CHARACTERS OF FLIGHTLESS BIRDS (PALAEOGNATHAE –OR- RATITAE)

CHARACTERS OF FLIGHTLESS BIRDS (PALAEOGNATHAE –OR- RATITAE)
1. Flightless birds are included in this group.
2. They are usually large birds adapted for running or walking.
 
3. Two to Four toes are present in their legs. For example two toes in African ostrich, 3 toes in American ostrich and Emu and 4 digits in kiwi.
4. Wings are reduced or absent. Feathers bear barbs. Barbules and barbicels are absent.
5. Tail feathers and oil gland absent.
6. Flight muscles are very much reduced.
 
7. Pygostyle, furcula, syrinx are absent.
8. Teeth are absent, caudal vertebrae are free.
9. Sternum is devoid of keel or carina.
10. These birds are discontinuous in distribution.
11. Freshly hatched young ones are covered by feathers.
12- Young ones can lead independent life, (precocious)
13. Penis is found in males.
14. Eggs are hatched by Males.
Ex. Ostrich, Emu, Kiwi, Penguin, Tinamus.
LIST OF FLIGHTLESS BIRDS
AFRICAN OSTRICH (Struthio Camelus)
1. Struthio camelus is true ostrich and is the largest living bird.
2. They are 8 ft. tall and weigh up to 300 lbs.
 
3. Ostriches are found in deserts of Africa and Arabia.

4. Head is small, with a broad beak, neck is long, body is heavy and tail is short.
5. The wings are rudimentary.
6. Hind limbs are long and powerful and have only two digits .
7. These live in flocks; each flock consists of one male bird and many females. This is called polygamy.
8 These are omnivorous birds commonly known as camel birds.
AMERICAN OSTRICH (Rhea americana)
1. These birds are confined to South America.

2. These birds resemble African ostriches in shape and habits.
3. These are smaller than the African ostriches.
4. Three digits are found in each leg.
5. These are the only ratitae birds with syrinx.
KIWI (Apteryx)
1. This is commonly known as Kiwi.
 


2. This is confined only to Newzealand and it is the National bird of New Zealand.
3. Each leg possesses 4 digits.
4. Wings are very much reduced and not covered by feathers.
5. They live in pairs; they are noctural feeding on worms and insects.
6. The olfactory chambers are large and sense of smell is better developed than other birds. Pecten is absent in the eye.
EMU-(Dromaeus)
1. These are regarded as the most primitive birds.
2. Wings are extremely reduced.
3. These are purely monogamous birds, males incubate eggs.
4. Each leg possesses 3 digits. Second largest bird.
5. These are confined to New Guinea and Queensland of Australia.
TINAMUS (Tinamus rhyncodon)
1. This is found in South America and North Mexico.
2. Though it is included in ratitae birds, it possesses several characters of flying birds.
3. Presence of well-developed wings, flight muscles and keel are the characters of
Flying birds -carinatae seen in Tinamus.

4. As they possess characters of flightless birds, they are considered as ratitae birds.
5. Absence of pygostyle, reduced feathers, presence of penis is the characters of ratitae birds.
DIFFERENCES BETWEEN FLYING BIRDS AND FLIGHTLESS BIRDS
FLYING BIRDS (CARINATAE) FLIGHTLESS BIRDS (RATITAE)
1. These are usually small birds with 4 toes in their legs. 1. These are usually large birds adapted for running or walking with 2 or 4 toes in their legs.
2. Feathers have barbules and barbicels. 2. Barbules and barbicels are absent in feathers and barbs are free.
3. Tail feathers are present. An oil gland is present at the base of the tail. 3. Tail feathers are absent. Oil gland is absent.
4. Palate is well developed. 4. Palate is most primitive type.
5. Wings, feathers and flight muscles are developed. 5. Wings, feathers and flight muscles are well reduced.
6. Pygostyle is present. 6. Pygostyle is absent.
7. Furcula is present. 7. Furcula is absent.
8. Syrinx is present. 8. Syrinx is absent.
9. Keel is present in the sternum. 9. Sternum is without keel.
10. These birds are worldwide in distribution. 10. These birds are discontinuous in distribution.
11. Newly hatched young ones lack feathers. 11. Freshly hatched young ones are covered by feathers.
12. Newly hatched young ones cannot lead independent life (Altrices). 12. The young ones can lead independent life (Precocious).
13. Penis is absent in males. 13. Penis is found in males.
14. Eggs are hatched generally by females.Eg: Pigeon, Crow, Peacock, and Sparrow. 14. Eggs are hatched by males. Eg: Ostrich, Emu, Kiwi, Penguin, Tinamus.




















































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