1. Class Mammalia All mammals share the following characteristics:
Warm-blooded (endothermic and homeothermic)
Four-chambered heart
Fur or hair (not feathers) to retain heat
Mammary glands to produce milk for young

2. Photographs are property of the Riverhead Foundation
Marine Mammals
In the United States, marine mammals are protected by the Endangered Species Act of 1985 and the Marine Mammal Protection Act of 1972
Prohibits the capture, harming and/or killing of any marine mammal
RF has special permits to handle marine mammals and is the only stranding program in the state of NY
Photographs are property of the Riverhead Foundation

3. Seals, Sea Lions, and Walrus
Members of the order Pinnipedia are nearly exclusively marine
Pinnipeds include:
Seals
Sea lions and fur seals
Walruses

4. Seals, Sea Lions, and Walrus
They are predators, feeding mainly on fish and squid
Streamlined bodies for swimming
Thick layer of fat, or blubber for insulation, food reserves, and buoyancy

5. Sea lions and fur seals vs. Seals
Sea lions and fur seals (Otariidae)
Seals (Phocidae)

6. Photograph is property of the Riverhead Foundation
Seals
Seals (earless pinnipeds; family Phocidae) have 19 representative species
Rear flippers cannot be moved forward
No external ear flap
Claws (and fur) on flippers
Short, robust neck
Photograph is property of the Riverhead Foundation

7. Sea lions and fur seals
Sea lions and fur seals (eared pinnipeds; family Otariidae) have 15 representative species
Rotatable hind flippers
External ear flap
Long, flexible neck
No fur or claws on flippers

8. Walrus
Walrus (family Odobenidae) are large pinnipeds with a distinctive pair of tusks
Both male and female have tusks; can reach 1 meter in length!
Used for defense, and anchoring onto ice
Strictly Arctic!
Benthic-feeder; feeds primarily on clams
“tooth walk” for observing walrus pulling themselves out of water with tusks

9. Sea Otters and Polar Bears
Sea otters and polar bears are marine mammals belonging to order Carnivora
The sea otter is the smallest marine mammal, which lacks a layer of blubber
Instead, the sea otter has extremely dense fur, which traps air against the body for insulation
Hunted extensively for fur nearly to extinction
hairs per square inch!

10. Sea Otters and Polar Bears
Sea otters are found only in the Pacific Ocean, and have the densest fur of all animals
Sea otters inhabit nearshore environments and dive to the sea floor to forage on mollusks, crustaceans and echinoderms (sea stars and urchins)
Must eat ~25-30% of their body weight per day

11. Sea Otters

12. Polar Bear
Polar bears are semi-aquatic mammals that spend a good deal of their life drifting on sea ice in the Arctic
They feed primarily on seals, which they stalk at breathing holes
World’s largest land carnivore
Thick blubber; translucent fur, black skin!
Threatened by the loss of Arctic sea ice!

13. Manatees and Dugong
Sirenians (order Sirenia) include the manatees and dugong
Sirenians, also known as sea cows, have a pair of front flippers, but no rear limbs
Swim with up-and-down strokes of their paddle- (manatee) or V- (dugong) shaped tails
Closest land relative is the elephant!

14. Manatees

15. The Florida Manatee

16. Dugong

17. Manatees and Dugong
Sirenians are the only herbivorous marine mammals; feed on aquatic plants and algae
Some species live in fresh and/or brackish water
Inhabit temperate or subtropical waters
Severely threatened by motor boat collisions, harmful algal blooms, pollution, and severe winters