studyguide

The exam is on Monday of exam week at 1:30 in our usual room. It will focus primarily on the material from the last test. The test covers reproduction, social structure and life history patterns for marine mammals (chapters 13 and parts of 14). This test will be more like the first two in terms of the ratio of multiple choice/matching questions to short answer/essay.

Here are some study questions to get you thinking:

· According to theories on the evolution of mating strategies, how should male and female reproductive behavior differ, and why? Why do you think some birds mate for life and remain monogamous, while this behavior is never seen in marine mammals?

· How does the reproductive strategy and the length of the lactation period differ for phocids that breed on pack ice, fast ice, temperate land, and tropical land? Why?

· An imaginary species of pinniped is polygynous, with males following a female defense strategy. Females nurse their pups for 10 months and wean them gradually. What are your predictions for the rookery? (what type of habitat? what is the terrain like? Climate (seasonality)?). Justify each prediction with a clear explanation linking the environment to the behavior. Use examples of specific pinniped species to back up your statements.

· You have just discovered a large population of a new species of pinniped. It could be either a phocid or an otariid (naturally you recognized it at the time but for some reason you forgot--too much studying maybe??). However, you do remember a number of details about its habitat. It breeds each year on a single small isolated island with distinctly seasonal weather patterns (i.e. not tropical and not ice). The island is surrounded by sheer cliffs, except for a relatively small stretch (1-2 km) of accessible coastline. This coastline is uniform in shape, slope, and structure throughout its length. There are no terrestrial predators. No one has studied this population, but you believe that you can predict a number of behavioral characteristics, based on its habitat and studies of other species. For this new species, explain your predictions for:

a) Male behavior and sexual strategy on the breeding grounds

b) Duration of the pupping season (just a couple days? several weeks to a month? any time during the year?)

c) Female lactation strategy and milk content (you may want to take a guess at which family of pinnipeds this is)

· Once again, you find a new species of pinniped. This species breeds in the tropics, but the area experiences cold currents and a distinct seasonal upwelling period. Terrestrial predators are common, but there are a few small coastal stretches which are isolated from predators by rough terrain. Do you predict this species is monogamous or serially monogamous, or do you think it is polygenous? Explain your reasoning.

· Define delayed implantation, serial monogamy, socially mature, fission-fusion society. Know examples.

· Compare the strategies of reproductive competition between males for sperm whales, humpback whales, and right whales. How do they differ in terms of interactions with other male competitors in order to mate with females?

· What is a typical length of time for the lactation period in mysticetes, and why is this timing appropriate for migratory species, like grey whales and humpbacks? How does the length of the lactation period and degree of parental care in mysticetes compare to that of odontocetes? Why different?

· What are some typical differences in the reproductive patterns and parental care strategies for piscivorous vs. squid-eating odontocetes? Why might they be different?

· Milk content (% fat) varies among marine mammals. What range of % fat is observed in marine mammal families, and why some higher than others?

· What is a typical birthing interval (how many years between births) for females from each family of marine mammals, and what are the environmental and/or physiological constraints that dictate this timing?

· Describe the distributional, reproductive, and life history patterns for sea otters, manatees, and polar bears.

· Why are male sea otters able to sustain territories for many months, while male otariids are not?

· The various groups of marine mammals share many similar behaviors and life history traits. Despite these similarities, they have often evolved for very different reasons. For example, numerous species fast for certain periods each year, but often with very different motivations for doing so. Discuss the motivation for fasting (or not) in the species listed below. Which species do not fast and why? For those that do fast: When do they fast and for how long? Also, why do they fast? For each species, what is the benefit gained by not eating during the fasting period? Or, why is it not worthwhile to feed? Or, why are they unable to feed? Which sex fasts?

a) polar bear

b) otariid

c) Female Arctic ice-breeding seal (fasting patterns are similar for seals on fast ice and pack ice, although the duration and timing is different)

d) Humpback whale

e) Elephant seal

f) Bottlenose dolphin

g) Sea otter

h) manatee

TEST 3

This test will cover intelligence/communication/learning and feeding/ecology. In your book, this only includes part of chapter 11 and chapter 12 (and brains are covered in Chapter 7), so as you have probably noticed, there is fair bit of material from lecture that is not covered by your book. You may want to compare notes with some other students in class as a way of double-checking your material. Here are some study questions to help you focus:

Compare the brain structure of humans and dolphins. How do other marine mammal brains compare to that of a dolphin?
Define communication.
What are some examples of potential communication between marine mammals in the wild? How do you know it is communication?
Describe the structure of humpback whale song. What's so special about it – how is it unique among animal songs? Describe how it changes over time.
What is a song? What is it's purpose? Who sings besides humpbacks?
What is a dialect? How are orca dialects unusual?
Why might signature whistle patterns differ between male and female calves? What may signature whistles be used for?
What's the difference between animal communication and animal language? How good are dolphins and sea lions at language skills?
Do you think songs, dialects, and signature whistles are evidence of language? Defend your answer.
In studies of orcas, each pod has around 10 identifiable discreet calls that are used fairly regularly. Is this comparable in number to the size of the learned "vocabulary" in studies of captive odontocetes? What do you think is the potential for "language" among orcas in their natural environment? No right or wrong answer here, but justify your statements.
How does the sensory mode used (visual versus acoustic) impact learning abilities and memory in dolphins?
Humpack whale songs are unique among animal songs and orca dialects are unique among animal dialects. Define "song" and "dialect" as used in animal communication studies, and explain why the two examples above are unique.
If the biomass of killer whales near a seal rookery was about the same as the biomass of great white sharks in the same area, would you expect both species to have roughly equal impacts on the seal population (assuming both species feed primarily on seals in this area)? Why or Why not?
How are the feeding and digestive structures of various marine mammal groups adapted to their diet?
Give examples for the various diet categories and different feeding techniques depending on the prey.
Just how would you go about determining that 20% of the annual primary production in the Gulf of Maine is required to support cetaceans? Or that whales account for 36% of the fish predation along the NE coast of the US? (This is not a details question – I just want you to think through a potential approach to the problem.)
Give different examples of a marine mammal that (1) functions as a keystone predator in its community, (2) has a strong top-down impact on it's community but not really "keystone," and (3) has minimal top-down control on community structure.
We talked about a number of studies in which marine mammals consumed a large proportion of the fish population or were supported by a high percentage of the annual primary production for a region of the ocean. Most of these regions were fairly productive areas. Would you expect that in much less productive regions of the ocean, the proportion of resources going to marine mammals would be even higher? Why or why not?
While conducting an energetics study on a baleen whale, you determine that an individual whale of a given size filters 100,000 m3 of water/day. For simplicity's sake, assume that the baleen filters the water with 100% efficiency. The average energy content of prey in the water is 5 kcal/m3, and you estimate the metabolic requirements of the whale at 200,000 kcal/day. By these numbers, is the amount of prey in the water enough to support the energetic demands of the whale?

TEST 2

This test will cover thermoregulation, osmoregulation, diving adaptations, and sensory systems. This jumps around in your book a bit, but you can see which chapters and portions of chapters are covered. The questions below should be helpful. Some may be repetitive, but that’s OK if you review something twice. As usual, you should be able to interpret any figures in the book for these sections.

List and describe the various physiological adaptations important for thermoregulation in marine mammals. Describe and explain the function of any specialized structures wherever appropriate, and discuss specific areas of the body that require more specialized adaptations for either warming or cooling.
How does the structure of the marine mammal countercurrent heat exchange system enable both warming and cooling depending on the conditions? Give specific detailed examples of what happens in each case.
You are analyzing data from a satellite tag which is recording the dive patterns and heart rate of a northern elephant seal off California. During long surface intervals the pulse is about 60 beats per minute, and during dives it generally decreases to less than 10. After one dive (lets call it Dive A), you notice the pulse goes up to 100, but after a different dive (Dive B), the pulse goes up to over 150. What do you think was different about these two dives, and how do you know?
List and explain the various physiological adaptations that enable many marine mammals to dive to great depths for long periods of time. Specifically, how do they deal with (1) oxygen issues and (2) problems associated with increased pressure?
List and describe the circulatory adaptations (structure and/or behavior of the heart, blood vessels, and circulation patterns) which enable marine mammals to make long dives.
List and describe the various physiological and behavioral adaptations important for osmoregulation in marine mammals. Describe and explain the function of any specialized structures or behaviors wherever appropriate.
Give an example of a marine mammal whose normal metabolic rate is (a) unusually high, and (b) unusually low. Why?
Consider the circulatory mechanisms of the dive response and of thermoregulatory adaptations in a dolphin, and how they may compliment or conflict with one another. With this in mind, answer the following: can a spinner dolphin at the equator dive for a longer period in the warm surface waters or in deeper cool waters. Justify your answer.
Describe an example where a network of vessels or retia is used for (a) thermoregulatory cooling, and (b) pressure regulation during deep dives
A 250 pound human and a 250 pound dolphin both store about 41% of their oxygen reserves in their blood. Does that mean they are storing the same amount of oxygen in their blood? Explain briefly.
Marine mammals do have a greater buffering capacity in their blood than most terrestrial mammals, but that is not the whole story. What is another reason that marine mammals are more tolerant to the build-up of lactic acid in their muscle tissues during anaerobic dives?
What are 3 purposes for blubber?
Other than their efficient kidneys, how can marine mammals obtain additional water, limit the loss of body water, and utilize stored water during fasting periods?
Unlike terrestrial vertebrates, marine mammals have good vision both below and above water. Compare the structure of the eye for marine mammals and terrestrial mammals, including how each functions in both air and water.
If the human iris was capable of making a pinhole-sized pupil, would we be able to see more clearly underwater? Explain your reasoning clearly. Consider both the abilities of the eye and the physical limitations of the underwater environment.
Would you expect to record odontocete echolocation clicks with a faster click repetition rate (getting closer together) in conjunction with a decrease in the peak frequency of the clicks (lower frequencies)? Why or why not?
Explain how and why bone conduction works so well for dolphin hearing underwater, but not so well for human hearing. How do dolphins hear sounds in air?
Compare the structure of the ears and associated hearing structures for odontocetes, mysticetes, and pinnipeds, and their relative hearing abilities both in air and underwater.
What are the potential uses of sounds made by marine mammals? Which groups use sounds for which purposes?
List and describe the basic components of Ken Norris' theory for the mechanism of echolocation and hearing in odontocetes. List several pieces of evidence which support his ideas. What is some evidence that does not support it, or at least suggests there is more that we don't know?
In sea water, a marine mammal tends to gain ______ and lose _______ (this is an osmoregulation question, so something like “knowledge” and “teeth” are not the kind of answers I’m after). Do they do so at a similar rate to a fish/marine invert? Explain.
Everyone knows that we can’t drink only seawater and survive. Why is that?
How are marine mammal kidneys different than ours? Are they similar for all groups of marine mammals?
Where do marine mammals get most of their water? Does the kind of prey they eat have an effect?
What is metabolic water? When is it particularly useful?
Other than the kidneys, how do marine mammals limit water loss?

TEST 1

The test is on chapters 1-5,8, lectures, and supporting material from lab (I will not ask you to do a force diagram!)
What are the 3 orders of extant marine mammals? What is the only extinct order of marine mammal?
What are the suborders/families for (insert any marine mammal order)? What are their common names, if they have one?
What are the pinniped sub-families and who do they include? For each, are they probably monophyletic?

· Briefly list the defining characteristics for each of the marine mammal families: (insert any family we have discussed).

· Alternative wording: A cetacean with 1-2 pair of teeth in the lower jaw and a V-shaped throat groove would be a member of which family? (substitute any description for a given family, etc.)

· Or, a second alternative: the above may be in the form of a matching question where you are given a list of family names (or orders, or whatever) to match to such clues as "baleen and only 2 throat grooves" or "family contains only 1 species," etc.

· You don't have to memorize how many species belong to each order or family, etc., but you should be aware of general trends, such as which family is the most numerous or which is only 1 or a few species.

What global events may have provided favorable conditions for the evolution of (insert group here: cetaceans, pinnipeds)? Be explicit and complete.
List approximate dates for Otariids and Phocids spreading into the southern hemisphere. What global event likely facilitated this move (especially for Otariids)?

· Describe the biogeography of extant pinniped/cetacean/sirenian families.

· What taxonomic level is "delphinidae?" (insert any example of a phylum, class, order, sub-order, family)?

· Alternative wording: To what phylum (or class, order, sub-order, family) does a California sea lion belong?

· Starting at the K-T Boundary, construct a timeline listing the major events in the evolution of marine mammals, including times and locations for the evolution of cetaceans, sirenians, pinnipeds, sea otters, polar bears, and the only extinct order of marine mammals (don’t forget to give me the name of that order). Indicate and explain the major global events (oceanographic, climatological, and other) that likely contributed to the rise of these groups.

· Without having to memorize all the opposing scenarios, you should understand cladograms enough that if I ask you to draw a cladogram depicting a specific relationship (for example, demonstrating that of the 3 pinniped families, odobenids are monophyletic with phocids only), you are able to do it.

· List and describe the important "players" discussed in class that fall along the evolutionary line of cetaceans, from the early terrestrial ancestors (broad group and potential specific group) to the rise of the 2 extant sub-orders, to modern cetaceans. Describe how they differed and give an approximate time frame for each. For the modern extant cetaceans, indicate at least 2 early families and 2 fairly recent families.

· List and describe the important "players" discussed in class that fall along the evolutionary line of pinnipeds, from the early terrestrial ancestors (broad group) to the rise of the 3 modern families. Give an approximate time frame for each, and briefly describe where they started and how they spread into other regions of the globe.

· What is "telescoping" of the skull?

· How does an archaeocete differ from an odontocete?

· Who are the closest living relatives of sirenians (general group and at least 1 specific example)? Give a (very) general timeline for the development of the order, from the earliest amphibious mammals in the line to the development of the 2 modern families.

· When and where did sea otters evolve? How do they differ from river otters?

· When and from whom did polar bears evolve?

· Define: cladistics, parsimony, phylogeny

· Can you describe hydrodynamic adaptations and relationships using terms like fineness ratio, Reynold’s number, power and drag, cost of transport… What forces are most important in determining hydrodynamic efficiency?

· Give 3 different examples of a skeletal adaptation for a specific marine mammal group that enhances its swimming power. Explain.

· Give 4 examples of hydrodynamic adaptations to the general shape of marine mammals.

· Do you know: Phocinae, Monachinae, Otariinae, Arctocephalinae, Mesonychian condylarth, archaeocetes, Basilosauridae, latrine, Pakicetidae, Ambulocetidae?

· Major Taxonomic Groups

Phylum Chordata

Class Mammalia

3 Orders:

1. Order Cetacea (2 suborders)

a. SubOrder Mysticeti (~12 species)

b. SubOrder Odontoceti (~71 species)

2. Order Sirenia (2 families)

a. Trichechidae (3 species)

b. Dugongidae (1 extant species, 1 recently excinct)

3. Order Carnivora

Suborder Pinnipedia ("feather" or "wing-footed" – formerly considered an Order of its own, but now most commonly considered a Suborder of Carnivora)

a. Family Phocidae - true or earless seals (~18 spp.)

b. Family Otariidae - eared seals (sea lions/fur seals - ~16 spp.)

c. Family Odobenidae - walrus

2 other carnivore families

a. Family Mustelidae - sea otters (2 species)

b. Family Ursidae - polar bear

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