There are approximately 10,000 living bird species globally. Modern birds are characterized by feathers, a beak without teeth, laying hard-shelled eggs, a high metabolism, a four-chambered heart, and a lightweight but strong skeleton. While most birds can fly, some are flightless like ratites and penguins. Birds have specialized respiratory and digestive systems adapted for flight and many species undertake long or short migrations. They communicate visually and vocally and live socially, with extended parental care of eggs and offspring.

1. Flying Animals
 They are around 10,000 living species of birds around the
glob.
 Modern birds are characterized by:
 Feathers
 a beak without teeth .
 the laying of hard-shelled eggs.
 a high metabolic rate.
 a four-chambered heart.
 a lightweight but strong skeleton.

2. Flying Animals continue
 All living species of birds have wings—the now extinct
flightless Moa of New Zealand was the only exception.
 most bird species can fly, with some exceptions, including
ratites, penguins, and a number of diverse endemic island
species.
 Birds also have unique digestive and respiratory systems
that are highly adapted for flight.
 Many species take on long distance annual migrations,
and many more perform shorter irregular movements.

3. Flying Animals continue
 Birds are social; they
communicate using
visual signals and
through calls and songs,
and participate in social
behaviors, including
cooperative breeding
and hunting, flocking,
and mobbing of
predators.

4. Flying Animals continue
 Eggs are usually laid in a
nest and incubated by
the parents.
 Most birds have an
extended period of
parental care after
hatching.
 The picture on the right
is a robins nest.

5. hummingbirds
 hummingbird are the
smallest birds on
earth (length of 5
centimeters).
 Hummingbirds are small
birds capable of hovering
in mid-air due to the
rapid flapping of their
wings.

6. Hummingbirds continue
 They are the only birds
that can fly backwards.
 There are 337 species
world wide, 23 North
American species, and 5
Michigan species.

7. Hummingbirds continue
 .A female hummingbirds
are bluish green with a
pale gray underside. The
tips of their tail feathers
have white spots.
Breeding males have a
reddish to pink head,
chin, and throat. The
female lays only two eggs
at a time.

8. Ostrich
 Ostrich is the largest
bird on earth(9ft).
 The Ostrich is one or
two species of large
flightless birds native to
Africa, the only living
member(s) of the genus
Struthio.

9. Ostrich continue
 Some analyses indicate
that the Somali Ostrich
may be better considered a
full species apart from the
Common Ostrich, but
most taxonomists consider
it to be a subspecies.
 The Ostrich is the largest
living species of bird and
lays the largest egg of
any living bird.

10. North American Robin
 The American Robin or North American Robin (Turdus
migratorius) is a migratory songbird of the thrush family.
 It is named after the European Robin because of its
reddish-orange breast, though the two species are not
closely related, with the European robin belonging to the
flycatcher family.
 The American Robin is widely distributed throughout
North America, wintering south of Canada from Florida to
central Mexico and along the Pacific Coast.

11. North American Robin continue
 A Robin lays three to five
light blue eggs per mate.
 The eggs hatch after
14 days, and the chicks
leave the nest a further
two weeks later.
 The chicks are fed:
 worms
 Insects
 berries

12. Bird Eggs
 Bird eggs are laid by
females and incubated for
a time that varies
according to the species; a
single young hatches from
each egg.
 Some birds lay eggs even
when not fertilized (e.g.
hens); it is not uncommon
for pet owners to find their
lone bird nesting on a
clutch of unfertilized eggs,
which are sometimes
called wind-eggs.