Question

Which of the following is not a flight adaptation?
(a)Uncinate processes of the thoracic ribs
(b)Formation of the pygostyle
(c)Fusion of pelvis with synsacrum
(d)Short, stout, peg-like beak

Answer 1

Hint: Birds have various physical adaptations that enable a streamlined flight. These include lightweight body parts and skeletons. Other modifications in birds are not for flight, but for scratching barks of trees, for picking food from surfaces, and so on.

Complete step by step answer:
Birds are endowed with various physical modifications apart from their wings that help in flying, the flight adaptations.
- The adaptations can be categorized as anatomical and morphological.
- The anatomical modifications are as follows: streamlined body and feathers, reduced and pneumatic bones, absence of teeth, and forelimbs modified as wings.
- The beak is an external anatomical structure that is used by the bird for killing prey, fighting, preening, probing for food, courtship, and feeding young. It is not used for flight.

So, the correct answer is ‘short, stout, peg-like beak’.

Additional information: The morphological modifications include feathers that cover the body to reduce air friction, bipedal locomotion, a short tail, etc.
- Uncinate processes are articulations in the thoracic region that help in flight. They overlap the successive ribs to reinforce the rib cage.
- The pygostyle is a modification of the pelvic area that is an attachment site of tail feathers. The last few caudal vertebrae are partially fused to form the pygostyle.
- The pelvic bones are fused with the lumbar and sacral vertebrae. The fused portion is known as the synsacrum. This structure increases strength and reduces weight.

Note:
Feathers of the bird also help in maintaining temperature.
-The pelvic bones are also known as the innominate bones.
-Birds even have well-developed brains and keen eyesight. During flying, birds must have very
quick reactions. When landing on a tree or cliff, a bird has only a few seconds to identify an area to land safely and avoid crashing. Most birds have keener eyesight than humans.