Why is the flesh of the Indian hornbill peculiarly aromatic?

Because it feeds on wild nutmegs, which grow abundantly in its native place, the Molucca Islands.

Why is another species of the above-mentioned bird called the jealous hornbill?

Because he feeds the female during her incubation; and, during his absence in search of food, should he find on his return, the marks of another bird near the nest, he will, it is said, inclose the female in the nest, and leave her to perish. - Horsfleld.