Class Aves

• Aves show presence of feathers and beak. Forelimbs are modified into wings.
• Aves have dry skin without glance except oil glands at the base of their tail.
• Aves have hind limbs with scales and are modified for walking, swimming or clasping branches.
• Aves have long, hollow, pneumatic bones.
• The Tympanum of Aves represents their ear.
• Aves have four chambered heart
• Aves are warm blooded [Homoiotherms]
• Digestive track of Aves has additional chambers, crop [for storage] and glizzard [for churning]
• Aves have double respiration. Air sacs are connected to lungs.
• Aves have internal fertilization, are oviparous and their development is direct