Page:The Kea, a New Zealand problem (1909).pdf/117



Winter and early spring are the periods of the year when the Keas are most aggressive in their attacks on sheep, and this fact seems to intimate that the lack of ordinary food does much to instigate the attacks, for a heavy winter generally means a heavy loss of sheep, apart from accidental losses.

This season in the Kea country is usually a very severe one, so much so that some of the other birds make for the plains until the warmer weather returns.

Owing to the high altitude, the cold becomes so intense that the ground is frozen hard for long periods, especially on the shady side of the mountains. These parts for many weeks or even months are as hard as iron, the birds being thus prevented from obtaining the insect larvae which may be concealed under the ground. The Keas must find it very difficult, in severe seasons, to obtain much vegetable food; and this very probably, as we have seen, drives them to satisfy their craving by killing and feeding on sheep.

That very little insect food is obtainable at this season, in some parts, can be seen from the fact that, when at the Mt. Algidus Station in July, 1907, though I spent nearly a whole day in searching in the frozen ground for larvae, etc.,