^'°i9?i^'] COLLI X(;E, The StariiH;/. 155 



that the animal matter contains 26.5 per cent, of injurious insects 

 and their larvae, 3.5 per cent, of neutral insects, 2.5 per cent, of 

 beneficial insects, 8.5 per cent, of earthworms, 6.5 per cent, of slugs 

 and snails, 1.5 per cent, of millipedes, and 2 per cent, of miscellaneous 

 animal matter. The percentages of the different items are expressed 

 diagrammatically in Fig. 2. Further inquiry into the nature of the 

 vegetable matter shows it to consist of 20.5 per cent, of cereals, 2.5 

 per cent, of cultivated roots and leaves, 15.5 per cent, of cultivated 

 fruits, 7 per cent, of wild fruits and seeds of weeds, and 3.5 per 

 cent, of miscellaneous vegetable matter of a neutral nature (see 

 Fig. 3). 



If the monthly averages are examined we find that the percentage 

 of animal matter is greatest in April, May and June, the respective 

 percentages being 65, 92 and 87. The highest percentage of fruit is 

 found in July, August and September, and the highest percentage of 

 cereals in September, October and March. In some districts the total 

 percentage of injuries during the months July to October is nearly 

 100, in other words, cereals and cultivated fruits form the main items 

 of food during this period of the year. 



Summarising the above figures, we find that 36.5 per cent, of the 

 starlings' food constitutes a benefit to the agriculturist, 41 per cent, 

 an injuiy, and 22.5 per cent, is of a neutral nature. These percent- 

 ages are expressed diagrammatically in Fig. 4. The difficulty is how 

 to balance these figures. This can be accomplished only by inter- 

 preting the economic value of the different items in the light of experi- 

 ence gained in such work. 



Let us first examine the nature of the benefits. Amongst the 

 insect food we find large numbers of click-beetles and weevils, a few 

 June bugs, wireworms and many beetle larvae. (The starling does 

 not consume anything like the number of wireworms that the rook 

 does.) Surface larvae such as those of the Garden Swift Moth, the 

 Heart and Dart Moth, the Great Yellow Underwing Moth, and the 

 caterpillars of the Winter Moth form a considerable item, also leather- 

 jackets and the larvje of other Dipterous flies. Slugs and snails con- 

 stitute the next most important item. Millipedes ax'e occasionally 

 taken, but are not a large item. 



All the above-mentioned insects are exceedingly injurious to agri- 

 cultural and fruit crops, and the number of individual forms de- 

 stroyed must be very great. It is necessary to bear in mind, how- 

 ever, that the bulk of this kind of food is consumed in April, May and 

 June, that is to say, for a period of about three months the starling is 

 wholly beneficial, for another three months it is partly so, and for 

 the remaining six months it is harmful. 



A point in the starling's favour, is the nature of the food brought 

 to the nest by the parent birds during the nesting season, which 

 covers a period of about three weeks. A volumetric analysis of the 

 stomach contents of 40 nestlings shows that injurious insects con- 

 stitute 89 per cent, of the total bulk of food, neutral insects 1.5 per 

 cent., earth-worms and slugs 6.5 per cent., and miscellaneous matter 

 3 per cent. Amongst the insects we find the larvae of the Great Yel- 

 low Undei-wing Moth, various Noctuid and Geometrid larvae, wire- 

 worms, leather-jackets, and many Dipterous larvje, weevils and 

 numerous small beetles. In addition to feeding the growing and 

 rapacious nestlings upon this diet, there is every i-eason to suppose 

 that during this period the parent birds also partake of a similar 

 one. It is, however, important to bear in mind that this period is 

 confined to three weeks only, or six whei'e there are two bi'oods, 

 and as we have previously shown, while the animal diet of the adults 

 during April, May and June is remarkably high, it is almost negligible 

 during July, August, September, October and March. 



Almost every farmer is aware of the damage done by these birds 

 to autumn and spring sown cereals: large areas of newly sown land 



