• Incredible Journey
    In order to fully breach the surface, this 30-ton animal must swim upwards at about 29 kilometers per hour.

    Photograph by Lisa Winchester, MyShot

    Spot the Humpback
    Humpback whales are known for more than just their wandering ways. The marine mammals songsa series of moans, howls and crieshave long fascinated scientists, while humpbacks have also been called one of the most acrobatic whale species due to their frequent displays of breaching and flipper slapping. In addition, the animal is easily identifiable by its pronounced ventral pleats, or grooves that run along its belly like ridges on a potato chip.

    By Stuart Thornton

    Friday, October 29, 2010

    With a barrel-shaped body and pectoral fins protruding like oversized wings, the humpback whale is not designed for speed. Yet the marine mammal, which can reach lengths of 50 feet, is known for its impressively long travels between warm-water breeding grounds in the winter and cold-water feeding grounds during the summer.

    “Humpbacks arguably make the longest documented migration of any mammal,” says marine mammal research biologist John Calambokidis, who has studied the whales since 1986.

    While some humpback whales have been known to migrate from the Antarctic Peninsula all the way to the tropical waters off Costa Rica, the marine mammals are not exactly known for their ability to swim fast.

    “The speeds that a lot of these whales that make long migrations travel at is often not that impressive,” Calambokidis says. “In other words, they can be just as slow as three to five miles an hour. But the impressive part is they are doing that 24 hours a day. That means they can be covering 100 miles in a day. They can cover these rather long distances . . . in a month or two.”

    Although humpbacks were once hunted to near extinction, since achieving federal endangered species status their population has rebounded. They are found in oceans all over the world. The Northern Hemisphere populations reside in the North Atlantic Ocean and the North Pacific Ocean. The southern group spends its time feeding off the coast of Antarctica. During the winter, both groups head to warmer waters for breeding and raising their young.

    According to Calambokidis, there is some scientific debate about why humpback whales migrate so far. It might be because the giant creatures, and their vulnerable newborn calves, need warmer waters to reduce energy loss during the winter.

    There’s also the possibility that humpback whales migrate as a strategy to escape predation by killer whales. Calambokidis says that humpback whales are able to defend themselves against killer whale attacks easier if they are in shallow, warm waters rather than deeper cold-water ocean regions.

    During their three-week to two-month migrations, humpback whales seldom eat. They live off body fat accumulated before embarking on their journey. Calambokidis says that it’s hard to tell if humpbacks fatten up as a way of preparing for their travels or because they somehow know that prey will be less abundant in the near future. Humpback whales mostly eat tiny shrimp called krill, which are found in the icy waters of the Arctic and Antarctic.

    “You could say they are fattening up for the long migration,” he says. “If they do the long migration because of prey that aren’t as abundant in the winter, it’s kind of a chicken and egg thing. It’s preparing to migrate by feeding heavily, but the reverse is also true: the long migration is driven by the fact that [the whale] can only feed heavily during part of the season.”

    How the humpback whales know where to travel during their migrations still has scientists stumped. “I am not sure anyone has a clear answer to this other than speculation,” Calambokidis says.

  • Term Part of Speech Definition Encyclopedic Entry
    abundant Adjective

    in large amounts.

    accumulate Verb

    to gather or collect.

    acrobatic Adjective

    having good balance, flexibility, and the ability to perform athletic jumps and other activities.

    Antarctic Noun

    region at Earth's extreme south, encompassed by the Antarctic Circle.

    Arctic Noun

    region at Earth's extreme north, encompassed by the Arctic Circle.

    Encyclopedic Entry: Arctic
    arguably Adverb

    in a questionable or easily challenged manner.

    biologist Noun

    scientist who studies living organisms.

    breach Verb

    behavior exhibited by whales, when they jump above the surface of the water.

    breeding ground Noun

    place where animals mate, give birth, and sometimes raise young.

    coast Noun

    edge of land along the sea or other large body of water.

    Encyclopedic Entry: coast
    couple Noun

    two of something, or a pair.

    debate Verb

    to argue or disagree in a formal setting.

    document Verb

    to keep track of.

    embark Verb

    to leave or set off on a journey.

    endanger Verb

    to put at risk.

    fascinate Verb

    to cause an interest in.

    fat Noun

    material found in organisms that is colorless and odorless and may be solid or liquid at room temperature.

    feeding ground Noun

    region where organisms go to eat.

    flipper slap Noun

    behavior exhibited when a whale raises a pectoral fin above the surface of the water and then slams it down with great force.

    identifiable Adjective

    able to be recognized.

    killer whale Noun

    carnivorous whale, actually the world's largest species of dolphin. Also called an orca.

    krill Noun

    small marine crustacean, similar to shrimp.

    mammal Noun

    animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

    migration Noun

    movement of a group of people or animals from one place to another.

    pectoral fin Noun

    limblike structures located on the side of the body of some fish.

    population Noun

    total number of people or organisms in a particular area.

    possibility Noun

    chance or likelihood.

    predation Noun

    behavior of one animal feeding on another.

    prey Noun

    animal that is hunted and eaten by other animals.

    protrude Verb

    to stick out or swell.

    reduce Verb

    to lower or lessen.

    reside Verb

    to live in a place.

    seldom Adverb

    not very often.

    shrimp Noun

    animal that lives near the bottom of oceans and lakes.

    strategy Noun

    plan or method of achieving a goal.

    stump Verb

    to confuse.

    ventral pleat Noun

    long grooves in the skinunder a whale's mouth that expand when the whaletakes in water.

    whale Noun

    largest marine mammal species.

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