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Seabirds

Seabirds. Procellariiformes , Gaviiformes , Sphenisciformes , Pelecaniformes , and Charadriiformes = 320 spp. Water > 67% Earth ’ s surface but seabirds ~ 3% bird spp. Some differences between sea and landbirds: Most feed from the ocean Nasal glands for expelling brine

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Seabirds

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  1. Seabirds Procellariiformes, Gaviiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes = 320 spp. Water > 67% Earth’s surface but seabirds ~ 3% bird spp • Some differences between sea and landbirds: • Most feed from the ocean • Nasal glands for expelling brine • Vary in their dependence of land, but all must return to land to breed • Others hardly ever settle on water (Sooty Tern, frigates) and continuously on • wing away from land • - Active at night

  2. Order: PROCELLARIIFORMES Tube-nosed Seabirds 4 Families Diomedeidae – Albatrosses No. Pacific and So. Oceans 2 Genera, 14 Spp (All threatened or worse) Procellariidae – Shearwaters, petrels, and fulmars All Oceans 14 Genera, 76 Spp Hydrobatidae – Storm petrels All Oceans 7 Genera, 21 Spp Pelacanoididae – Diving petrels So. Oceans 1 Genera, 4 Spp Wandering Albatross – Diomedea exclans

  3. Wilson’s Storm Petrel – Oceanites oceanicus Northern Fulmar – Fulmarus glacialis Greater Shearwater – Puffinus gravis Peruvian Diving-petrel – Pelecanoides garnotii

  4. Sulidae – Boobies, Gannets All Oceans 3 Genera, 9 Spp Blue-footed Booby – Sula nebouxii Northern Gannet – Morus bassanus Order: PELECANIFORMES

  5. Phalacrocoracidae – Cormorants All Continents and Oceans 1 Genera, 38 Spp

  6. Order: CHARADRIIFORMES I: non-seabirds Shorebirds, Gulls, and allies 18 Families 85 Genera > 300 Spp American oystercatcher – Haematopus palliatus Haematopodidae: 1G, 11 Spp, Worldwide Spotted Dikkop – Burhinus capensis Burhinidae: 1G, 9 Spp, except NA

  7. Double-banded Sandgrouse – Pterocles binictus Pteroclidae: 2G, 16 Spp, Old World American Avocet – Recurvirostra americana Recurvirostridae: 3G, 10 Spp, All continents

  8. Scolopacidae – sandpipers and allies 21 Genera, 88 Spp - Worldwide Wilson’s phalarope – Phalaropus tricolor Upland Sandpiper - Bartramia longicauda Greater Painted-snipe – Rostratula benghalensis

  9. Charadriidae – plovers, lapwings 10 Genera, 66 Spp - Worldwide Blacksmith Plover – Vanellus armatus Black-bellied Plover – Pluvialis squatarola Hudsonian Godwit– Limosa haemastica

  10. Rhynchokinesis Independent opening of the distal upper jaw Common Snipe Hudsonian Godwit– Limosa haemastica

  11. Niche Differentiation – Bill size and shape determines habitat and prey

  12. CHARADRIIFORMES II: seabirds Laridae – Gulls and terns 13 Genera, 95 Spp - Worldwide Stercorariidae – Jaegers 2G, 8 Spp, Polar regions Parasitic Jaeger – Stercorarius parasiticus Ross Gull – Rhodostethia rosea Black-legged Kittiwake – Rissa tridactyla Little Tern – Sterna albifrons

  13. Alcidae – Auks, murres, puffins 12 Genera, 23 Spp – Northern Oceans Tufted Puffin – Fratercula cirrhata Razorbill – Alca torda

  14. Order: SPHENISCIFORMES Spheniscidae Penguins – Southern Oceans 6 Genera 17 Spp (~50% threatened or worse)

  15. Parallel Evolution wing-propelled divers in the two hemispheres Great auk Penguin gull razorbill

  16. Niche separation in the Seabirds

  17. Distribution of seabirds is governed by: • latitudinal marine zones • distribution of food in the zone • nesting sites - safe nesting cliffs, islands, promontories • (4) distance of nest to food sources • Another difference between land and seabirds is distance flown to food – 100m to • several km for landbirds to 10s, 100s, or 1000s km for seabirds • Procellariiformes are the most pelagic and the capacity to exploit distant food • supplies is aided by: • lower body temp (38 vs 41 degrees) • Subdermal fat and stomach oil • Flying style (dynamic and slope soaring) • Well-developed olfaction • Young resist chilling and become torpid

  18. Marine zones and productivity 9 marine water zones (life zones) Cold water has more nutrients and O2 and thus support more life Weak winds in the tropics means productivity is 1% that of temperate coastal water. The highest productivity being in polar areas and around continental shelves.

  19. Seabird distribution across marine zones The wide expanse and productivity cold southern oceans is where seabirds reach their max abundance of individuals. Procellariiforms, dominate this region – partially due to short food chains, krill, and loss of krill-feeding whales.

  20. Auks, penguins, diving petrels are the only major seabirds that failed to colonize both hemispheres – and interestingly they also show the most striking evolutionary convergence. All spp hunt by “flying” underwater and this may explain their absence form cold water. A change in water temp of 5 to 15 degrees doubles the swimming speed of exothermic fish, but doesn’t change the speed of endothermic birds.

  21. Foraging zones (2-dimensional) - Inshore (6-8 km from the sea) - Offshore (coast to edge of continental shelf) - Pelagic (over deep ocean) European Shag: 7 km trips of 6 hrs Wandering Albatross (Scotland) Common Tern: 30 km trips of 2 hrs S. Georgia to S. Brazil (Wadden Sea) (26°S to 67°S) Black-legged Kittiwake: up to 60 km and 6 hrs S. Chile to S. Indian Ocean (Alaska) (17°W to 85°W) Northern Gannets: 232 km (540 max) in 13-84 hrs (Scotland) 6091 km/trip; 1534 km from nest gone for 11.6 days ----------------------------------------------------------------------------------------------- Fasting (for young and parent left behind) is associated with these trips Galapagos penguin: < 3 days Magellenic and King: 25-40 days Emperor: walk 150-180 km to open water, forage 500 km, fast for >110 days ----------------------------------------------------------------------------------------------- Foraging zones (3-dimensional) Species differ in whether they obtain food below the surface and the depths and length of time they can remain submerged Here, auks and penguins are the most marine spp. The best human diver can dive 100 m in 4 minutes. King and Emperor Penguins: 304 and 534 m, respectively and 7.5 and 15.8 min, respectively

  22. Most seabirds nest colonially and sometimes in great numbers, In general, nest-sites are of much greater biogeographic importance and limiting factor to population size than is the case for landbirds.

  23. Breeding and life history Most seabirds are long-lived (30 or more years) and don’t breed until several years old. Breeding may take a long time (up to 1 yr in large albatrosses) and occurs only every other year. Many (Procellarids, Alcids) lay a single large egg (up to 25% of adult mass) Both parents incubate or otherwise care for young Most (Alcids are an exception) regurgitate partially digested food or provide stomach oil Pairbonds remain as long as both parents are alive, although divorce can occur, most frequently after unsuccessful breeding. This pattern of life history (reproductive and survivorship schedule) means that most populations are slow-growing and vulnerable to sudden collapses in population size (i.e., recovery is very long). Alternatively, their long life spans allow them to buffer short-term collapses in food supply that shut-down reproduction (e.g., El Nińo events).

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