Marine Mammals & Birds

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Marine Mammals Birds
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• Return to the Oceans
• Mammals have returned to the oceans multiple
  times
• Adaptations
• vivipary
• suckling young
• thermoregulation
• feeding
• diving
• osmoregulation
• Well look at adaptation in marine mammals from
  the least to the most

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• Adaptations for diving
• Exchange a large amount of air on each breath
• Up to 90 in each breath (humans exchange about
  20)
• Blood with more oxygen carrying capacity
• Heart rate slows
• Blood flow shunted
• Higher concentration of myoglobin in the muscles
• Collapsing lungs
• Dive with no air in contact with blood vessels to
  avoid problems of nitrogen being forced in

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Fusiform Shape and Streamlining Evolutionary
Convergence
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• Two basic bioenergetic strategies used by animals
  
• Endothermy warm blooded
• Ectothermy cold blooded

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Thermoregulation
Concurrent exchange
Countercurrent exchange
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Marine Birds
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Salt Excretion in Birds
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• Penguins
• 17 species found in southern hemisphere
• Spends 75 of lifetime in water

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• Penguin Adaptations
• Heavy, solid bones for diving
• Watertight feathers (up to 70 per sq. in.)
• Blubber for insulation
• Oil gland for coating feathers
• Black white counter shading
• Deep divers
• - 500 m, 15 min.
• Paddle-like feet
• Streamline, fusiform body
• - 15 mph
• Social

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Altruism
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Nesting
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Nests on pack ice
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Rookery

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Marine Mammals
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Marine mammals

• Characteristics of marine mammals
• Warm-blooded
• Breathe air
• Have hair (or fur)
• Bear live young
• Females have mammary glands that produce milk for
  their young

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Marine mammals Order Sirenia

• Sirenian characteristics
• Large body size
• Sparse hair all over body
• Vegetarians
• Toenails (on manatees only)
• Includes
• Manatees
• Dugongs

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Manatee Dugong

• Most complete transition to marine life along
  with whales and dolphins
• Related to the elephant, but common ancestor
  didnt look like either of them
• Once many more species around
• Large layer of blubber
• Origin of the mermaid myth
• Herbivores
• Nostrils on top of snout have valves to keep
  water out
• Both species have one calf at a time
• Tend to have a single calf every 3 years

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Dugong

• Location coastal and inland waters of the
  western Indo-Pacific region
• Dugongs are exclusively marine and have a
  dolphin-like tail
• Dugongs tend to dig seagrass rhizomes
• Predator includes tiger sharks

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10,000
Dugong Range
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Family Dugongidae
Dugong dugong
Steller's Sea CowtHydrodamalis gigas Discovered
1741, extinct 1768.
8.9 ft, 551-661lbs
30ft, 4.4 tons
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Manatee

• Location Florida, Central and South America
• Manatees have paddle-like tails and frequent
  freshwater
• Manatees tend to crop and grab with prehensile
  lips
• Manatees are larger than dugongs
• Few predators
• Threats
• Careless boaters
• Habitat loss

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Manatee
9.8 ft, 800-1200lbs
3,000 in U.S.
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Relationship between Sirenians and elephants
(mtDNA)
Asian elephant
African elephant
tmammoth
tmastadon
tStellars sea cow
Dugong
Ancestral mammals
West Indian manatee
Brazilian manatee
West African manatee
Other mammals
80
60
40
20
0
Million of years before present
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Marine mammals Order Carnivora

• All members of order Carnivora have prominent
  canine teeth
• Includes
• Sea otters
• Polar bears
• Pinnipeds (flipper-footed)
• Walrus
• Seals
• Sea lions/fur seals

Hawaiian Monk Seal
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Sea Otter
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Sea Otter

• Enhydra lutris
• Native to north Pacific
• 394,000 hairs/cm2
• No blubber
• Female 45 lbs Male 65lbs
• Diet Sea urchins, abalone, mussels, clams,
  crabs, snails and about 40 other marine species.

• Uses tools
• Dives to 330 ft
• Rests in coastal kelp forests

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Polar Bear
Pop size 22,000 to 27,000 Weight 550 to 1,700
pounds
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Polar Bear

• Ursa maritimus
• United States, Canada, Russia, Greenland and on
  the Arctic islands of Norway
• Male 10 feet tall and weigh over 1400 lbs
• Female seven feet and weigh 650 lbs
• wild polar bears live up to age 25.

• Good swimmers
• Thick blubber
• Thick fur

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• Polar bears
• Polar bears are the least adapted to the marine
  lifestyle
• Land animals that are adapted to the cold

• Considered marine mammals because they feed
  almost exclusively on marine organisms
• Very good swimmers, but cant dive below surface
  well
• Hunt seals and walruses, occasionally cetaceans

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• Range
• Circumpolar in Arctic
• Range depends on sea ice

• normal range          occasional range over
  pack occasional range over permanent ice

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Pinnipeds
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Pinnipeds
Hawaiian Monk Seal
Family Phocidae
Walrus
Sea Lion
Family Odobenidae
Family Otariidae
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Biology and Natural History

• Order Pinniped (seals, sea lions, walruses)
• Family Phocidae- true, earless seals
• Family Otariidae- eared seals and sea lions
• Family Odobenidae- walruses
• 34 known species
• Evolved 20 mya from Order Carnivora (ancestors of
  dogs and bears)
• Differ in possession of external ears and mode of
  locomotion

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Differences between seals and sea lions/fur seals
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Hawaiian Monk Seal
Family Phocidae

• Lack external ears
• Hind flippers propel them while swimming
• Front flippers act as rudders
• Travel on land is difficult (wiggle)

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Sea Lion
Family Otariidae

• Eared seals
• Front flippers propel animal when swimming
• Rear flippers act as rudders
• Fairly mobile on land

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Walrus
Family Odobenidae

• Found in Arctic region
• Lack external ears
• Paddle with front flippers
• Rear flippers act as a rudder
• Fairly mobile on land

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Walrus Range Map
Pacific walrus is in lavender, Atlantic walrus is
in rose.
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Walrus Facts

• Location
• Bering sea, Pacific Ocean, Atlantic Ocean, Arctic
  Ocean
• Pop Size
• 250,000
• Size
• Weight 2,000-3,500 lb.
• Breeding
• Sexually mature late
• females, usually 6-7 years
• males, 15 years.
• Produce few offspring

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Walrus Facts

• Lifestyle
• Habit Gregarious, living mainly in herds.
• Diet Benthic suction feeders. Feed mainly on
  bivalve mollusks, but also other invertebrate
  marine animals, fish, sometimes seals and whales.
• Predators polar bears, killer whales, and humans
  
• Lifespan Up to 40 years.

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Walrus Facts

• Swim speed 7-35 kph
• Tusks
• Both male female
• Used for dragging body across land or ice
• Symbolize age, sex, and social status
• Pharyngeal pockets
• 2 found on either side of the esophagus that hold
  up to 50 liters of air ).
• For buoyancy these pockets facilitate sleep in
  the water in an upright position
• May be used to amplify mating calls

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Whales, Dolphins, Porpoise
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Pakicetus attocki
Age Early Eocene, 50 million years old Location
Pakistan
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Whale Evolution
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Ambulocetus natans in action. A reconstruction of
an early close cousin of whales.
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Marine mammals Order Cetacea
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Marine mammals Order Cetacea

• Cetacean characteristics
• Blowholes on top of skull
• Skull telescoped (streamlined shape)
• Very few hairs
• Includes
• Whales, dolphins, and porpoises

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Two suborders of order Cetacea
(55 mya- entered sea)

• Suborder Odontoceti (toothed whales)
• Echolocate (send sound through water)
• Includes killer whale, sperm whale, dolphins,
  porpoises, and many others
• Suborder Mysticeti (baleen whales)
• Have rows of baleen plates instead of teeth
• Includes blue whale, finback whale, humpback
  whale, gray whale, and many others

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Differences between dolphins and porpoises

• Dolphins have
• An elongated snout (rostrum)
• A sickle-shaped (falcate) dorsal fin
• Conical-shaped teeth

Killer whale jawbone
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Differences between dolphins and porpoises

• Porpoises have
• A blunt snout (rostrum)
• A triangle-shaped dorsal fin
• Spade-shaped teeth

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• Echolocation
• Sensing environment
• Produce clicks that travel out, hit objects and
  reflect back
• Produced by a structure in the airway called the
  monkey lips
• Sound received through the lower jaw
• Low frequency clicks travel further but can only
  be used for big objects
• High frequency clicks can discriminate small
  objects but dont travel as far

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Deepest Diver
(3km1.5 miles)
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Mysticeti The baleen whales

• Mysticeti whales have baleen instead of teeth
• Baleen plates
• Hang as parallel rows from the upper jaw
• Are made of keratin
• Are used as a strainer to capture zooplankton
• Allows baleen whales to eat krill and small fish
  by the ton

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Baleen
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Types of baleen whales

• Baleen whales include three families
• Gray whale (a bottom-feeder with short baleen)
• Rorqual whales (medium-sized baleen)
• Balaenopterids (blue whales, finback whales, and
  other large whales )
• Megapterids (humpback whales)
• Right whales (surface skimmers with long baleen)

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Whale Migration
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Whale Carcass Removal
http//perp.com/whale/video.nc.html
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• What characteristics distinguishes the three
  groups of pinnipeds?
• Why do whales migrate to Hawaii?
• What is echolocation?
• Which marine mammals lack blubber?
• Why are penguins black and white?
• What is the difference between an odontocete and
  mysticete?
• Why dont whales get the bends?
• Why shouldnt you load a dead whale with
  dynamite?