A tree species in Mauritius failed to reproduce because of the extinction of a fruiteating bird. Which one of the following was that bird?

Answer: (b) Dodo

The dodo of Mauritius was said to be needed for tambalacoque (“dodo tree”) seeds to sprout after passing through its gut.

The idea

The dodo was a large flightless pigeon of Mauritius. With no fear of people, it was wiped out within a century of sailors arriving, by hunting and by the rats, pigs and monkeys they brought. The story in the question is that a local tree needed the dodo to eat its fruit before the seed could sprout.

Tree bears hard-coated fruit → Dodo eats it; the seed coat is worn down in its gut → Seed sprouts → Dodo goes extinct → Tree still regenerates; dodo dependence is disputed

Why the others are wrong

(c) Condors are vultures of the Americas.

(d) Skuas are seabirds.

Also know

When the loss of one species causes the loss of another that depended on it, it is called co-extinction. Scientists now doubt parts of the dodo-tree story, but it remains the textbook example.