exam 2

Question 1

specialist

Answer 1

eats one type of prey/species
e.g. crabeater seals

Question 2

generalist

Answer 2

easts various prey/species
e.g. otters

Question 3

otter diet and foraging

Answer 3

diet: sessile, slow moving inverts (sea urchins, clams, oysters, etc)

foraging: use vision and front paws to collect/manipulate prey, employs tools to open shells (rocks)

Question 4

3 species of pinnipeds that do not follow traditional foraging and why are they an anomaly

Answer 4

1. leopard seals - penguins and other seals
2. crabeater seals - specialized euphausiid forager
3. walrus - benthic forager on slow/immobile prey

anomaly because normal diet = fish, squid, fast prey items & generalists

Question 5

mysticete diet and foraging

Answer 5

diet: plankton, small schooling fish

foraging: consume whole schools/patches of prey

Question 6

three mysticete foraging strategies

Answer 6

1. lunging
2. bottom feeding
3. skim feeding

Question 7

mysticete foraging: lunging

Answer 7

e.g. humpback whales

take huge mouthfuls of water and strain prey from it

Question 8

mysticete foraging: bottom feeding

Answer 8

e.g. gray whales

take mouthfuls of liquified mud and strain prey from it

Question 9

mysticete foraging: skim feeding

Answer 9

e.g. bowhead whales

slowly swim through water and letting prey collect in baleen plates & then lick it off

Question 10

odontocete prey

Answer 10

fish, squid, shrimp (fast moving species)

Question 11

echolocation’s role in foraging

Answer 11

use echolocation to detect fish burrowed in sand or in low visibility

Question 12

odontocete foraging: fish whacking

Answer 12

launch fish into air with flukes - stuns/kills fish

Question 13

odontocete foraging: strand feeding

Answer 13

intentionally strand on beach to pursue prey - push them onto shore to corral and catch them

Question 14

spatial variability in foraging

Answer 14

prey destiny/types vary by location

Question 15

temporal variability in foraging

Answer 15

prey density/types vary by season

Question 16

optimal foraging theory

Answer 16

adopt a foraging strategy that maximizes benefits for the least cost to maximize biological fitness

Question 17

optimal foraging theory example: harbor porpoises

Answer 17

avoid less profitable prey (small flounder) and favor more profitable prey (large flounder)

flounder are hard to locate and catch so if you are going to put in the work to catch one it is optimal to catch a large one

Question 18

sperm whale foraging movement

Answer 18

poor feeding conditions: straight line travel (appear to attempt to change locations)

good feeding conditions: zig-zag travel (appear to attempt to stay in same spot)

Question 19

trophic cascade

Answer 19

significant change in the population size of a species at one trophic level effects all of those below them in an ecosystem

Question 20

trophic cascade example: sea otters

Answer 20

reduction in sea otters = increase in sea urchins = reduction of kelp

Question 21

how to study life history traits

Answer 21

1. follow individuals through lifespan
2. cohort studies

Question 22

life history traits

Answer 22

1. lifespan
2. sexual maturity
3. gestation period
4. litter size
5. inter birth interval
6. lifetime reproduction
7. mating strategies

Question 23

three pinniped mating strategies

Answer 23

1. terrestrial birth and mating
2. terrestrial birth, aquatic mating
3. ice birth, ice/aquatic mating

Question 24

pinniped mating strategy: terrestrial birth and mating

Answer 24

females clumped by defensible males on remote islands

males defend resources/territory - females choose males based on resources/territory

high polygyny

Question 25

pinniped mating strategy: terrestrial birth, aquatic mating

Answer 25

females clumped together in water - males display on beaches and females choose who to mate with low to moderate polygyny

Question 26

pinniped mating strategy: ice birth, ice/aquatic mating

Answer 26

females not clumped, males defend single female serial monogamy

Question 27

elephant seal mating strategy

Answer 27

large dominant males control female harems (very few) - mate with up to 100 females in a season (mate for only one season then die) many males delay mating or have NO offspring ever results in lack of genetic variation as most pups come from the same few fathers

Question 28

delayed implantation

Answer 28

fertilized egg waits to implant in uterine wall until sufficient fat stores to support pregnancy

Question 29

induced ovulation

Answer 29

won't release egg until mating has occurred

Question 30

how does delayed implantation and induced ovulation help polar bears?

Answer 30

1. prevents loss of mating opportunity 2. may not ovulate with sub-optimal mates (avoid sub-optimal genes)

Question 31

litter size and parental care of otters

Answer 31

litter: 1 parental care: high maternal care for ~1 yr (sea otter moms take pup everywhere with them)

Question 32

general life history traits of cetaceans

Answer 32

lifespan: variable (13-200+ yrs) sexual maturity: average of 5-7 yrs gestation period: average of 12 months litter size: 1 inter birth interval: some annual while others 3-5 yrs

Question 33

mate guarding

Answer 33

guard and mate with 1 (maybe 2) females e.g. indo-pacific bottlenose dolphins in shark bay: 2 males with keep ("kidnap") a female with them for a long period of time so only they can mate with her

Question 34

laryngeal sound production

Answer 34

sound produced through vocal chords in throat (like us)

Question 35

dialect

Answer 35

variation of vocalization that is unique to a specific region/group - usually requires potential for genetic exchange

Question 36

vocal learning

Answer 36

modification of vocalizations as a result of mimicking other individuals

Question 37

dialect example: elephant seals

Answer 37

adult male threat vocalizations at the Ann Nuevo rookery have a slower pulse rate than those at other rookeries

Question 38

vocal learning example: killer whales in British Columbia/Washington

Answer 38

high proportion of shared calls in each pod decreasing acoustic similarities with decreasing relatedness

Question 39

mysticete acoustic communication frequency

Answer 39

very low frequency sounds have to travel long distances and deep sounds go further than high ones

Question 40

whale songs

Answer 40

repeated acoustic elements, found in several species

Question 41

vocal learning in blue whale songs

Answer 41

9 stable, regional dialects observed across the different populations

Question 42

odontocete acoustic communication range

Answer 42

- high ultrasonic hearing - sounds average of 20,000 to 120,000 Hz - also have low band narrow frequency sounds (LNF) that are 500-1000 Hz

Question 43

how do odontocetes produce sound?

Answer 43

MLDB complex in nasal passages (monkey lips dorsal bursae)

Question 44

odontocete whistle

Answer 44

- Most odontocete species - Mostly 2,000 – 20,000 Hz - Used for communication - Highly variable

Question 45

signature whistle

Answer 45

learned, individually distinctive whistle types that are suggested to communicate ID info by whistler

Question 46

signature whistle study: dolphins plus

Answer 46

seen that mothers will use their signature whistle to call their calves back to them

Question 47

gillnet

Answer 47

walls of monofilament netting that hang in the water column (drifting or stationary)

Question 48

gillnets as a threat to marine mammals

Answer 48

- non-discriminate = massive bycatch of marine mammals - hard to detect with echolocation/vision - do not biodegrade

Question 49

gillnet impact of the vaquita

Answer 49

high mortality rates due to gillnets set for illegal fishing of critically endangered totoaba

Question 50

impacts of the deepwater horizon oil spill on marine mammals

Answer 50

- chemicals found in many species - associated with multiple standings - stillborn dolphin calves (10x more than normal) - up to 50% of dolphins dies/seriously ill