Birds have many adaptations for flight including feathers that are light and reduce drag, hollow bones to decrease weight, strong flight muscles, and other anatomical features like fused vertebrae and sternums that provide rigidity. Their circulatory, respiratory, and digestive systems are also highly specialized to support the high energy demands of flight, with large hearts, lungs with air sacs, and high calorie diets. These extensive morphological and anatomical adaptations allow birds to achieve powered flight and maneuverability in the air.

1. Flight Adaptations In Birds

2. Objectives
1) Morphological
adaptations:
a) Feathers
b) Flight organ
c) Neck
d) Beak
e) Short tail
f) Bipedal
g) Perching
h) Equilibrium
i) integument
2 ) Anatomical
adaptations :
a) Flight muscles
b) Endoskeleton
c) Digestive system
d) Respiratory system
e) Circulatory system
f) Excretory system
g) Brian and sense organ
h) Reproductive organs

3. Introduction
• Masters Of Air – Highly specialized body for flying
• Flightless bird – Ostrich Kiwi, Emu
• Aquatic birds – Pelican, Duck
• Specialization in morphology, anatomy,
physiology :
1. Presence of organ of flight
2. Light and rigid body
3. Supply or production of energy
4. Speed
5. Balancing and control

4. Morphological Adaptations
• 1. Body shape : streamlined , spindle shaped –
minimize resistant by air

5. • 2. compact body :
 Dorsal body – strong, ventral – heavy
Helps in marinating balance in air
Wings at high up on thorax
Low center of gravity

6. High position of lungs
Low position of Heavy
Muscle, Sternum,
Digestive Organ

7. • 3. body covering of feathers:
Smooth , compact, backwardly directed
feathers – Reduce friction
Make body light
Protects from high temperature
Bad conductor of heat – maintain body tem
Envelop air around body –maintain buoyancy
Insulation of body
Wing feather broad surface for striking air

8. • 4. flight organ :
Forelimbs – wings –propelling organ
Special flight muscle
Flight feathers –remiges
During rest folded
Convex , reduce air pressure
Concave
increase air pressure

10. • 5. Beak
Beak – feeding, nest
building ,defense
Acts as forelimb
• 6. mobile neck and head
Long and flexible
Help in reaching to food

11. • 7. short tail
Short and reduced
muscular tail
Light tail feathers or
Rectrices
Serves as rudder
Help in steering,
lifting, counter
balancing during flight

12. • 8. Bipedal Locomotion
Balance entire body weight
Which helps in flight
• 9. Perching
Hind limb specialized for
perching
Specialized muscles in hind
limb for perching
Bird can hold branch

13. • 10. Equilibrium
Wing- high-up on trunk
Lungs- high position
Flight muscle, digestive system –low position
• 11. Integument
Loosely fitted on skin
Help in movement of skeletal muscle

14. Anatomical Adaptation
• 1. Flight Muscle
• Long and striated in
nature –withstand
fatigue
a)Pectoralis Major :
down stroke
b) Pectoralis Minor
or Supracoracoideus
: up stroke

15. c) Coracobranchiali:
depressing of wings
d) Tensor Patagialis:
keep patagia
stretched when
wing is extended

16. • 2. Lightness and rigidity of endoskeleton
Hollow Girdle Principle based skeleton –
strength and lightness

17. Pneumatic bone-
filled with air
Rod like , T- shaped
Compact rigid –
fusion of bones
Teeth absent- beak
Skull bone
reduced, fused

18. All thoracic vertebrae
except last are fused
Rigid dorsal vertebral
column – fusion of
vertebrae
Vertebrae –heterocoelous
– flexibility
Shortening of caudal
vertebrae – phagostyles –
assist in stability

19. • Sternum Bone – T- shaped
girdle – support abdominal
viscera- contained ridges
for attachment of flight
muscle
• Fusion of pelvis with
synsacrum ( all lumber
vertebrae + all sacral
vertebrae + few caudal
vertebrae ) – attachment
for leg, support body
weight

20. • Proximal tarsals +
lower end of tibia –
Tibiotarsus –
strengthen legs
• Fusion of dorsal
tarsals with
metatarsal –
Tarsometatarsus
• Forelimb- 3 digits
fused

21. • 3. Digestive System
High metabolic rate
Selective diet
High caloric value
Gall bladder – absent to reduce body weight

22. • 4. Warm Bloodedness
Body tem -40-46 0C
High tem – help flying high altitude
• 5. Respiratory System
Food oxidized rapidly and liberate high amount
of energy
Oxygen requirement high
Regulate body temperature

23. Lungs with sacs –
reduced specific gravity
of bird
Air sac –enter flight
muscle- reduce friction
During flight – sac
compressed and dilate

24. • 6. Circulatory System
Heart – large size , four chamber
Double circulation- no mixing of oxygenated /
deoxygenated blood
Large amount of hemoglobin

25. • 7. Excretory System
Urecotelic- uric acid, less water
Urinary bladder is absent- weight less
Coprodaeum- water absorbing organ

26. • 8. Brain And Sense Organs:
• Well developed centers - equilibrium, muscle
coordination and instinct
• Cerebellum and cerebrum – highly developed
• Eyes and optic lobe – well developed
• Olfactory bulb- not so developed

27. • 9. Reproductive Organs
Ovary and oviduct – left side of body only
Reduced at right side
Reduction on body weight