THE PRESERVATION OF OUR FAUNA 201 



the set-back, we should probably have discovered that 

 we had in time reached an artificial natural balance, when 

 man would have got some wheat, but neither would the 

 bulb-fly nor its parasites have entirely vanished. We 

 may, in cultivation, force the pace, we do it constantly, 

 but ultimately natural forces assert themselves; a stable 

 condition is reached. 



Game preservation has wrought many changes in 

 nature's balance, and these are often closely connected 

 with the introduction of alien creatures. A new and 

 complex situation arose during the war; its effect is still 

 noticeable. Apart from the previous interference with 

 animal life caused by game preservation methods was the 

 fact that a large number of men were engaged in con- 

 tinuous efforts to decrease the numbers of certain creatures, 

 called by them " vermin," and simultaneously to increase 

 the head of game, a persistent effort to upset natural 

 balance. Many of these men were drafted into the army, 

 artificial rearing was almost entirely neglected, and much 

 of the seasonal shooting or sport was discontinued. 

 Immediately a change was noticeable; predatory animals 

 such as hawks, owls, crows, magpies, jays, stoats, weasels, 

 and foxes increased; rabbits became a nuisance in spite 

 of controlled prices, rats were a perfect plague, and small 

 birds decreased. Unfortunately the issue was confused 

 by a natural catastrophe, the abnormal winter and 

 spring of 1916-17, when so many birds suffered from 

 starvation, and in direct consequence insect life had a 

 chance to increase. If, however, some measure of the 

 decrease in bird life was due to the abundance of predatory 

 creatures, which I believe it was, we can see why the 

 wheat bulb-fly increased, and why the forest trees for 

 several years have suffered defoliation, by the larvae 

 of species of Hibernia and Cheimatobia and other in- 

 sects. Possibly, too, it was a factor in the abnormal 



