MARINE BIRDS

Probably evolved from dinosaurs about 160 million years ago.

Their reptilian heritage is clearly visible in their scaly legs and claws and the configuration of their internal organs and skeleton.

HISTORY

EndothermsFeathersHollow BonesHighly Efficient Respiratory System

Lay Eggs On LandIncubate And Care For Young

CHARACTERISTICS

Like marine reptiles, seabirds have special salt-excreting glands in their heads to eliminate the excess salt taken in with their food.

Voracious feedersTrue seabirds avoid land unless breeding

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

Breed in colonies (95% of seabirds) – 10s to 1000s

ADAPTATIONS FOR MARINE LIFE

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

= 372 species

Of the 29 orders of birds7 contain seabirds

SEABIRDS

Spenisciformes (penguins)Gaviiformes (divers, loons & grebes)

Procellariiformes “Tubenoses” (albatrosses, petrels & shearwaters)

Pelecaniformes (pelicans, gannets, boobies, cormorants, frigatebirds & tropicbirds)

Anseriformes (ducks & geese)Charadriiformes (gulls, terns and auks)

GROUPS

17 species – all found south of the equatorMost 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 diveVery hydrodynamic shape – swim up to 15

mphWing bones are fused – a solid flipper

(instead of a wing)Wings “fly” underwater – like sealionsThick fat layer, plus feathers to insulateTheir feathers are like pins & not branched

– denser packedPlus behavioral adaptations (e.g.

huddling)

PENGUINS

Loons are called ‘divers’ in the UKThe 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)

LOONS

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

ALBATROSSES

Small sparrow-sized birdsThey skim over the surface of the sea looking for foodMigrate to the equator during the winterBreed in burrows to avoid predators

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

albatrossesAlso have a hooked beak like albatrossesSecrete excess salt through their nose tubes Don’t glide but flap rapidly, very quickly and low over

the tops of waves

PETRELS

Also skim over the surface of the sea looking for food

Pelagic – mostly hunting on the open oceanHave a beak and nose tube like the albatross &

petrel

SHEARWATERS

One of the largest groups of seabirds 67 species

Adaptations to the marine environment include:

All have fully webbed feet = TOTIPALMATEMost 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 heightCan hit the water at 60mphSkull specially adapted to absorb the force of impact,

and to protect their brains from damage

PELECANIFORMES - GANNETS

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

situated feetBUT their wings are not waterproof,

so have to keep landing to allow their wings to dry

PELECANIFORMES - CORMORANTS

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 - FRIGATE BIRDS

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

DUCKS AND 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 wingsCan’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 gullsOnly have small webbed feet, so not good swimmers,

swoop and catch prey on the wing

CHARADRIIFORMES - TERNS

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 estuariesHerons, Egrets & Spoonbills – freshwater, but also

seen in salt marches and estuariesFlamingos – live in salt marshes and estuaries (as well

as salt lakes) – filters brine shrimp out of the waterKingfishersCrows – especially the fish crow.

Eat fish and beach carrionFalconformes: sea eagles and ospreys

OTHERS