Humpback
Whales in Hawaii Breeding and Birthing
Humpback whales are thought to breed and give
birth in or near Hawaiian waters. It is thought that they
prefer warm, shallow waters for these activities, though
neither activity has yet been observed or documented. Humpback
Whales have complicated courtship behaviors. Male humpback
whales have been observed surrounding a female and competing
with each other to get close to the female. Sometimes males
lunge at and bash into each other.
Humpback whales mature sexually at age 6 to
8. Female humpback whales give birth every two to three
years. The gestation period is 11 or 12 months. Like all
mammals, humpback whale calves are born alive. Humpback
whale babies weigh up to 3000 pounds (1.4 metric tons) and
are ten to fifteen feet (4 to 5 meters) long. Calves feed
on mother's milk for approximately a year before they are
weaned. Humpback whale milk is very rich, containing as
much as 50% fat and humpback whale calves can consume 100
gallons or more of milk a day. It is thought that a baby
humpback whale can gain as much as 100 pounds and grow an
inch a day. They can often be seen playing along side their
mothers, practicing breaching and slapping the water. Humpback
whale calves can dive for an average of 3 to 5 minutes.
They are very curious and rely on their mother for protection
from predators, boats and other dangers.
How
big is a Humpback Whale?
Humpback whales that visit Hawaii weigh from
25 to 40 tons. Adult male humpback whales are from 40 to
48 feet long. Adult female humpback whales average 45 to
50 feet (over 15 meters). A humpback whales head takes up
about one third of the body length. Humpback whales most
recognizable feature are their long flippers which extend
up to 15 feet (5meters) and are from one quarter to one
third the length of their bodies. The humpback whales scientific
name, Megaptera novaeangliae, meaning "long-winged
New Englander,” refers to these pectoral or side fins.
A humpback whales tale fin, called a fluke, can measure
15 feet (5 meters) across. The white pattern found on the
bottom of the fluke is unique to each humpback whale and
is used to identify individual whales, just like human finger
prints.
Humpback
Whales in Hawaii on a Diet
One amazing fact about humpback whales in
Hawaii is that they are fasting. The incredibly clear Hawaiian
waters contain very little phytoplankton or krill, microscopic
plant life and minute crustaceans, which Humpback whales
feed on during the summer in Alaska and more northern climes.
For 4 to 6 months they live off of their blubber, or fat
layer. Average weight loss during the winter migration and
stay in Hawaii is about 25%, or 6 to 8 tons. Humpback whales
can lose up to 1/3 of their body weight. Mothers nursing
young are particularly under stress.
Humpbacks whales are baleen whales. They filter
food through a large array of baleen plates. They eat krill,
anchovies, cod, sardines, mackerel, capelin, and others
sorts of schooling fish by sifting them out of the water
with the baleen.
Some humpbacks make "bubble nets"
with the air that they release from their blow holes to
corral their food. The humpbacks swim up from the deep in
a spiral patter while releasing a steady stream of bubbles.THe
bubbles surround the prey and corrals the fish or plankton
so the humpback whale can swim through the center with jaws
open for a great gulp of food.
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