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The background information will be submitted in outline form so
teachers may chose which topics they wish to focus on in greater
detail.
WHALES-GENERAL INFORMATION a.Mammals-Whales give birth to live
young, thermoregulate(keep their internal body temperatures stable
as outside conditions vary), have mammary glands, and hair. b.Whales
are part of a group called the Cetaceans. This group includes whales,
porpoises, and dolphins.Most have a muscular tail with flukes, blubber
for warmth and buoyancy, and used by man for items like oil and
soap. They breath with lungs and use a blow hole with either one
or two openings to breath. Some speices can go over on hour without
coming up for air.
Cetaceans also have the ablility to dive up to 7000 feet under
water. They have collapsable lungs to deal with pressure changes
and which helps keep nitrogen out of their bloodstreams.They have
adapted lungs which store higher concentrations of oxygen than most
mammals.There are 90 species of cetaceans known to man. c.Two groups-Toothed
and baleen Toothed whales include orcas, sperm whales, dolphin,
and porpoise, etc.Toothed whales have one blowhole opening. They
swallow food whole and mainly feed on fish, squid, seals, shark,
otters etc.
There are 80 species of toothed whales. Baleen whales include the
humpback, fin, minke, blue, gray whales etc. There are 11 species
of baleen whales known. Baleen whales filter feed using large keratin
plates called baleen, which hang from the top of their mouths. They
take large gulps of water, some even have folds in their throat
to allow it to stretch while feeding, close their mouths and filter
the water out through the spaces between plates of baleen. Left
behind is the krill, plankton, shrimp, and squid which can be scraped
off the baleen by the whale's tongue.Baleen whales tend to make
up most of the larger whales with the blue whale being the largest
creature on earth. d.Some whales are migratory and travel north
and south to breed and give birth, while others are residential
and remain in the same area to feed, mate, and give birth.Some travel
in groups called pods, while others travel alone. Migratory patterns
are unique to each species. e.Whale size- Cetaceans can range in
size from a few feet and 100 pounds to 100 feet and 200 tons. Some
species already weigh two tons at birth. f.Most whales have the
ablility to communicate with one another by echolocation, vocalizations,
or displays out of, and under water.
TRACKING/IDENTIFYING WHALES IN THE WILD a.Most whale species have
a distinct feature that researchers utilize to track individual
whales or groups of whales.Some examples- Orcas-saddle behind the
dorsal fin Gray-lumps of barnacles on the front of their head Humpbacks-white
patterns on underside of tail flukes b.Researchers use these distinctions
to help understand family patterns as well as migratory patterns
of whale groups. They can also more easily document which whales
are appearing in what areas on an annual basis. The websites mentioned
are a helpful guide to this outline and have many pictures which
would be useful in the lecture part of the activity.
HUMPBACK a.Baleen whale found in every ocean in the world b.One
of the largest creatures on earth, weighing up to forty tons c.Migrate
in groups north and south along coastlines to feed, mate, and give
birth d.Exhibit social behaviors like spyhopping,lobtailing, breaching,
singing, and tail slapping. Most photos are a result of one of these
behaviors. e.Humpback populations were dangerously low before laws
on commercial and subsistance whaling were passed. Now populations
are estimated at 40,000. f.Still many problems facing humpback populations
today-illegal hunting, overfishing, pollution. For more detailed
information or some good pictures of humpbacks, refer to websites
listed.
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