THE PRESERVATION OF OUR FAUNA 207 



results? the destruction of the native fauna or the 

 colonists' stock, but not of the prolific alien. 



Later enthusiasts have brought us the little owl and 

 grey squirrel, and we have yet to see the full results of the 

 folly of introducing successful colonists. At Woburn 

 already it has been necessary to have a squirrel drive, 

 and though neither squirrel nor little owl may be guilty 

 of all the crimes laid to their charge, it is certain that as 

 both are rapidly spreading some other creatures are 

 suffering. I have heard complaints from Hertfordshire 

 and North ants, where the little owl flourishes, that the 

 tawny and barn owls are decreasing; there is only a certain 

 catchable quantity of owl food, and the smart little owl 

 is getting the pick. The bird has now reached our area, 

 where during the last ten years or so the barn and tawny 

 owls have increased ; what will the next decade show ? 



There are many introductions for which we are not inten- 

 tionally responsible, creatures which travel with and in our 

 food supplies. Many of these come merely as stowaways 

 and perish in an inhospitable land, but others, the hangers- 

 on of civilisation, follow man wherever he takes or sends 

 his supplies. The codlin moth, estimated to cost America 

 at least 2,000,000 annually, we sent from Europe, and in 

 return we have to thank America for the American blight. 

 Cockroaches travel from various parts of the world, for 

 they are great navigators, and colonise wherever they 

 land. The Mediterranean flour moth is everywhere, 

 its land of origin is uncertain, and that small weevil, 

 Calandra granaria, is a similar cosmopolitan pest. These 

 and many others, too numerous to mention, increase and 

 spread as trade increases and spreads. We must investi- 

 gate their life story and take whatever course we can to 

 reduce them to their original status. 



Having realised that man not only has been, but still is, 

 responsible for great changes in animal life, many of which 



28 



