Why the kiwi has a very long beak?

The kiwi's beak is long and thin because it is used for searching in the ground and under dead leaves for the caterpillars, worms and insects on which it feeds. The kiwi hunts only at night and remains hidden during the daytime in thick bushes or in holes in the ground. Alone among birds the kiwi has a fine sense of smell. It is perhaps, the last descendant of the large wingless bipeds, which lived on the Earth in very remote times. The only living examples of these birds are to be found in the forest of New Zealand.