DEFINING A SEABIRD • A bird has:

– Feathers– Hollow bones– Wings– Endothermic (warm blooded)– Specialized lungs – air flows in one direction aided by

air sacs

• Live, feed and breed near the sea – depend on sea for food

• Secrete salt from glands in beak or near eyes• Breed in colonies (95% of seabirds) – 10s to 1000s

Only 4% of the world’s 9000 bird species are seabirds

= 372 species

Of the 29 orders of birds

7 contain seabirds

• Spenisciformes (penguins)• Gaviiformes (divers, loons & grebes)• Procellariiformes (albatrosses, petrels

& shearwaters)• Pelecaniformes (pelicans, gannets, boobies,

cormorants, frigatebirds & tropicbirds)• Anseriformes (ducks & geese)• Charadriiformes (gulls, terns and auks)

• 17 species – all found south of the equator• Most are found around Antarctica

(or New Zealand/Australia/Southern America)• But the Galapagos penguin lives near the equator

Adaptations to the marine environment include:• Solid (not hollow) bones – so they can dive• Very hydrodynamic shape – swim up to 15 mph• Wing bones are fused – a solid flipper (instead of a wing)

• Wings “fly” underwater – like sealions• Thick fat layer, plus feathers to insulate• Their feathers are like pins & not branched –

denser packed• Plus behavioral adaptations (e.g. huddling)

Spenisciformes - penguins

Gaviiformes - divers and loons

• Loons are called ‘divers’ in the UK• The northern hemisphere’s answer to penguins

Adaptations to the marine environment include:• Like penguins have solid (not hollow) bones• Simply by exhaling and emptying their air sacs they

can become heavy enough to sink• Feet are near the backs of their bodies

– greater thrust when diving• Have lobed feet (not webbed)

– increased surface area• Can dive to depths of 100s of feet for several minutes• BUT – unlike penguins they can fly (although heavy)

Gaviiformes - grebes

Grebe

• Unlike penguins & loons albatrosses do not spend much time in the water

• Instead they fly over the ocean searching for prey• Usually found in the southern hemisphere• The albatrosses glide in the constant strong winds

around Antarctica

Adaptations to the marine environment include:• Long wingspan (3 - 4 m) but narrow wings –

perfect for long distance gliding• They have a tube on top of their beaks –

allows them to detect changes wind currents• A long hooked beak for catching fish on the wing

Procellariiformes - albatross

• Small sparrow-sized birds• They skim over the surface of the sea looking for

food• Migrate to the equator during the winter• Breed in burrows to avoid predators

Adaptations to the marine environment include:• They have a tube on top of their beaks –

like albatrosses• Also have a hooked beak like albatrosses• Secrete excess salt through their nose tubes • Don’t glide but flap rapidly, very quickly and low

over the tops of waves• Unlike albatrosses, will dive into the water –

sometimes flying through the crest of a wave

Procellariiformes - petrels

• Also skim over the surface of the sea looking for food

• Pelagic – mostly hunting on the open ocean• Have a beak and nose tube like the albatross &

petrel

Procellariiformes - shearwaters

• One of the largest groups of seabirds 67 species

Adaptations to the marine environment include:• All have fully webbed feet = TOTIPALMATE• Most have an elastic pouch of skin hanging below

their beak

Pelecaniformes

• Large birds (with a wingspan of up to 3m)

Adaptations to the marine environment include:• Very thin hydrodynamic shape to dive into the

water • They open their mouths use their throat pouches

to “net” their prey

Pelecaniformes - pelicans

• Primarily tropical

Adaptations to the marine environment include:• Dive from heights of nearly 100’ onto prey• Torpedo shaped - for piercing the water’s surface

Pelecaniformes - boobies

• Found in cool northern regions – nest on rocky cliffs

Adaptations to the marine environment include:• Like boobies, dive onto prey from height• Can hit the water at 60mph• Skull specially adapted to absorb the force of

impact, and to protect their brains from damage

Pelecaniformes - gannets

Pelecaniformes - cormorants

Adaptations to the marine environment include:• Even more streamlined for diving from height• Can dive to depths of 10 m or more• Some species are flightless with large webbed, rear

situated feet• BUT their wings are not waterproof,

so have to keep landing to allow their wings to dry

• Much more agile in the air than the other pelecaniformes

• Opportunistic feeders – mollusks, fish, turtles and even jellyfish

• Will also frequently steal food from other seabirds

Pelecaniformes - frigatebirds

• Feathers are more waterproof than frigatebirds

and so can fly more over open ocean

Pelecaniformes - tropicbirds

• 4 species of duck (EIDER DUCKS) are marine & 4 species of STEAMER ducks (3 are flightless)• They have soft fluffy (well insulating) feathers• The kelp goose is also marine and feeds on algae

Anseriformes –ducks & geese

Account for nearly half of the seabird species 131 speciesIncluding 50 species of gulls44 species of terns22 species of auk8 species of skua (jaeger)

Charadriiformes

Adaptations to the marine environment include:• Hooked beaks, webbed feet and long powerful

wings• Can’t dive like a loon, or fly like an albatross or

swim as well as a cormorant – but are a “jack of all trades”

• Very opportunistic feeders and able to find a niche in almost any open ocean or coastal environment

Charadriiformes - gulls

• Sometimes called “sea swallows” more graceful relative of gulls

• Hunt for food rather than scavenge like gulls• Only have small webbed feet, so not good

swimmers, swoop and catch prey on the wing

Charadriiformes - terns

• Called Jaegers in the US• Look like a cross between a hawk and a gull• Fierce predators with a bad attitude• Most inhabit the southern hemisphere

(although the great skua is found in the north)

Charadriiformes - skuas

• Clumsy in the air but extremely good divers• Usually inhabit colder, northern hemisphere areas

Adaptations to a marine environment:• Narrow, parrot like beaks, that can scoop up

several small fish at a time• Use their wings to fly underwater like penguins• BUT more buoyant than penguins and have to

work harder to stay underwater

Charadriiformes - auks

Although not officially SEABIRDS, other bird species use the marine environment:

• Wading birds in coastal mudflats and estuaries• Herons, Egrets & Spoonbills – freshwater, but also

seen in salt marches and estuaries• Flamingos – live in salt marshes and estuaries (as

well as salt lakes) – filters brine shrimp out of the water

• Kingfishers• Crows – especially the fish crow.

Eat fish and beach carrion• Falconformes: sea eagles and ospreys

OTHER BIRDS FOUND IN THE MARINE ENVIROMENT