Notes: Marine Mammals Sea Otters, Polar Bears, Manatees
• • Sea Otters General Characteristics Order: Carnivora Smallest marine mammal 60 -80 lbs. Raft – group of otters Live in and around kelp beds Right or left handed (keep a favorite rock under their armpit) Lack a layer of blubber Fur – densest fur of any marine mammal • Human 30, 000 hairs per square inch • German shepherd 40, 000 hairs per square inch • Otter – 1, 000 hairs per square inch
Otter’s cont’d • They blow bubbles into their fur • • • for insulation and to help them float. Food – They eat sea urchins, mussels, crabs and other invertebrates. They must eat 7 -9 kg. per day because they have a high metabolism (helps keep them warm). Reproduction • Most breed and give birth in the water • Pups weigh 4 -5 lbs. at birth Pups cannot dive by themselves until they are 2 -3 months old. When sea otters are alarmed or frightened, they hold up their paws and hiss! Almost slaughtered to extinction until protected in 1911.
Polar Bears • Characteristics • Largest predator in the world • Live in the Arctic • Can swim up to 60 miles without stopping to rest – this may take 3 -4 days. • They can do 50 foot dives. • Eat seals which they stalk and capture when they surface to breathe. • They spend the winter in dens
Polar Bears, Cont’d • Reproduction/Offspring • Cubs are born in the winter • • in a den • They weigh 1 pound at birth • Don’t leave the den for 3 months • Stay with mother for 3 years Adaptations • white fur – to help camouflage • black skin – to help trap heat hair is a hollow tube to help funnel sunlight to skin.
Manatees and Dugongs • Characteristics • Order Sirenia – means mermaids • Relative of the elephant – called sea cows • Large lips to feed on sea grass - herbivores • Reproduce slowly – 1 calf every 3 years • Many are damaged by speed boats so speed limit laws have been passed in their habitats. Scars are visible on their backs. Manatee- can reach 15 feet/1, 320 lbs Dugong – can reach 10 feet/930 lbs