1. 2011 Pearson Education, Inc.Marine Mammals Land-dwelling ancestors Warm-blooded Breathe air Hair/fur Bear live young Mammary glands for milk

2. 2011 Pearson Education, Inc.Major Marine Mammal Groups 3. 2011 Pearson Education, Inc.Order Carnivora Prominent canine teeth Sea otters Polar bears Pinnipeds Walruses Seals Sea lions Fur seals 4. Polar Bear, Pittsburgh Zoo and Aquarium 5. 2011 Pearson Education, Inc.Carnivora 6. 2011 Pearson Education, Inc.Seals vs. Sea Lions and Fur Seals Seals lack prominentear flaps Seals have smallerfront flippers Seals have fore flipperclaws Different hipstructures Different locomotionstrategies 7. 2011 Pearson Education, Inc.Order Sirenia Herbivores Manatees Coastal areas of tropicalAtlantic Ocean Dugongs Coastal areas of Indianand western PacificOceans 8. 2011 Pearson Education, Inc.Order Cetacea Whales, dolphins, porpoises Elongated skull Blowholes on top ofskull Few hairs Fluke horizontaltail fin for verticalpropulsion 9. 2011 Pearson Education, Inc.Order Cetacea 10. 2011 Pearson Education, Inc.Order Cetacea Adaptations toincreaseswimming speed Streamlinedbodies Specialized skinstructure 80% water Stiff inner layer Narrow canalswith spongymaterialMr. Bantay at Discovery Cove, Florida (November 2011). 11. Discovery Cove, Florida. November 2011 12. 2011 Pearson Education, Inc.Order Cetacea Adaptations for deep diving Use oxygen efficiently Able to absorb 90% ofoxygen inhaled Able to store largequantities of oxygen Able to reduce oxygenrequired for noncriticalorgans Muscles insensitive tobuildup of carbon dioxide Collapsible lungs 13. 2011 Pearson Education, Inc.Order Cetacea Suborder Odontoceti(toothed) Dolphins, porpoises, killer whale, sperm whale Echolocation todetermine distance anddirection to objects Determine shape, sizeof objects 14. 2011 Pearson Education, Inc.Dolphins vs. Porpoises Porpoises Smaller, morestout bodyshape Blunt snout Triangular,smaller dorsalfin Blunt or flatteeth Dolphins Larger, morestreamlinedshape Pointy teethlike killerwhales (orca) 15. 2011 Pearson Education, Inc.Echolocation Good vision of marine mammals is limited by oceanconditions. Mammals emit clicks of different pitches. Low frequency great distance High frequency closer range Dolphins can detect schools of fish at more than 100 meters(330 feet). 16. 2011 Pearson Education, Inc.Echolocation Toothed whales send sound through water. Sound is reflected, returned to the animal, andinterpreted. An evolved inner ear structure may help toothed whalespick up sounds. Increased marine noise pollution may affect cetaceanecholocation. 17. 2011 Pearson Education, Inc.Echolocation 18. Sofar -Sound Frequency and Ranging channelUnderwater sound is used by many marine animals to sense theirenvironment, communicate, and find food. Underwater sound is also used by marinescientists to measure ocean depth, track objects in the water, and determine oceantemperature changes. Transmission of sound in the ocean is affected by watertemperature, pressure, and salinity. The normal variations in these properties with depthcombine to produce a minimum sound speed at a depth of about 1,000 meters. At thisdepth, sound travels relatively slowly compared to the speed of sound through water atgreater and lesser depths. The depth zone centered around this level of minimum soundspeed is called the Deep Sound Channel, and is also known as the SOFAR (soundfixing and ranging) Channel. Sound entering this layer tends to be trapped andchanneled along it, making this layer extremely efficient in transmitting sound forthousands of kilometers through the ocean. 19. 2011 Pearson Education, Inc.Intelligence in Toothed Whales Large brainsrelative to bodysize Communicatewith each other Trainable 20. 2011 Pearson Education, Inc.Order Cetacea SuborderMysticeti Baleen whales 21. Blue Whale, NYC Natural MuseumOrder Cetacea Blue whale, finback whale, humpback whale, graywhale, right whale 22. Right Whale 23. 2011 Pearson Education, Inc.Use of Baleen Fibrous plates of baleen sieve prey items Vocalized sounds for various purposes 24. 2011 Pearson Education, Inc.Gray Whale Migration 22,000 km (13,700miles) annualmigration from coastalArctic Ocean to BajaCalifornia and Mexico Feeding grounds inArctic (summer) Breeding and birthinggrounds in tropicaleastern Pacific (winter) 25. 2011 Pearson Education, Inc.Whales as Endangered Species Fewer whales now thanbefore whaling International WhalingTreaty Hunting of gray whalebanned in 1938 Gray removed fromendangered list in 1993as populationrebounded 26. 2011 Pearson Education, Inc.Gray Whale Friendly Behavior 27. 2011 Pearson Education, Inc.Whaling International Whaling Commission (IWC) 1948 established to manage whale hunting In 1986, 72 IWC nations banned whaling Three ways to legally hunt whales: Objection to IWC ban Scientific whaling Aboriginal subsistence whaling