Whales

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Whales
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Fossil Record

• Shows that some land animals began to make the
  transition to sea animals about 50 million years
  ago.

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Mammals

• Whales are mammals and all mammals share 3
  characteristics
• Hair
• Feed young with milk from mammary glands
• Have a 4-chambered heart

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Whales and Dolphins belong to the Order
Cetacea There are about 80 species
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Whales versus Dolphins

• Whales are largest and dolphins and porpoises are
  the smallest.

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Baleen Whales

• Two blowholes
• Baleen plates filter feeders
• Plates grow to several feet in length
• May be several hundred in one animal
• Flat on outer edge, bristles on inner edge trap
  small organisms
• Krill food source for many baleen whales
• Includes the humpback, blue, finback, right, sei,
  and gray whales.

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Baleen
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Toothed Whales

• One blowhole
• Have teeth to seize prey
• Include the Sperm, killer, pilot, beluga,
  dolphins and porpoises
• Killer whales top carnivores

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Baleen Whale vs. Toothed Whale Size
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Whale Reproduction

• Fertilization and development are internal
• Whales breed about every 3 years and the female
  whale, or cow, stays pregnant between 11 and 18
  months.
• Whales are born tail first.
• Nurse for 6-10 months
• A blue whale calf drinks the equivalent of 400
  glasses of milk per day and the milk is 50 fat
  in content.

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Whale Birth
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Adaptations and Behaviors

• Whales breathe through their blowholes which are
  connected to their lungs, not their stomachs
  (Dory and Marlin would never have been shot out
  the blowhole).
• Blowhole is on the dorsal side of their bodies,
  up on their head, so it surfaces first
• Baleen whales have 2 blowholes, toothed whales
  have 1 blowhole

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Blowhole
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Swimming

• Whales swim by the up and down movement of their
  hind flippers or tail flukes
• The dorsal fin helps keep them on course
• Pectoral fins are used for steering, braking and
  balance.
• The bones inside the fin are similar to the bone
  structure of the hands of land mammals and whales
  still have hip bones.

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Whale Skeleton
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Diving

• Whale uses its pectoral fins to change from
  horizontal to vertical.
• The tail flukes then push the body down into the
  water head-first

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Lunging swim up to the surface and engulf food
(bubble net)
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Lobtailing

• Waves tail in the air then smashes it into the
  water.
• Not fully understood by scientists
• May be a sign of aggression or a way to announce
  its presence.

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Spyhopping

• Whale raises head above the waters surface to
  look around for a few seconds.
• May be a sign of curiosity

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Breaching leaps almost completely out of the
water and crashes back down with a huge splash.
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Whale Migration

• Whales spend the summers feeding in the waters
  off the Bering Sea and Arctic Ocean. These
  waters are nutrient rich and contain a lot of
  plankton.
• During the winter, whales migrate to warmer,
  shallow waters around Baja California (Gray
  Whale) or Mexico (Humpback) to breed and have
  their young.

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Migration Map
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Keeping Warm

• Blubber keeps whales warm (they are endothermic
  or warm blooded) in water.

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Echolocation- form of sonar where the whale
bounces sound off of objects to detect objects in
the water
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Stranding

• Stranding is where a dolphin or whale swims into
  shallow waters and becomes beached.
• The whales die as their internal organs are
  crushed by their own body weight.
• It is puzzling because, for whatever reason,
  their echolocation system is not working.
• May be caused by PCBs and DDT or natural toxins
  in the water.

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Mass Stranding
Pilot Whales are the most commonly stranded
whale. May have been caused by the use of sonar
by navy ships.
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Threats to Cetaceans

• 1. Hunting both regulated and unregulated
• 2. Pollution PCBs and DDT may interfere with
  echolocation causing strandings
• Oil slicks also a big problem
• 3. Overfishing or killing of whales food
  source(s).
• 4. Noise interfering with echolocation
• 5. Unintentional tangling in nets used for other
  purposes (dolphins in tuna nets)

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Blue
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Humpback
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Right
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Minke
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Gray
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Toothed Whales
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Spyhopping
Narwhal
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Sperm
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Beluga
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Humpbacks are identified by the markings and
shape of their tails (Also an example of
lobtailing)