Avian flight adaptations

2. Birds have many adaptations for flight.

3. MORPHOLOGICAL
ADAPATAION
1. COMPACT BODY
2. BODY-COVERING OF
FEATHERS
3. FORELIMBS MODIFIED
INTO WINGS
4. SHORT TAIL
5. BEAK
6. MOBILE NECK AND HEAD
7. BIPEDAL LOCOMOTION
8. INTEGUMENT

4. 1.COMPACT BODY
• Strong dorsally and heavier
ventrally ,Helps to maintain
balance in the air
• Wings-high on the thorax
• Lungs, air sacs-low position
• Heavy
muscles,sternum,digestive
organs- central position

5. 2.BODY-COVERING OF FEATHERS
• Feathers are smooth, backwardly
directed, makes the body
streamlined and reduce friction
• Feather covering makes the body
light, protects from environmental
hazards and
prevents loss of heat
• Large quill feathers on the wing
and tail-used for flight
• Tail with a spreading fan of
feathers-effective steering
organ

6. 3.FORELIMBS MODIFIED INTO WINGS
• Forelimbs are modified into unique
and powerful organ-wings
• These organs consist of framework of
bones, muscles etc
• Surface area of wing is increased by
development of elongated flight
feathers-remiges
• Flight feather forms broad surface
• Shape of wing-thick strong edge,
convex upper and concave lower
surface reduces air
pressure

7. 4.SHORT TAIL
• Tails bears a series of long,
strong but light feathers or
rectrices arranged in a fan-like
manner
• Serves as a wheel for steering
during flight
• Helps in counterbalance in
perching

8. 5.BEAK
• Conversion of forelimb to wing is
compensated by presence of bill
or beak
• Mouth is drawn into a horny
beak-used as forceps in
picking-up things
• Also used to build nest, which in
other animals is done by
forelimbs.

9. 6.MOBILE NECK AND
HEAD
• Neck is long and flexible which gives
freedom of movement to head
through a neck.
• It is also used to balance the body
during bipedal.

10. 7.BIPEDAL LOCOMOTION
• Hind limbs occupy anterior position
on the trunk-for arboreal life
• Muscles are well developed and
suited for perching
• When birds sit on the
branch toe close
automatically
• A bird can go to sleep in this
position without the fear of
falling.

11. 8.INTEGUMENT
 Loose skin is modified
for flight
 It is responsible for
extensive movement of
skeletal musculature.

12. ANATOMICAL, PHYSIOLOGICAL
ADAPATAION
1. LARGE MUSCLES OF FLIGHT
2. PERCHING
3. ENDOSKELTON
4. DIGESTIVE SYSTEM
5. AIR SACS & RESPIRATION
6. WARM-BLOODEDNESS
7. EXCRETORY SYSTEM
8. REPRODUCTIVE SYSTEM

13. 1.LARGE MUSCLES OF FLIGHT
• Control the action of wings-muscles of
back is reduced
• (a)Pectoralis major-largest muscle,
arises from sternum & clavicle,
inserted to head of the
humerus.Contraction of this muscle
causes downward stroke of wings-bird
moves up
• (b)Pectoralis minor-thinner than
major,longer,contraction of this muscle
causes upward stroke of the wings.
• (c)Coracobrachialis:small muscle that
arises from sternum and
coracoid,inserted on the humerus,helps
to pull wing downward in flight.

14. 2.PERCHING
• Hind limb re suited for arboreal life.
• Muscles are well developed and
helps in perching.
• Birds settles down on the tree, bend
the legs and exerts a pull on flexor
tendons which make them
automatically to flex and grip the
perch

15. 3.ENDOSKELTON
• Skeletal framework is stout.
• Bones are pnuematic,filled with air
spaces, spongy
• Teeth are lacking, replaced by much
lighter beak
• Vertebrae except at the neck region is
fused
• Rigidity of dorsal part-due to fusion of
vertebrae
• Sternum with well developed
keel serves for the attachment
of flight muscles
• Clavicle fuse to form V shaped furcula-
acts as a spring and keeps the wings
well apart

16. 4. DIGESTIVE SYSTEM
• Rate of metabolism is high, food
requirement is great, rapid digestion
• Selected food has high calorific value,
largely utilized,
minimum indigestible waste
• Digestive system is compact & effective
• Rapid elimination of undigested food-
short rectum –
never stores undigested food

17. 5.AIR SACS & RESPIRATION
• Inelastic lungs-supplemented by
remarkable system of air sacs
• Air sacs –perfect aeration of lungs,
helps in internal perspiration,
thus regulate body temperature
• Avian lungs are completely emptied
with each breath
• While flying movement of wings
contribute to respiration-
compressing &dilating the air sacs,
hence birds breath
more
easily during flight than at other

18. 6.WARM-BLOODEDNESS
• Perfect aeration of blood at high
temperature(40- 46),does not change with
change in environment (homeothermy)
• High & constant body temperature allows birds to
fly at high altitudes
• Also facilitates activeness in every season

19. 8.EXCRETORY SYSTEM
• Uriniferous tubules are provide with henle’s loop-efficient
water absorption
• Coprodaeum of cloaca –efficient in water absorption
• Urinary bladder is absent
• Semi-solid waste is immediately excreted out
• Nitrogenous waste are excreted as uric acid crystals-
important
physiological volant adaptation

20. 10.REPRODUCTIVE SYSTEM
• In female birds, the ovary & oviduct is of one
side(left side) of the body alone .
• This reduces the weight of the body.