marine mammals & birds 009b. phylum chordata subphylum vertebrata class reptilia class aves...

Marine Mammals & Birds

009b

Phylum ChordataSubphylum Vertebrata

• Class Reptilia• Class Aves (birds)• Class Mammalia

Class Aves

Birds

http://www.phyletisches-museum.uni-jena.de/images/archaeopteryx_berlin_1864.jpg

Evolution

http://www.zoology.ubc.ca/~bio336/Bio336/Lectures/Lecture5/dinobird.jpg

Class AvesClass Aves

Characteristics

• Warm blooded• Feathers and wings• Hollow bones• Horny bill• Lungs have air sacks• Hard egg shell

Marine Birds

• Only 3% of all bird species• Evolved from different

groups of land birds• Spend significant part of

life at sea• Feed on marine organisms

Marine Birds

• Must nest on land

Marine Birds

• Salt secreting glands

• Webbed feet for swimming (not all)

Marine Birds

• Dense waterproof plumage (except commorants and some terns)

Marine Birds

• Migrations (not all)• Arctic tern -

24,000 mi roundtrip between Arctic and Antarctica

• Sooty shearwaters - 40,000 mi/yr

Penguins:

• 17 species found in southern hemisphere• Spends 75% of lifetime in water

Fairy (aka Little blue) penguins – up to 16 in

(recovering from oil spill)Emperor penguins - up to 45 in

• Southern hemisphere only (Galapagos south to Antarctica)

Penguins

• 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

Penguin Adaptations

• Don’t fly in air, but swim very well (fly through the water)

• Wings act as flippers

Adelie penguins

King penguin

Emperor penguins

Penguin Adaptations

• Eyes better adapted for underwater vision than air

• Adapted for colder waters and air temps

Black-footed penguin (aka African, Jackass)Gentoo penguin

Penguin Adaptations

• Larger penguins eat fish, squid

• Smaller eat large plankton (krill)

• Mostly feed near surface

• Some dive to 1800+ ft, 22 minsGalapagos penguin

Penguin Prey

Magellanic penguins

King penguin

Gentoo penguin

Penguin Nesting

Penguins

Rockhopper penguin

Macaroni penguins

Yellow eyed penguins

Altruism

Nests on pack ice

Rookery

Marine Birds Tubenoses

• Albatrosses, shearwaters, and petrels

Albatross – longest wingspan

ShearwaterStorm petrel

Marine Birds

Pelicans and web-footed birds Cormorants, frigates, gannets

Brown pelican

Cormorant

NOAA

NOAA

GannetFrigate

Marine Birds

Gulls• Jaegers/skuas, terns, puffins,

razorbills

Herring gull

Horned puffinLeast tern

Marine Birds

Feeding strategies

Marine Birds

Beak shapes:

Marine Birds

Shorebirds – beak length

Marine BirdsShorebirds•Sandpipers, plovers, coots

Sandpiper

Hawaiian coot

Godwit

Pacific Golden Plovers

Marine Birds Shorebirds

• Herons, egrets

Great blue heron Black-crowned night heron Great egret

Marine BirdsShorebirds

• Swans, geese, loons • Ducks, coots, grebes, mergansers

Mute swans

Common merganser

Wood duck

Marine Birds

Birds of prey• Eagles, ospreys

Human Impacts

• Pollution – pesticides, PCBs, metals

Bioaccumulation,biomagnification

Class MammaliaClass Mammalia

Dugong

manatee

Sea otter

Whales & Dolphins

Polar bear

Seals & sealions

Return to the Oceans Mammals have returned to the oceans

multiple times

Adaptations• vivipary• suckling young• thermoregulation • feeding• diving• osmoregulation

We’ll look at adaptation in marine mammals from the least to the most

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

Fusiform Shape and StreamliningEvolutionary Convergence

Two basic bioenergetic strategies used by animals :

• Endothermy “warm blooded”

• Ectothermy “cold blooded”

Thermoregulation

Concurrent exchange

Countercurrent exchange

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

Marine mammals: Order Sirenia

• Sirenian characteristics:– Large body size– Sparse hair all over body– Vegetarians– Toenails (on manatees only)

• Includes:– Manatees– Dugongs

Manatee & DugongManatee & Dugong• Most complete transition to marine life

along with whales and dolphins • Related to the elephant, but common

ancestor didn’t 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

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

Dugong

Dugong Range

10,000

Family Dugongidae

Dugong dugong Steller's Sea CowtHydrodamalis gigasDiscovered 1741, extinct 1768.

8.9 ft, 551-661lbs

30ft, 4.4 tons

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

Manatee

Manatee

9.8 ft, 800-1200lbs3,000 in U.S.

Million of years before present

80 60 40 20 0

Ancestral mammals

Asian elephant

African elephant

tmammoth

tmastadon

Dugong

tStellar’s sea cow

West Indian manatee

Brazilian manateeWest African manatee

Other mammals

Relationship between Sirenians and elephants (mtDNA)

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

Sea OtterSea Otter

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

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

Polar BearPolar Bear

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

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 can’t dive below surface well

• Hunt seals and walruses, occasionally cetaceans

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

• normal range          occasional range over pack

occasional range over permanent ice

PinnipedsPinnipeds

Sea LionWalrus

Family Phocidae

Family OtariidaeFamily Odobenidae

Hawaiian Monk Seal

Pinnipeds

Order Pinniped (seals, sea lions, & walruses)Family Phocidae- true, earless sealsFamily Otariidae- eared seals and sea lionsFamily 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

Biology and Natural History

Differences between seals and sea lions/fur seals

Family Phocidae

Hawaiian Monk Seal

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

Sea LionFamily Otariidae

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

Walrus

Family Odobenidae

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

                     Pacific walrus is in lavender, Atlantic walrus is in rose.

Walrus Range Map

Walrus FactsLocation: • 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

Walrus FactsLifestyle

• 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.

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

Whales, Dolphins, Whales, Dolphins, & Porpoise& Porpoise

Age: Early Eocene, 50 million years oldLocation: Pakistan

Pakicetus attocki

Whale Evolution

Ambulocetus natans in action. A reconstruction of an early close cousin of whales.

Marine mammals: Order Cetacea

Marine mammals: Order Cetacea

• Cetacean characteristics:– Blowholes on top of skull– Skull telescoped (streamlined shape)– Very few hairs

• Includes:– Whales, dolphins, and porpoises

Two suborders of order Cetacea

• 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

(55 mya- entered sea)

Differences between dolphins and porpoises

• Dolphins have:– An elongated snout

(rostrum)– A sickle-shaped

(falcate) dorsal fin– Conical-shaped

teeth Killer whale jawbone

Differences between dolphins and porpoises

• Porpoises have:– A blunt snout

(rostrum)– A triangle-shaped

dorsal fin– Spade-shaped teeth

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 don’t travel as far

Deepest Diver

(3km~1.5 miles)

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

Baleen

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)

Whale Migration

Whale Carcass Removal

http://perp.com/whale/video.nc.html

1. What characteristics distinguishes the three groups of pinnipeds?

2. Why do whales migrate to Hawaii?3. What is echolocation?4. Which marine mammals lack blubber?5. Why are penguins black and white?6. What is the difference between an

odontocete and mysticete? 7. Why don’t whales get the bends?8. Why shouldn’t you load a dead whale

with dynamite?

Inquiry