Page 382 - (DK) Ocean - The Definitive Visual Guide

380 ANIMAL LIFE

Dispersal and Migration NORTHERN GANNET PACIFIC
A typical dispersing species, this bird
Marine birds can range over a huge distance in their lifetime. Some, nests in colonies scattered around the PACIFIC OCEAN
such as the northern gannet, disperse over wide areas of ocean, north Atlantic. When not breeding, it OCEAN ATLANTIC OCEAN
wanders as far south as the tropics,
returning to isolated colonies to breed. The dispersal instinct of usually over continental shelves. INDIAN
northern gannets is strongest in young birds and slowly declines OCEAN
summer distribution
during the four years that it takes them to mature sexually. From SOUTHERN OCEAN
winter distribution
then onward, adults congregate at their colonies in spring and
summer, dispersing again when their chicks have left the nest.
Many other birds, such as the Red Phalarope, migrate between RED PHALAROPE
This migrant nests in the high Arctic, and
distinct summer and winter ranges. During their migrations, overwinters in the southeast Pacific and
they can be seen “on passage” between their two homes. In the eastern Atlantic. An extensive network of
PACIFIC
species profiles on the following pages, distribution maps show migration routes means that it is seen in
OCEAN
all the places where a species occurs—its summer and winter PACIFIC ATLANTIC OCEAN many parts of the world.
ranges, as well as those regions it migrates through. OCEAN summer distribution
INDIAN
winter distribution
OCEAN
SOUTHERN OCEAN

Breeding

Once they reach adulthood, all sea birds have
to come to land to breed. Some species nest
on their own, but many form large colonies—
often because secure nesting sites are few and far TREE NESTER
between. Cliffs and islands are favorite locations, Frigatebirds are unusual among
marine birds in that they nest
as they offer the best protection from predatory
in shrubs and tress.
mammals. Fulmars and auks nest in burrows or
fallen rocks, but most sea birds lay their eggs in the open, using little or
no nesting material. Compared to terrestrial birds, they have small clutches.
Cormorants often lay three or four eggs, but many
MIXED COLONY other marine birds, such as albatrosses and puffins,
Guanay cormorants, boobies, lay a single egg each year. These birds are often
and brown pelicans nest in
dense colonies on the desert long-lived, but their low reproductive rate makes
islands off the coast of them vulnerable to environmental problems, such
Peru—an area rich in fish. as oil spills or climate change.

MARINE BIRD CLASSIFICATION

Of the world’s 27–29 bird orders, only two are exclusively marine:
HERONS AND RELATIVES
the penguins, and the albatrosses and petrels. A further eight orders Order Ciconiiformes
contain a mixture of terrestrial, coastal, and marine species.
119 species
These long-legged birds typically stalk their
prey in shallow water or in marshy habitats.
WATERFOWL LOONS
Order Anseriformes Order Gaviiformes Most live inland, but several are found on
coasts and coral reefs and in mangrove
swamps. They often roost communally at night.
177 species 5 species
Most species of ducks, geese, and swans These sleek, fish-eating birds dive from the
live on, or near, fresh water and often move water’s surface, propelling themselves with
PELICANS AND RELATIVES
to coasts for the winter. A few are totally their feet. Loons are found mainly in the far Order Pelecaniformes KELP GULL
marine, and live in inshore waters. north. They breed inland by fresh water, but
often overwinter at sea. 65 species
This large group of sea birds includes pelicans, WADERS, GULLS, AND AUKS
Order Charadriiformes
cormorants, tropicbirds, frigatebirds, and
ALBATROSSES AND PETRELS gannets. All are fish eaters, catching their
Order Procellariiformes 385 species
food either by plunging into the water from This diverse order contains coastal and
the air or by diving from the surface. Found oceanic species, including many long-
142 species
Totally marine birds occurring throughout all worldwide, they live on coasts and at sea and distance migrants. Diets are varied and
oceans, albatrosses and petrels return to land often feed in flocks. Some species, particularly feeding methods range from plunge-diving
only to breed. Their external nostrils lend a cormorants, also frequent freshwater habitats. to shoreline scavenging. Many species are
good sense of smell. Most remain airborne for gregarious, feeding and nesting in colonies.
KING PENGUIN
days, snatching food from the sea’s surface.
BIRDS OF PREY
Order Falconiformes KINGFISHERS AND RELATIVES
OCEAN LIFE 18 species 23 species Predatory birds, these species have hooked 230 species
PENGUINS
Order Coraciiformes
Order Sphenisciformes
GREBES
Order Podicipediformes
333 species
These exclusively marine birds have lost
These are primarily birds of forests or fresh
bills and sharp talons for snatching their prey.
water, although some species feed along
These fish-eating birds have lobed feet set
As a group, birds of prey are largely terrestrial,
the ability to fly. Most species are found in
the Southern Ocean, but their range also
coasts and inshore waters. They dive on
far back along their bodies. Most grebes live
but some species specialize in catching fish,
and can often be seen on coasts. They rarely
in freshwater habitats, but some migrate to
prey from the air, taking off again directly
extends northward in cold-current regions,
coastal waters after the breeding season.
venture far out to sea.
reaching as far as the Galápagos Islands.
after catching it, although they can swim.