Lesson #7 What eats fish: Mammals and birds

1. Lesson #7What eats fish: Mammals and birds Developed by Vernon Asper And Linda Martin USM

2. What are mammals? • All Mammals: • have lungs & breathe air • warm-blooded & maintain a constant body temperature • most bear live young • produce milk & nurse young • have hair at some point during life

3. Marine mammal are those which live in a marine environment Pinnipeds Seals, sea lions, walruses Cetaceans dolphins, whales, porpoises http://nmml.afsc.noaa.goveducationmarinemammals.htm Sirenians Dugongs, manatees Others Sea otters, polar bears

4. Order #1: Cetaceans Whales, dolphins, porpoises • Live entirely in the water • streamlined bodies have thick layers of blubber (fat) • Flippers for front limbs • No hind limbs • Almost no hair • Modern cetaceans divided into two • suborders: • baleen whales and toothed whales

5. Cetaceans: Baleen Whales • Largest animals in the ocean • Spend summers in high latitudes where the krill (their main food) is plentiful, build up blubber for a few months • Migrate to warmer waters to breed, live off blubber during breeding Blue, fin, gray, humpback, sei, and roqual whales www.montereybaywhalewatch.com/

6. Cetaceans:Baleen Whales cont’d • Use baleen to feed • consists of plates of keratin (the same stuff you fingernails are made of) • plates hang in mouth like the bristles of a broom • to feed, they take in a mouthful of water and food, push the water back out through the filter with their tongue www.ifawct.org

7. Cetaceans: Baleen Whales cont’d • Baleen was used for a lot of things that we use plastic for now • It was once used for corset stays • It is still used in some industrial businesses costume.dm.net

8. Cetaceans: Toothed Whales http://nmml.afsc.noaa.gov Dolphins, porpoises, narwhals Beluga, killer, pilot, and sperm whales • Smaller than baleen whales • Have anywhere from 1-65 teeth depending on the species • Slicing teeth • Throats large enough to swallow chunks of giant squid, cuttlefish, etc. • Single blowhole • Use “echolocation”

9. Echolocation • Toothed whales use sonar to “see” in dark or murky water • Just like a ship’s sonar, they bounce sound off of objects and interpret the echoes: Dolphin Pilot Whale Sperm Whale • They can judge distance, speed, size and composition, all from the echo!

10. Dolphins: hooked dorsal fin Beak (snout) Tapered head Gregarious; travel in pods Enjoy bow riding Porpoises: Triangular dorsal fin No beak Blunt head Usually solitary Avoid vessels Cetaceans: Toothed whales Dahl’s Porpoise: www.theporpoisepage.com

11. Bottle Nose Dolphin Interesting Facts: • Most researchers agree that dolphins exhibit a level of intelligence greater then that of dogs and even comparable to that of some primates--but not human beings. • Dolphins can hold their breath for up to several minutes and are capable of rapid and deep dives of more then 1,000 ft. • A female dolphin can potentially bear a calf every two years, but calving intervals generally average three years.

12. Order #2: Pinnipeds Seals, sea lions, walruses • Often come out of the water • Rest • Mate • Give birth • Molt (shed old fur) • Stay crowded together in large groups • Members of certain groups return to the same beach year after year http://nmml.afsc.noaa.gov • Males – bulls • Females – cows • 1 bull + multiple cows = harem • 3 subgroups: earless seals, eared seals, walruses

13. Earless (crawling) seals Elephant, harbor, harp, leopard seals • Largest group • No external ears • In the water • Fast, agile swimmers • Side to side strokes of hind flippers • On land • Drag by front flippers • Wiggle on bellies www.bbc.co.uk/

14. Leopard seals are aptly named! www.birdinfo.com

15. Eared (walking) Seals • Longer, more flexible neck • Longer flippers • Small ear flaps • In the water • Use front flippers to swim • On land • Turn hind flippers forward; walk on all fours Fur seals, sea lions http://nmml.afsc.noaa.gov

16. Walruses • Only living species of its family • Long downward tusks that can reach 3 feet and 12 pounds • Males grow up to 12 feet, 2800 pounds • No external ears • Deeply folded skin over shoulders www.dolphintrainer.com http://collections.ic.gc.ca/arctic/species/walphoto.htm

17. Walruses cont’d • Found in relatively shallow waters of the arctic seas of Eurasia, North America • Live on ice floes in groups of up to 100 • Eat mostly shellfish • Sometimes dive deep in search of food • Follow ice line S in winter and N in summer • Commercially hunted for centuries, now generally banned www.alaskawalrusisland.com

18. Order #3: Sirenians Manatees, dugongs, sea cows • Only marine mammal herbivores • Live in shallow, warm water • Slow swimmers • They have blubber, but not for warmth • Food storage for when food is scarce www.gbrmpa.gov.au

19. Sea Cows • Discovered in 1741 by a member of Vitus Bering’s expedition • Lived around islands in the Bering Sea • No teeth, small head, broad horizontal forked fluke • Dark brown with white streaks or spots * When sea cows were discovered, it was estimated that their population was around 5,000. Because Russian sealers hunted them so much for food and for their fur, just 27 years later, in 1768, they were extinct!! www.sirenian.org

20. Manatees www.floridaconservation.org/ • Tapered body, ending in a rounded flipper • Fore flippers near head • No hind flippers • Adults can be 8-15 ft & up to 1500 pounds • Live singly or in small herds • Protected by law in most areas • Found in SE United States, N South America, and W Africa

21. Dugongs • Found in the Red Sea, East Africa, the Philippines, New Guinea, and North Australia • Rounded body ends in a flipper with paired, pointed, horizontal branches • No hind limbs • Head blends into the body • Broad, square, bristled snout http://sea-dugong.org/

22. #4: Other Marine Mammals There are two other animals that fall under the “marine mammals” classification: * sea otters * polar bears

23. DANGER!!!!! • Most marine mammal dangers are caused by people • Pollution, over fishing, boat collision • Oil spills, plastic trash, poisons • Fishing: • competition for food • get caught in fish nets and drown • Many endangered species • Manatees, monk seals, stellar sea lions, many baleen whales www.floridaconservation.org/

24. Oceanic Birds: Albatross • The Albatross is almost as much a marine animal as a whale • They spend months wandering great distances over the oceans. • They sleep while floating on the ocean surface, drink seawater, and feed on cuttlefish, other small marine animals,

25. Oceanic Birds: Albatross • They return to land only to breed • Well-known species include the wandering albatross, a huge bird with a 3.4 m (11 ft) wingspread.

26. Oceanic Birds: Albatross • Albatrosses nest on barren islands, close to shore; usually the nest is a depression in the ground containing a single egg. • Albatrosses are relatively fearless around humans, who have nicknamed the birds "gooneys."

27. Oceanic Birds: Albatross • Nesting sites near military airstrips on small islands have sometimes created problems because of the birds' interference with takeoffs and landings. • There is a superstition commonly held by sailors that killing an albatross brings bad luck. • The superstition forms the theme of "The Rime of the Ancient Mariner”

28. Oceanic Birds: Penguins • Penguins are true marine animals also; • They only come on shore to breed • The rest of the time they are in the water or on the ice • The Adelie is the "classic" penguin • They resemble that "little guy in a tuxedo."

29. Oceanic Birds: Penguins • Adelie penguins average around 8.5 pounds and are on the shorter end when compared to other penguins since they average around 15 inches. • The male and the female can be distinguished only by behavioral and temporal cues during the mating season.

30. Adelies can Really Swim!

31. Oceanic Birds: Penguins • Adelies, like most penguins, return to the same breeding grounds every year • These “rookeries” are jam packed with penguins at this time • There is nothing to eat there and they make their nests out of rocks because there are no plants

32. Oceanic Birds: Penguins • The diet of the Adelie consists of small fish and various crustaceans • These animals, in turn, feed on zooplankton, which feed on phytoplankton • So, like other marine animals, they are completely dependent on phytoplankton for food.

33. Emperor Penguins • These are the “March of the Penguins” birds

34. http://www.nsf.gov/od/lpa/news/02/images/emperors.jpg Emperor Penguins Clumsy on land, they are incredible under water!

35. http://www.nsf.gov/od/lpa/news/02/images/emperors.jpg Emperor Penguins • Breed at locations far from open water • Have to “march” a long way to get there • Do it in the winter • Not an easy life

36. http://www.emperor-penguin.com/big-chick.html • One egg is produced each year • The male and female take turns tending it. • Young must fend for themselves before the end of summer

37. Antarctic food web • All life in Antarctica relies on plankton • No grass or trees • Growing season lasts for 2 months • Very specialized organisms

38. Bottom dwellers (benthos) rely on food from the surface Depth (meters) Altitude (meters)

39. Summary • Marine mammals and birds are those which spend their lives in the ocean • They have most of the characteristics of their terrestrial relatives but are designed for life in the water • Mammals include otters, seals, manatees, dolphins, and whales, to name a few. • Oceanic birds spend most of their lives in or on the water and derive their sustenance • All life in Antarctica relies on the ocean for sustenance.