EELATION TO AGRICULTURE 47 



and any further cutting back reacts detrimentally 

 to the plants. Not many winter finches have con- 

 tracted this habit, and those that have more than 

 compensate for their crimes by consumption of 

 weed seeds. 



The Kea Parrot 



In the previous chapter we mentioned the ac- 

 quired habit of the rhinoceros-bird of South 

 Africa of picking at the backs of cattle until blood 

 flows. The birds gained the habit from eating 

 the blood-filled ticks which adhere to the backs 

 of the beasts. In somewhat the same way the 

 kea parrots of New Zealand have evolved a taste 

 for the flesh of sheep. 



Originally these parrots were entirely insec- 

 tivorous, with perhaps a we.akness for succulent 

 fruit. Shortly after the introduction of sheep 

 into New Zealand, they formed a habit of ap- 

 proaching the sheep-stations during the cold win- 

 ter months in order to pick up scraps and offal 

 thrown out by the herders. When a sheep was 

 killed they picked the flesh from the bones of 

 whatever portion was thrown away. So pleasant 

 did the taste of flesh become that gradually the 

 birds forsook their natural diet of fruit and be- 

 gan to attack the living sheep. It is now their 



