Brown pelican Fig 11 24 I Seabirds C
Brown pelican Fig. 11 -24 I. Seabirds C. Red-footed booby Pelicans and Relatives (Pelecaniformes) • • 1. Webs between all four toes Mostly coastal, tropical and warm temperate Pelicans • • 2. Boobies • • • Frigatebird Subsurface feeding with gular pouch Dive to capture prey below surface video • Use subcutaneous air sacs to return to surface 3. Unusual courtship behavior video Resource partitioning: foraging ranges (blue-footed – nearshore, masked – intermediate, red-footed offshore) Dive (up to 30 m!) to capture prey below surface video Cormorants • • 4. Swim on surface; dive (to 40+ m!) to catch prey video Lack oil glands; must dry after swimming Frigatebirds • • Impressive courtship displays video Skim surface for prey; may steal fish Cormorant
I. Seabirds D. Tubenoses (Procelariiformes) Albatross Fig. 11 -28 • Tube-shaped nostrils; incl shearwaters 1. Albatrosses • • Wingspans up to 11 feet; gliders video Most common in Southern Ocean; some in N Pacific 2. Petrels • • Includes smallest Antarctic endotherm Some dive; others patter to catch prey video Wilson’s storm petrel Manx shearwater
I. Seabirds E. Penguins (Sphenisciformes) • • • Flightless; most obligately marine birds Four of 17 species in Antarctic Heat retention critical • • • Densely-packed feathers (trap air) Subcutaneous fat layer (buoyancy) Awkward on land (walk, toboggan) • • • More agile in water (up to 20 mph) “Fly” with wings; steer with legs/feet May “porpoise” while swimming video Diet: fishes, squids, krill Male guards single egg video • • Emperor penguin May feed chick from crop Most predators aquatic Emperor Fig. 11 -32
II. Mammals • • Endotherms, homeotherms Hair to conserve body heat • • • Still expend ~10 x as much energy as fishes of comparable size Brain – Large, complex Reproduction • • Milk produced by mammary glands Monotremes (platypus, echidnas) • • • Lay eggs No nipples (young lick milk from fur on mother’s belly) Marsupials • • • Viviparous Simple placenta that provides nutrients and oxygen from mother Young emerge from mother very early in development Finish development in marsupium (pouch), nursing from nipple Eutherians (”placental” mammals) • • • Viviparous Complex placenta Extended parental care • • Increased resource input from parent(s) Increased survivorship for offspring
III. Marine Mammals A. Carnivora (Order) 1. Sea otter (1 species) • • • Smallest marine mammal (average male 25 -35 kg) No blubber layer • Insulation from air trapped in dense fur (~3. 5 x as dense as human hair; guard hairs + underfur) • Feet can lose heat; out of water at surface Mainly occur near shore Keystone predators in west coast kelp forests • Voracious – Eat up to 25% of body weight daily (sea urchins, mollusks, crustaceans, fishes) • Bring food to surface; feed while lying on back in water video Females typically bear one pup on nearshore rocks
III. Marine Mammals A. Carnivora 2. Fig. 12 -3 Polar bear (1 species) • • • Semiaquatic: Considerable time in water • Large body (reduces heat loss) • Dense fur (guard hairs, underfur) • Thick subcutaneous fat layer • Black skin Feed primarily on seals • Capture prey through breathing holes in ice video • Can consume up to 10% of body weight in 30 min. Impacted by climate change • Loss of sea ice – Affects feeding • Shorter winters – Affects hibernation
III. Marine Mammals B. Pinnipedia (suborder) • Three families • • Evolved from terrestrial carnivores Predators – Fishes, squids Most prevalent at high latitudes Streamlined bodies • • Adapted for swimming & diving Blubber layer under skin • • Insulation Buoyancy Energy storage Inhibit loss of body heat through • • • Eared seals (Otariidae) True seals (Phocidae) Walruses (Odobenidae) Large body size (low surface: volume) Bristly hair Adaptations for diving 1. California S
Eared seal (Otariidae) Long neck • Pectoral swimming video • Walk on land video True seal (Phocidae) Short neck • Caudal swimming video • Undulate on land video Fig. 12 -4
III. Marine Mammals B. Pinnipedia (suborder) • Three families • • Evolved from terrestrial carnivores Predators – Fishes, squids Most prevalent at high latitudes Streamlined bodies • • Adapted for swimming & diving Blubber layer under skin • • Insulation Buoyancy Energy storage Inhibit loss of body heat through • • • Eared seals (Otariidae) True seals (Phocidae) Walruses (Odobenidae) Large body size (low surface: volume) Bristly hair Adaptations for diving 1. California S
1. Diving Adaptations 2. Mammalian Diving Reflex 3. Bradycardia 4. Peripheral 5. vasoconstriction 6. Oxygen reservoir in 7. tissues 8. Collapsible ribcage
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