Monday, February 11, 2013

Science Week 18: Mammals of the Seas

Yet again, Blogger ate my draft awaiting publishing. I guess I just need to get into a schedule where I can sit at the computer weekly and not store posts to set into place at later dates.
Even the sea monsters draw out the breast, they give suck to their young ones...Lamentations 4:3
Jeremiah, a prophet of old Israel, knew about the order of mammals that spends its whole life in water.  He called it the sea monsters and noticed the tender feeding of the young on milk.

List of Cetaceas, Wikipedia

To get you started:
Whale Lapbook, Homeschool Share
Whale Lapbook components, Lapbook Lessons

The order Cetacea contains 90 species of whales, dolphins, and porpoises. Since cetaceas only live in water and have long, streamlined bodies, some people mistake them for fish. How do we know they are mammals?
(Mammals are warm-blooded vertebrates that have hair, usually bring forth their young alive, and nourish them with milk).
Many adults have whiskers and some young have soft hairs early in life, or before birth. All cetaceas bear their single young alive and nourish it with milk. Whales, porpoises, and dolphins have powerful flukes that spread horizontally, unlike the vertical tails of fishes. As other mammals do, they breath air through lungs.  Most mammals have 2 pairs of limbs, but cetaceas have only a single pair. the manatee is another mammal without a rear pair of limbs.

The cetaceans most important sense is hearing, with sight a close second. Just as bats in total darkness find their way with echolocation (remember week 12/bats?), so do cetaceans. God has so delicately constructed these almost unbelievable hearing organs that the dolphins can sort out all the echoes of his own cries from dozens of other signals raised by other citizens of the sea, By these sounds the size, shape, and speed, distance away, and direction of the movements of other creatures are understood as well as the outlines of the sea bottoms, and other physical features.

Song of the Whale

Kingdom of the Blue Whale

PBS: Realm of the Killer Whales

Cetaceans are divided into 2 main groups. The toothed whales have a single blowhole and flippers with four rows of bones. The toothless whales breathe through a double blowhhole and have flippers with five rows of bones. Toothless whales have hundreds of thin, flexible bones called baleen in their mouths. Fine mesh hangs from the inner surfaces of each one. The baleen whales do not swim below 325 feet. They feed on young shrimps, snails, sea jellies, lobsters, sponges, crabs, fishes, sea stars, and various one-celled creatures. these are called plankton or krill. 
In former times, whale baleen was used in making umbrella ribs, fishing rods, and buggy whips. In 1897 whalebone, or baleen, sold for $5000 a ton. Metal and plastics are used for these purposes now. 

Photo displaying dozens of baleen plates. The plates face each other, and are evenly spaced at approximately 0.25 inches (1 cm) intervals. The plates are attached to the jaw at the top, and have hairs at the bottom end.
Baleen is a filter-feeder system inside the mouths of baleen whales. The baleen system works when a whale opens its mouth underwater and then water pours into the whale's mouth. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and is made of keratin, the same substance found in human fingernails and hair. Some whales, such as the bowhead whale, have longer baleen than others. Other whales, such as the gray whale, only use one side of their baleen. These baleen bristles are arranged in plates across the upper jaw of the whale. Baleen is often called whalebone, but that name also can refer to the normal bones of whales, which have often been used as a material, especially as a cheaper substitute for ivory in carving.

photo and Where Whales Live text via
So where do whales live?
  • Killer Whale – The killer whale can be seen traveling throughout the worlds major oceans, but they typically prefer cooler climates compared to the tropical climates found near the equator. As stated earlier the migration pattern of these whales is more often than not determined by their prey’s migration.
  • Gray Whale – Gray whales are often found swimming in the eastern and western north pacific ocean during feeding season and will migrate towards the Baja peninsula of mexico and the southern golf of california where they mate and bare off spring during their mating period.
  • Humpback Whale – While humpback whales can be found traveling all over the world they prefer the cold waters in and around the Arctic and Antarctic oceans.
  • Blue Whale - Blue whales (like humpback whales) can also be found traveling all the major oceans. They can often be seen swimming in the colder regions during feeding season and will migrate towards tropical waters when mating.
  • Bowhead Whale – Unlike other species of whale bowhead whales are generally found traveling in Arctic/sub Arctic oceans year round and aren’t known for making long migration trips.
  • Minke Whale - There are two known species of minke whales currently in existence, the common or north Atlantic minke whale (which inhibits the north Atlantic waters) and the Antarctic or southern minke whale (which lives in the Antarctic region south of the equator). Due to differences in climate changes in both regions the two species of whale do not meet one another during mating periods because their mating seasons are different.
  • Sperm Whale - Sperm whales can be found in all of the worlds major oceans. Female sperm whales and their young prefer to stay in near tropical waters all year-long while the males can be seen traveling back and forth from the colder climates to the warmer climates during mating periods.
  • Beluga Whale – Beluga whales are generally found swimming in shallow coastal water in and around Arctic waters. Depending on the area and environment the whale is in some beluga whales will make seasonal migration trips while others will only travel within a small localized area.
  • Narwhal Whale – Narwhal whales can be found living in or near the Canadian Arctic and Greenlandic waters throughout the year. During the fall and winter they migrate away from the coastal waters (off shore) in order to avoid large areas of ice and frozen water and will move back towards coastal grounds during the warmer spring and summer months.
Largest Blue Whale Colony, Sri Lanka

The whale's blowholes have powerful valves. As it comes to the surface, the hole opens. A volume of compressed air rises perhaps 20 feet, taking along any water that happens to be over the blowhole. A deep breath rushes into the lungs and in 2-3 minutes is absorbed by the blood. The whale blows again and refills its lungs. Finally, after a number of blows, the whale is fully recovered and ready for another long breath-holding dive.  Oxygen enters even the muscles. The lungs are folded flat. The whale jack-knifes, then as it goes down, raises its flukes from the water in a backward kick that sends it to the bottom. The heartbeat slows to about 1/3 of its usual rate. In the cold, blood leaves the skin, flippers, and flukes to enter the heart and brain. The body temperature drops. Many whales have heating systems that keep them warm in icy seas. This system overheats when the mammal is stranded on the beach. Without the support of the ocean currents, the heavy blubber on a whale's body will prevent its lungs from filling up. A large cetacean will suffocate under its own weight when it is not in the water.

Whaling History Notes:
History 1800s Whaling,
A Right Whale study, 5 lessons from Wheelock
....Metompkin and Her Story online here
Herman Melville's Moby Dick free online
ThinkQuest Whaling page

Properties of Underwater Accoustics with live streaming
Humpback whale songs, Ocean Mammals Institute
NOAA Fisheries, Dept.of Protected Resources has some nice lesson plans on whales for teachers and students
Enchanted Learning, Whales
Defenders of Wildlife, Whales
UCMP Berkley, Intro to Whales
Whale behavior, Whale Trust
Great (Baleen) Whales also check out links at end of article
Whale Facts,, such as...
..........Whales rest one-half of their brain at a time when they sleep.
The way whales "sleep" may sound strange to us, but makes sense when you think of it like this: whales cannot breathe underwater, which means they need to be awake just about all the time in order to come up to the surface when they need to breathe. So, whales "sleep" by resting one half of their brain at a time. While one half of the brain stays awake to make sure the whale breathes and alerts the whale to any danger in its environment, the other half of the brain sleeps.
bottle-nosed dolphin

Dolphin lapbook from HomeschoolShare
Island of the Blue Dolphins lapbook, Notebooking Nook
   full length movie here on YouTube
Dolphin Facts, Marine Life

The smaller toothed whales, called dolphins, having been kept in captivity, have learned to mimic the sounds of human conversation as many parrots and myna birds do. In captivity, they can successfully be trained to do various sea-faring tasks, as evidenced by Morgan, a pilot whale trained by the U.S. Navy.
Porpoises live on the northern Atlantic coast, and on the Pacific coast south to California. They feed mainly on fish which they gobble without much chewing. They remain underwater only a few minutes at a time. Dolphin and porpoise spouts are not visible.

Mother Whale and Calf

A great whale's milk glands can squirt milk up to a distance of 6 feet. Located in two folds of skin, they deliver a rich milk that is more than 1/3 fat. The cow usually turns on her side so the calf can drink with its blowhole out of the water. The calf adds about 230 lbs a day, gaining a ton every 9 days. Their rate of growth slows as they mature. They will continue nursing for 9 months. They may be 8 years old before they themselves can become parents.
This slow reproduction rate makes it impossible for the whales to multiply as fast as they are being hunted and killed.  Speedy catcher ships equipped with bomb-carrying harpoons shot from cannons, and with underwater detecting devices, fan out from modern factory vessels that completely process a whale's body in less than an hour. Along with widely cruising spotter planes, these outfits regularly visit the whale's feeding grounds in the Atlantic and Arctic. Since 1925, 2 million whales have been slaughtered and changed into oil, meat, and fertilizer. At present, it is estimated that we lose 50 thousand whales every year.
No product made of the body of a whale can be legally brought into the United States thanks to the Marine Mammal Protection Act, passed in 1972. Fifty-six other countries have agreed to protect completely tghe blue, the humpback, the right, the gray, and the bowhead whales. Only native peoples are not covered by this law.
New Bedford Whaling Museum, Whaling History 1861-1987

Access the Jacques-Yves Cousteau channel on YouTube here.

David Schrichte manatee photo

The manatee, also called the sea cow, is a tropical vegetation-eating water mammal. Like whales, it has no hind limbs and swims by up and down motions of its horizontal, very round, flukes. A full-grown manatee may eat as much as 100 lbs of water plants daily, scooping them into a big-lipped mouth with its flippers. Manatees feed with their head and shoulders out of the water. They drift slowly about the warm bays and lagoons of southern Florida. They live mostly in the protected sanctuary of the Everglades National Park, which will help allow the species to continue.
The milk glands of the manatee are on its chest, and the mother floats upright in the water, clasping her single young one with her flippers while it nurses. As the mother manatee grazes on water plants, the father holds the calf in his flippers. The manatee infant is cradled in the flippers of either parent for some weeks after birth. Nearly 2 years pass before the young is left to make its own way.

Manatee, A Gentle Giant

Save the Manatee Club...listen to their calls here...see diagrams of their anatomy here...a manatee book list here...Save the Manatee coloring book PDF...

Did You Know?Manatees only have molars, which are used to grind food. As they wear down and fall out, they are replaced with new teeth.Manatees only breathe through their nostrils, since while they are underwater their mouths are occupied with eating! A manatee's lungs are 2/3 the length of its body.

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