Seabirds Procellariiformes, Gaviiformes, Sphenisciformes,
Pelecaniformes, and Charadriiformes = 320 spp. Water > 67%
Earths 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 Slide 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 Slide 3 Wilsons Storm Petrel Oceanites
oceanicus Peruvian Diving-petrel Pelecanoides garnotii Greater
Shearwater Puffinus gravis Northern Fulmar Fulmarus glacialis Slide
4 Sulidae Boobies, Gannets All Oceans 3 Genera, 9 Spp Blue-footed
Booby Sula nebouxii Northern Gannet Morus bassanus Order:
PELECANIFORMES Slide 5 Phalacrocoracidae Cormorants All Continents
and Oceans 1 Genera, 38 Spp Slide 6 Order: CHARADRIIFORMES I:
non-seabirds Shorebirds, Gulls, and allies 18 Families 85 Genera
> 300 Spp American oystercatcher Haematopus palliatus Spotted
Dikkop Burhinus capensis Haematopodidae: 1G, 11 Spp, Worldwide
Burhinidae: 1G, 9 Spp, except NA Slide 7 American Avocet
Recurvirostra americana Recurvirostridae: 3G, 10 Spp, All
continents Double-banded Sandgrouse Pterocles binictus Pteroclidae:
2G, 16 Spp, Old World Slide 8 Scolopacidae sandpipers and allies 21
Genera, 88 Spp - Worldwide Wilsons phalarope Phalaropus tricolor
Greater Painted-snipe Rostratula benghalensis Upland Sandpiper -
Bartramia longicauda Slide 9 Black-bellied Plover Pluvialis
squatarola Charadriidae plovers, lapwings 10 Genera, 66 Spp -
Worldwide Blacksmith Plover Vanellus armatus Hudsonian Godwit
Limosa haemastica Slide 10 Hudsonian Godwit Limosa haemastica
Common Snipe Rhynchokinesis Independent opening of the distal upper
jaw Slide 11 Niche Differentiation Bill size and shape determines
habitat and prey Slide 12 Laridae Gulls and terns 13 Genera, 95 Spp
- Worldwide Ross Gull Rhodostethia rosea Black-legged Kittiwake
Rissa tridactyla Little Tern Sterna albifrons CHARADRIIFORMES II:
seabirds Parasitic Jaeger Stercorarius parasiticus Stercorariidae
Jaegers 2G, 8 Spp, Polar regions Slide 13 Alcidae Auks, murres,
puffins 12 Genera, 23 Spp Northern Oceans Tufted Puffin Fratercula
cirrhata Razorbill Alca torda Slide 14 Order: SPHENISCIFORMES
Spheniscidae Penguins Southern Oceans 6 Genera 17 Spp (~50%
threatened or worse) Slide 15 Parallel Evolution wing-propelled
divers in the two hemispheres gullrazorbill Great auk Penguin Slide
16 Niche separation in the Seabirds Slide 17 Distribution of
seabirds is governed by: (1)latitudinal marine zones
(2)distribution of food in the zone (3)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: (1)lower body temp (38
vs 41 degrees) (2)Subdermal fat and stomach oil (3)Flying style
(dynamic and slope soaring) (4)Well-developed olfaction (5)Young
resist chilling and become torpid Slide 18 9 marine water zones
(life zones) Cold water has more nutrients and O 2 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. Marine zones and productivity
Slide 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. Slide 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 doesnt
change the speed of endothermic birds. Slide 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 hrsS. Georgia to S. Brazil (Wadden Sea)(26S
to 67S) Black-legged Kittiwake: up to 60 km and 6 hrsS. Chile to S.
Indian Ocean (Alaska)(17W to 85W) 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
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Slide 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. Slide 23 Breeding and life history Most seabirds are
long-lived (30 or more years) and dont 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 Nio events).
