the giant squid is the sperm whale, whose stomach contents often contain frag-
ments of giant squid or, on occasion, a whole animal. Eyewitness accounts of titanic clashes between these two
pelagic giants were widely circulated among 19th-century whalers.
GIANT SQUID
GEORGE RIVER HERD
I FIRST
saw a George River caribou on the Labrador coast, in late summer, when an Inuit hunter returned from
a successful hunting trip near the abandoned northern settlement of Hebron. The next time I saw caribou was
on the shores of Hudson Bay, where I was staying with Cree hunters at a spring goose camp. Both of these an-
imals belonged to the George River herd, which at its peak, in the mid-1990s, numbered 800,000 animals. It
was not only the largest caribou herd in the world but perhaps the largest herd of free-ranging ungulates on
Earth, rivaling African ungulate populations. Yet these animals survive and proliferate in one of the harshest
environments on the planet, the boreal forest and tundra of the Labrador-Ungava Peninsula.
The George River herd belongs to the migratory forest-tundra ecotype (a locally adapted variant) of the
woodland caribou. They range over a vast area of nearly a half million square kilometers (200,000 square
miles), encompassing most of northern Quebec and Labrador, from the Labrador Sea to Hudson Bay. In the
past, this herd has undergone wild fluctuations, from very high numbers in the late 19th century to such
scarcity twenty years later that biologists contemplated penning some in a zoo to ensure the survival of the
species. In 1958, the herd was estimated at only 2 percent of its peak size; today, the herd is again in decline,
with the latest estimate pegged at 385,000 animals.
Caribou subsist largely on lichens, which are very slow-growing. Limitations on herd growth may be
delayed, however, as the herd compensates by expanding its range, as the George River herd did. Range ex-
pansion itself exacts an energetic cost, and eventually food limitations become apparent when new ranges can
