Mammal Charateristics & Classification
What class includes all animals studied in this unit?
Mammalia
What suborder includes baleen whales?
Mysticeti
What are two types of Sirenians?
Manatees & dugongs
What visible structures do sea lions have that seals lack?
External ear flaps
What does sound travel faster in water than in air?
Water molecules are closer together than gas molecules, which allow sound particles to travel faster from molecule to molecule
What characteristic allows mammals to maintain a constant internal body temperature?
Endothermy
What process do toothed whales use to locate prey and navigate?
Echolocation
What is the primary diet of Sirenians?
Seagrass/plants (only marine mammals that are fully herbivorous)
What structures do walruses use for social dominance and maneuvering on ice?
Tusks
Name 2 natural sources of ocean noise.
Lighting, earthquake, underwater volcano, ice cracking, whale songs, oyster toadfish, plus more
What type of reproduction do most mammals use?
Viviparity
What material is baleen made from?
Keratin
True or False: Sea otters are keystone species that control sea urchin populations.
True
What pinniped family includes the true seals?
Phocidae
Name TWO human activities that contribute to ocean noise pollution.
answers include ships, tankers, sonar, oil exploration, construction, dredging
What order includes seals, sea lions, and walruses?
Carnivora
What structures expand in lunge-feeding whales?
Ventral grooves
What adaptation helps sea otters stay warm even though they lack blubber?
Extremely dense fur
Herring - swim in schools, higher in fat
Pollock - solitary, lower in fat, harder to digest
What can happen to cetaceans when intense sound causes confusion and disorientation?
Stranding
Name THREE characteristics shared by mammals.
Answers include hair, mammary glands, endothermy, lungs/air breathing, 4-chambered heart, large complex brain
What fatty structure helps focus outgoing sound waves during echolocation?
Melon
Why are polar bears highly dependent on sea ice?
They rely on sea ice to hunt seals
Explain why the western Steller sea lion population declined using evidence from the case study.
The western population declined because their diet shifted from high-fat herring to lower-fat pollock. Pollock provided less energy and were harder to digest, causing poor body condition, weight loss, lower pup survival, and population decline.
What are three purposes of whale songs?
Communication, reproduction/mating, feeding, staying with pod/group interaction