Marine Mammals, Birds

and Reptiles

Marine Mammals, Birds

and Reptiles

To the Land and BackTo the Land and Back

350 MYA - Tetrapods evolve from fish Need:

Lungs Forelimbs Ability to avoid drying out

Some move back to the oceans - new adaptations required

350 MYA - Tetrapods evolve from fish Need:

Lungs Forelimbs Ability to avoid drying out

Some move back to the oceans - new adaptations required

Sea TurtlesSea Turtles

Enclosed by carapace Cannot retract head Flippers Return to land to

reproduce after long migrations

All threatened to endangered

Enclosed by carapace Cannot retract head Flippers Return to land to

reproduce after long migrations

All threatened to endangered

Sea SnakesSea Snakes

Sea SnakesSea Snakes Tropical Indian and

Pacific Laterally compressed Ovoviparous Small mouth but

highly venomous

Tropical Indian and Pacific

Laterally compressed Ovoviparous Small mouth but

highly venomous

Marine IguanasMarine Iguanas

Marine IguanasMarine Iguanas

Galapagos Live in large

colonies Herbivores Salt glands in

nose

Galapagos Live in large

colonies Herbivores Salt glands in

nose

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Saltwater CrocodileSaltwater Crocodile

Very large (usually max of 20 ft.)

Usually found in coastal areas

Highly aggressive

Very large (usually max of 20 ft.)

Usually found in coastal areas

Highly aggressive

SeabirdsSeabirds Homeothermic /

Endothermic Oil glands Feathers Light, hollow

bones Hard egg shell

Homeothermic / Endothermic

Oil glands Feathers Light, hollow

bones Hard egg shell

But can they do this??!!

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PenguinsPenguins

Flightless Denser bones (reduces

buoyancy) Layer of fat plus

feathers for warmth Southern hemisphere Mating practices

Flightless Denser bones (reduces

buoyancy) Layer of fat plus

feathers for warmth Southern hemisphere Mating practices

TubenosesTubenoses

TubenosesTubenoses

Heavy curved beak Mostly open sea

predators Elaborate courtship

followed by lifelong pairing

Albatrosses, shearwaters, petrels

Heavy curved beak Mostly open sea

predators Elaborate courtship

followed by lifelong pairing

Albatrosses, shearwaters, petrels

Pelicans and Relatives

Pelicans and Relatives

Webbing between toes

Fish eaters

Webbing between toes

Fish eaters

Gulls and RelativesGulls and Relatives

AUKS!!AUKS!!

Common name for the Alcids May fill penguin niche in Northern

Hemisphere Puffins, razorbills, guillemots, dovekies

(little auks) Great auk extinct in 1844

Common name for the Alcids May fill penguin niche in Northern

Hemisphere Puffins, razorbills, guillemots, dovekies

(little auks) Great auk extinct in 1844

ShorebirdsShorebirds

Herons, egrets, plovers, etc.

Found on coastlines usually for feeding

Often common in freshwater

Herons, egrets, plovers, etc.

Found on coastlines usually for feeding

Often common in freshwater

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Marine MammalsMarine Mammals

Endothermic/Homeothermic Hair and mammary glands Viviparous and placental Large, complex brain

Endothermic/Homeothermic Hair and mammary glands Viviparous and placental Large, complex brain

PinnipedsPinnipeds

Relatives of Carnivora Blubber and fur Seals, sea lions and walruses

Relatives of Carnivora Blubber and fur Seals, sea lions and walruses

Seals

Sea Lions and Fur Seals

Walruses

Carnivora - Polar Bears

Carnivora - Polar Bears

Arctic top predators Swim well but hunt on

ice (seals, belugas, etc.) Parental care

Arctic top predators Swim well but hunt on

ice (seals, belugas, etc.) Parental care

Carnivora - Sea OttersCarnivora - Sea Otters

Smallest marine mammal

Lacks blubber but dense fur

Eat a LOT! (Mostly inverts)

Parental care Still threatened

Smallest marine mammal

Lacks blubber but dense fur

Eat a LOT! (Mostly inverts)

Parental care Still threatened

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SireniansSirenians

Manatees and dugongs No rear limbs Paddle shaped tail Thick blubber layer but

almost no hair Four remaining species

(all endangered)

Manatees and dugongs No rear limbs Paddle shaped tail Thick blubber layer but

almost no hair Four remaining species

(all endangered)

CetaceansCetaceans

Largest group of marine mammals Entirely aquatic Convergent evolution

Largest group of marine mammals Entirely aquatic Convergent evolution

RespirationRespiration

Nasal drift Rapid air movement 90% oxygen delivery from lungs! Blood adaptations:

Greater blood volume More erythrocytes with more hemoglobin Extra myoglobin in muscles

Lowered HR and restricted blood flow Lung collapse?? Exhalation before diving??

Why??

Nasal drift Rapid air movement 90% oxygen delivery from lungs! Blood adaptations:

Greater blood volume More erythrocytes with more hemoglobin Extra myoglobin in muscles

Lowered HR and restricted blood flow Lung collapse?? Exhalation before diving??

Why??

EcholocationEcholocation Toothed whales, some pinnipeds and baleen

whales

Toothed whales, some pinnipeds and baleen whales

It’s cold down there!!It’s cold down there!!

Blubber - useful as insulation and as energy reserve

Fur in pinnipeds and carnivora Blood vessels in whale tongues transfer

heat back to core

Blubber - useful as insulation and as energy reserve

Fur in pinnipeds and carnivora Blood vessels in whale tongues transfer

heat back to core

VocalizationWhat purpose does it serve?

Other BehaviorsOther Behaviors

Reproduction - Cetaceans

Reproduction - Cetaceans

Copulation in water Competition and cooperation Sex play 11-12 month gestation Birth Maternal care

Copulation in water Competition and cooperation Sex play 11-12 month gestation Birth Maternal care

Reproduction - PinnipedsReproduction - Pinnipeds

Monogamy vs. polygamy Harems and bachelor groups

Maternal care Variation in nursing period Females return

Delayed implantation allows birth to coincide with return to shore

Monogamy vs. polygamy Harems and bachelor groups

Maternal care Variation in nursing period Females return

Delayed implantation allows birth to coincide with return to shore