|
The North Atlantic right whale, also known as the
northern right whale or the black right whale, is
a type of whale belonging to the taxonomic genus eubalaena
along with two other species of right whale. More
specifically, its scientific name is Eubalaena glacialis.
North Atlantic right whales can be found in both the
east and west of the North Atlantic Ocean, although
the population in the east is so small that it is
considered effectively extinct.
Typically, North Atlantic right whales measure between
43 and 52 feet in length and weigh between 88,000
and 150,000 pounds. The largest North Atlantic right
whale ever measured, however, was 60 feet long and
weighed 234,000 pounds. The North Atlantic right whale
can be either dark gray or black in color, and can
have white patches on its underside as well as white
callosites, which gain their color from whale lice.
Though North Atlantic right whales are technically
carnivores, they are baleen whales and therefore filter
feeders, meaning that they consume fairly small organisms
and are far from aggressive predators. They subsist
predominantly on small crustaceans and other small
invertebrates, and typically feed by slowly swimming
through areas of high concentration of these organisms.
They compete for food with some other baleen whale
and filter-feeding shark species for food, but have
not been observed in conflict with these species.
The North Atlantic right whale begins reproducing
at the age of about nine or ten years, at which time
females gestate for a year. The western population
of North Atlantic right whales reproduce in the winter
months off the coast of the southeastern United States.
There is a gap of about three to six years in between
birthing among North Atlantic right whales, a number
that has grown recently.
North Atlantic right whales can be observed at the
surface of the water most often during their mating
season, since groups of right whales engage in courting
activities at the surface in what is called a surface
active group. Outside of this time, they seem to be
relatively inactive at the surface, though this conclusion
may simply be derived from the fact that there are
far fewer North Atlantic right whales than there are
other right whales.
The North Atlantic right whale is one of the most
endangered species of whale; hardly more than ten
are believed to exist in the eastern North Atlantic,
and only about 400 are believed to exist in the western
North Atlantic, their numbers having been crippled
in large part by whaling. North Atlantic right whales
face great threats from injury and death caused by
collisions with ships as well as becoming entangled
in fishing gear and traps. Climate change also threatens
the population, as the North Atlantic right whale
fares best in a fairly static environment with stable
resources.
|
