gS 



Oligochaeta or Earthworms, Pulmonate Molluscs or Slugs 

 and Snails, land Isopods or Wood-lice, certain Acari or 

 Mites, and the great class of the Insects. 



Dealing first with INJURIOUS ANIMALS. BIRDS (i), 

 ( 2 )> *\3) merit some amount of attention, but the fact can- 

 not be emphasised too strongly that we possess extra- 

 ordinarily little reliable knowledge concerning the food 

 of some of our very commonest birds. Both the British 

 Association and the Board of Agriculture recognise that,, 

 before any effective legislation can be recommended, a 

 very full scientific enquiry is needed. It is necessary, 

 for instance, to examine and tabulate the contents of the 

 crops of ^certain common birds in each month of the 

 year so that an opinion may be formed of the benefits or 

 injuries caused by them at the different seasons. It is 

 further necessary that some estimate should be made of 

 the available food in the district where the birds were 

 feeding when killed, in order to decide whether the foods 

 discovered in the crops were selected from choice or 

 necessity. Much information is also desirable as to the 

 food of nestling birds. Fortunately some progress is 

 being made towards supplying this much needed informa- 

 tion, and the Department of Economic Zoology in this 

 University is performing a useful part in the work on 

 behalf of the Board of Agriculture. Certain species of 

 wild birds may be direct-injurious by feeding upon or 

 injuring plants or parts of plants; others are indirectly 

 harmful in that they may feed upon forms of animal life 

 which are in themselves beneficial. Fortunately there 

 are very few species of birds which we may declare to 

 be wholly destructive and, of these, the House Sparrow 

 and Wood Pigeon are the most important. The Black- 

 bird also appears to have very little utility in the eyes 

 of man, and is a most persistent devourer of fruit. On 

 the other hand, there is a large number of birds whose 

 role is doubtful ; in many cases we lack adequate knowl- 

 edge to judge fairly as to their feeding habits, but they 

 ;>11 appear to have a good deal of utility in their favour. 

 Among these may be cited the Song Thrush, Great and 

 Blue Tit, Greenfinch, Chaffinch, Rook, Robin, Linnet, 

 Yellow-hammer, Skylark, Starling, Woodpeckers and 



* The numbers in brackets refer to the literature which is 

 listed at the end of this series of lectures. 



