quiz 4 Flashcards
What are the characteristics that define a mammal
- hair or fur (reduced in some marine mammals)
- endothermic
- mammary glands
- uterine gestation
- lungs
- 4 chambered hearts
What do marine mammals use blubber for
insulation; warmth, food reserves
what do sea otters eat
mollusks, crustaceans, and echinoderms (sea starts and urchins)
why is climate change/sea ice melting an issue for marine mammals like polar bears?
- polar bears are forced to search on land
- many pinnipeds breed on pack ice
- many species use ice as a refuge when hunting
- walruses are especially vulnerable because they cannot stay in deep water for long
- food resources are changing
What aspects of marine mammal behavior and reproduction makes them susceptible to human influence?
What is convergent evolution?
the process by which unrelated species evolve similar physical characteristics because they have similar lifestyles
how do baleen whales use their baleen to feed
rows of flexible plates hang down from the upper jaws; the inner edge of each plate consists of hair-like bristles that overlap and form a dense mat
what is baleen made of
keratin
why were whales hunted historically
commercially hunted for their meat and blubber which was processed into fuel, soaps, and other products
how do toothed whales use their teeth
only to catch and hold prey, not to chew it
how many blowholes do toothed whales have
just one
differences between dolphins and porpoises
porpoises - blunt nosed, flattened teeth
dolphins - distinctive snout, conical teeth
how do toothed whales use echolocation
emit sound waves, listen for the echoes reflected back from surrounding objects, brain analyzes the echoes
(the time it takes the echoes to return tells the animal how far away the object is)
how to toothed whales use vocalizations
to communicate to feed, reproduce, or play
sounds can be pod-specific, different sounds associated with different moods
what is cooperative feeding
when two or more individuals effectively capture more and/or bigger prey
examples of how whales engage in cooperative feeding
humpback whales - bubble net feeding
how do marine reptiles breathe and where do they reproduce
breathe air using lungs and most reproduce on land
what are some threats to cetaceans
- noise pollution
- entanglements and drownings (fishing gear)
- boat strikes
why can’t marine reptiles live in the cold?
reptiles are cold-blooded, so limited to warmer temp regions
how do reptiles deal with ridding themselves of excess salt
osmoregulation, special salt glands
in what ways are sea turtles adapted to living in the sea
They developed Paddle-shaped forelimbs, wing-like swimming, non-retractile head and limbs, completely roofed skull, backbone fused to shell (except leatherback), streamlined body, good sense of smell, good vision, salt glands near eyes, slow metabolic rate, long lifespan, return to land to lay eggs
what is the sea turtle nesting process
migrate to home beach, dig hole, lay eggs, eggs hatch, turtles find
ocean and hope to survive
How is sex determined in sea turtles
The temperature in which they are burrowed in, Cold and wet= male, hot and dry = female
why are sea turtles threatened by climate change