The Kea: a New Zealand problem/Chapter 10
CHAPTER X.
TIME OF ATTACK.
Oh! the dew of darkling mornings on the grasses green and grey!
Oh! the flush before the saffron, and the blushes of the snow!
Dark ratas stalking down the gorge (a-waiting for the day)
To the sheen of rippling waters in the shingle sweep below.
—M. C. Keane.
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., that I thought the Kea might fancy, hunting in all likely situations, both in the forest and the mountain side, I found only a very meagre supply.
Not only is food scarce in winter, but the sheep are easier to kill, for the heavy snow-storms which cover the country bury or half-bury a large number of sheep, and as they are in many cases unable to move they become an easy
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Kea country: Arthur Valley, looking down from McKinnon Pass.
prey to the hungry birds. In early spring the climatic conditions are if anything intensified, and ordinary food is still scarce.
To add to this, the Kea often nests at this time, and the work of feeding his family makes him very bold and daring. During the late spring and early summer the ordinary food is more plentiful; the birds kill fewer sheep, and they do not become a menace again until the middle of the summer.
This summer trouble may be accounted for by the fact that at this season most of the snow on the lower slopes has been melted; and the sheep, keeping to their usual habit of making for the sky line, soon find themselves among the Keas. The birds’ opportunity is intensified by the fact that every night the sheep return when possible to particular places on the mountain side to sleep. These are termed “camps,” and here the murderers are sure of finding a large supply of animals on which to experiment.
Their attacks, however, are not altogether confined to any special time, for they have been known to attack sheep at all seasons of the year. Still, from what I can gather, autumn seems to be the time of fewest attacks. No doubt the plentiful food supply, and perhaps the fact that the sheep have been shorn, thus giving the birds a poor hold on the animals’ backs, account for this.
All my correspondents agree that the favourite times of the day for the bird to commit its depredations are the early morning and the evening; for, like its cousin, the Kaka, whether killing sheep or not, it is always lively at these times.
For this reason it is difficult to obtain photographs of the birds actually attacking sheep, for the lack of light and the absence of the shepherd at these times makes the chance of obtaining a snap-shot extremely small. They have been known to attack at all hours of the day; but they seem to confine most of the work to the early or late hours.
When attacking in the middle of the day it is nearly always in dull or foggy weather, though rare cases are known of their killing sheep even in bright sunshine.