Do Now #6

• What are some of the behaviors that you have seen cetaceans do?

• What parts of their bodies allow them to do those behaviors?

Cetacean Anatomy & Behavior

EQ: What adaptations do cetaceans have?

Anatomy

Adaptations• Large, steam-lined body• Almost entirely hairless• Contain a thick layer of fat called

blubber• Blowhole on top of head for air

exchange– Connects directly to the lungs– Muscles control when it opens and

closes

• Drink salt water

Adaptations• Some species make very deep

dives in search of food– Use oxygen more efficiently & have

more red blood cells to hold it– Decrease heart rate & redistribute

blood– Most will only stay under for 10-15

min but can stay under for ~40 min– Sperm whales can dive to depths

over 1000m for 1.5-2 hours

• Fast swimmers– Powerful muscles running nose to tail– Orca is the fastest at 30 mph

Sensory Abilities• Large brains

– Brain-to-body size second only to humans

• Use sound communication– Produce unique whistles with pod

dialects based on geographic location

• Some species use sound to identify objects known as echolocation

• Eye sight is as good underwater as out of the water

Dolphin Human

Echolocation• Evolved for toothed whales in murky

waters• A series of high frequency clicks are

made in the airway below the blow hole• Bounce the sound off their mouth bones

and focus them using their melon• Receive sound through their lower jaw

Intelligence• Social structure revolves around groups

called pods– Communicate, have hierarchies, work

together to hunt & raise young• Play

– Jumping, bubble rings & surfing• Creativity

– Develop new, unusual responses to changing situations

• Tool Use– Use sponges to protect noses while

foraging in the sand• Cross-species Cooperation

– Have helped other whale species as well as humans

– Learn behaviors from humans

Intelligence

Migrations• Only done by some whales• Seasonal move from areas of

cold (summer) to warm water (winter) to to mate & give birth

• Cold waters have abundant food

• Warm waters are more conducive to raising young

• Gray whales migrate the longest traveling 10,000-12,000 miles round-trip

• Use ‘sonar’, currents & magnetic field to guide migrations

Reproduction• Reproduce every 2-7 years

depending on species• All reproductive organs are

internal until needed– Helps them stay streamlined

• Often male competition for breeding partners

• Give birth to a single, live young after a year gestation

• Care for their young for several months to several years

Populations• Whales live from 25-100 years

– Dolphins: 25-50 years– Humpbacks: ~40 years– Fin & Blue: 80+ years

• Many population numbers are rebounding from depletion by whalers– Toothed whales are least

endangered– Most baleen whales are endangered– River dolphin are most endangered– Some are so rare to see we cannot

accurately count their numbers

Whales of NJ• Most commonly seen are:– Humpback– Finback– Bottlenosed dolphin

• Other species include sperm, sei, blue, and right whales and Atlantic white sided, common and Risso’s dolphins

Test Tomorrow!• Cram sheet due

tomorrow

Notebooks:• 6 Do Nows • Salinity Notes– Salinity– Changes in Seawater

• Cetacean Notes– Classification &

Evolution– Anatomy & Behavior