Question

why is the midbrain so well developed while the olfactory bulbs are reduced in birds?

Answer 1

Midbrain is the part of central nervous system which control the hearing , vision , motor . They require advanced developed midbrain because the require these opportunities to fly away from the earth . Olfactory lobes are required for smell. Birds do not need smell organs because they get their food by vision. More ever olfactory lobes developed in organisms like dogs for food and defence mechanism but birds can fly for defence. So birds have well developed midbrain than olfactory lobes.