*about 9000 species of aves are found
*they are warm blooded animal.
*they have bipeadal feather.
*their fore-limbs are modified into wings.
*the hind limbs are adapted for perching, walking or swimming.
*only preen gland(oil gland) present on tail, and no other gland present on skin.
*Ostrich and parrot lack oil glands
*upper and lower jaws modified into beak,which lack teeth
*legs bear horny epidermal skin.
*respiration occurs in lungs.
*syrinx produces voice in birds not larynx.
*heart is four chambered, sinus venosus is absent.
*renal portal system is very much reduced.
*kidney is metanephric, which directly drain uric acid into cloca through ureter. urinary bladder is absent
*Reha americana (South American Ostrich ) is the only bird which has urinary bladder.
*cerebrum, cerebellum and optic lobes are developed organ of brain.
*birds have 12 pair of cranial nerves.
*bones are pneumatic,means they have air cavity to reduce weight , which helps in flying.
*skull is monocondylic.
*female has well developed single left ovary and oviduct.if right ovary and oviduct are present then they are non-functional.
*sexual dimorphism is found in many birds.
*fertilization is internal
*birds are oviparous, means they lay eggs.
*e.g.-Ostrich, Kiwi. Penguins, Parrot, Duck
*they are warm blooded animal.
*they have bipeadal feather.
*their fore-limbs are modified into wings.
*the hind limbs are adapted for perching, walking or swimming.
*only preen gland(oil gland) present on tail, and no other gland present on skin.
*Ostrich and parrot lack oil glands
*upper and lower jaws modified into beak,which lack teeth
*legs bear horny epidermal skin.
*respiration occurs in lungs.
*syrinx produces voice in birds not larynx.
*heart is four chambered, sinus venosus is absent.
*renal portal system is very much reduced.
*kidney is metanephric, which directly drain uric acid into cloca through ureter. urinary bladder is absent
*Reha americana (South American Ostrich ) is the only bird which has urinary bladder.
*cerebrum, cerebellum and optic lobes are developed organ of brain.
*birds have 12 pair of cranial nerves.
*bones are pneumatic,means they have air cavity to reduce weight , which helps in flying.
*skull is monocondylic.
*female has well developed single left ovary and oviduct.if right ovary and oviduct are present then they are non-functional.
*sexual dimorphism is found in many birds.
*fertilization is internal
*birds are oviparous, means they lay eggs.
*e.g.-Ostrich, Kiwi. Penguins, Parrot, Duck
OSTRICH
KIWI
PENGUINS
