Page:The Kea, a New Zealand problem (1909).pdf/102

98 erythrorhyncha) here formerly fed on ticks and other parasites which infest game and domestic animals; occasionally, if an animal had a sore, the bird would probe the sore to such an extent that sometimes it killed the animal. Since the cattle plague destroyed the immense herds in Ukamihani, and nearly all the sheep and goats were eaten during the late famine, the birds, deprived of their food, have become carnivorous, and now any domestic animal, not constantly watched, is killed by them. Perfectly healthy animals have their ears eaten down to the bone, holes torn in their backs and in the femoral region.”

It will thus be seen that at least three kinds of insectivorous and fruit-eating birds are known to eat fat and meat on special occasions.

When we look at the circumstances that forced the Kea to add to its diet, it would have been more wonderful if the bird had refused to touch the new food.

Unfortunately for science, as the Kea had learned to kill sheep before men were aware of it, we shall never be able now to decide finally what set of circumstances caused him to change; but I think that the truth is confined to the last two of the following three theories.

Whether the change of diet was influenced in the way explained by either one or both of those theories it is hard to say; but so far no other reason can be given to which it is worth while giving serious consideration.

This was the earliest and for many years the most popular; but, when further investigation brought to light many new facts, the theory lost favour, though even to-day some people adhere to it.

The vegetable sheep, after which I have named the theory, is one of the most interesting of our alpine plants. Owing to its cushiony appearance it is often erroneously termed a moss or fungus. The name includes two closely allied plants, which grow especially on the mountainous country of