This Power Point Presentation is based upon Aves, which is the scientific name of Birds. Many of the pictures used in this Power Point Presentation is animated. Hope this Presentation proves to be helpful for you.

2. Aves (Birds) are a group of
endothermic vertebrates,
characterised by feathers,
toothless beaked jaws, the
laying of hard-shelled eggs, a
high metabolic rate, a four-
chambered heart, and a
lightweight but strong
skeleton.

3. Birds live worldwide and range in
size from the 5 cm bee
hummingbird to the 2.75 m ostrich.
They rank as the class of tetrapods
with the most living species, at
approximately ten thousand, with
more than half of these being
passerines, sometimes known as
perching birds or, less accurately,
as songbirds.

4. Birds have wings which are more
or less developed depending on
the species; the only known
groups without wings are the
extinct moas and elephant birds.
Wings, which evolved from
forelimbs, give most birds the
ability to fly, although further
speciation has led to some
flightless birds, including ratites,
penguins, and diverse Endemic
Island species of birds.

5. The digestive and respiratory
systems of birds are also
uniquely adapted for flight.
Some bird species of aquatic
environments, particularly the
aforementioned flightless
penguins, and also members
of the duck family, have also
evolved for swimming.

6. Birds, specifically Darwin's
finches, played an
important part in the
inception of Darwin's
theory of evolution by
natural selection.

7. Characteristics of Aves
1. They are worm-blooded
with an exoskeleton of
feathers.
2. Body usually spindle
shaped, with four divisions:
head, neck, trunk, and tail;
neck disproportionately long
for balancing and food
gathering.

8. 3. Limbs paired; forelimbs usually
modified for flying; posterior pair
variously adapted for perching,
walking, and swimming; foot with
four toes.
4. Epidermal covering of feathers
and leg scales.
5. Thin integument of epidermis
and dermis.
6. No sweat glands.

9. 7. Fully ossified skeleton with
air cavities.
8. Each jaw covered with a
keratinized sheath, forming a
beak.
9. No teeth; ribs with
strengthening, uncinated
processes.

10. 10. Single bone in middle
ear.
11. Lightweight bones
(bones that are either
hollow or
spongy/strutted)
12. Endothermic

11. 13. Possess a four-chambered
heart and in general exhibit high
metabolic rates
14. Nervous system well
developed, with 12 pairs of cranial
nerves and brain with large
cerebellum and optic lobes.
Circulatory system consists of four-
chambered heart with two atria
and two ventricles.