4o8 



NATURE 



[July 25, 19 1.8 



of our insectivorous birds in controlling- insect 

 life. 



W^hilst no one possessing a knowledge of the 

 food habits of wild birds will for a moment contend 

 that any species will ever exterminate any species 

 of injurious insect, it is equally clear that if present 

 in sufficient numbers our insectivorous birds do 

 materially help to maintain the balance of Nature, 

 and so prevent certain species of insects from be- 

 coming; so numerous as to assume the dimensions 

 of a plague. There is now ample evidence to prove 

 this, both in our own country and elsewhere. 



Unfortunately, in this country, the species of 

 wild birds that are truly insectivorous in their 

 habits are not plentiful. During the past few years 

 two causes have materially tended to bring about 

 a great reduction in their numbers, viz. the 

 severity of the winters of 1916-17 and 1917—18, 

 particularly the former, and the misguided 

 enthusiasm of certain individuals who, in and 

 out of season, claim protection jfor practically 

 every species of wild bird. This latter cause, in 

 our opinion, has been as fully disastrous as 

 the severity of our climate. When a certain 

 section of the educated public shuts its eyes to 

 the enormous depredations that a comparatively 

 few injurious species of wild birds commit, and 

 is so prejudiced as tq misrepri^sent facts, one 

 result is inevitable, viz. those who are the sufferers 

 and losers wrongly take matters into their own 

 hands and proclaim a ruthless war on all species 

 of wild birds. This is what has taken * and is 

 taking place in the country at the present time, 

 much to the detriment of the agriculturist, fruit- 

 grower, etc. Moreover, this is likely to continue 

 so long as the biased view of uniform protection 

 is advocated, with the result that year by year 

 we shall see great plagues of caterpillars making 

 their appearance and devastating the countryside. 

 Crops will be lost, the supply of our home-grown 

 food materially lessened, and the numbers of 

 our insect-eating wild birds must continue to 

 grow less. 



The outlook is not a cheerful one, and it is 

 fraught with exceedingly grave possibilities, much 

 graver and more far-reaching than most people 

 realise. 



With the first cause we are, at present, unable 

 to deal, although it is exercising the minds of many 

 as to the best manner in which to counteract or 

 checkmate this misguided and pernicious zeal. For 

 the second, however, we believe there is a remedy, 

 if not wholly, at least in part, viz. the enlighten- 

 ment of the agricultural community as to the part 

 these birds play in the economy of Nature ; and this 

 is the immediate object we have in view. For we 

 believe that if, without bias or prejudice, the facts 

 are truthfully and carefully laid before those in- 

 terested, this terrible destruction will be arrested 

 to an appreciable extent. 



The thoughtful reader will no doubt inquire, " Do 

 not the Wild Birds' Protection Acts afford complete 

 protection to these species of birds and an effective 

 means of preservation ? ' ' Our answer is " No. " To 

 a very large extent the Act of 1880 and its four 

 NO. 2543, VOL. lOl] 



j supplementary Acts are practically dead letters. 

 From 1880 to the present time they have all 

 proved largely ineffective. 



The actual number of species of insectivorous 

 wild birds we have in this country is compara- 

 tively small, and many visit us for only a brief 



I season of the year. Of the few that remain 

 throughout the year a heavy toll has been taken. 

 Let us consider briefly the nature of the food and 

 the feeding habits of some of these. 



The fieldfare, water ouzel, wheatear, whinchat, 

 stonechat, redstart, and robin are all above sus- 

 picion. The warblers and wrens (excepting the 

 whitethroat and blackcap) belong to a like cate- 

 gory, as also the hedge accentor, dipper, tits, 

 wagtails, pipits, flycatchers, swallow, martins, 

 and tree creeper. Of the finches we must except 

 the greenfinch, chaffinch, house sparrow, and bull- 



I finch, the two latter being wholly injurious. So 

 far as their food habits are known, none of the 

 buntings are injurious. In some districts the 

 cprn bunting is rather plentiful and has been 

 accused of damaging grain and ricks, but much 

 more careful investigation is necessary before con- 



I demning it. All the larks do far more good than 



j harm, whilst the swift, nightjar, woodpeckers, wry- 



I neck, kingfisher, cuckoo, and owls are all most 

 beneficial. Thus, of the 280 species of British 

 birds, excepting those aquatic or littoral in their 

 habits and the game birds, we have somewhat 



j fewer than a hundred insectivorous species, many 

 of which are quite rare. Surely it is to the inter- 

 est of the agriculturist and fruit-grower to do all 

 in their power to help td protect and increase 

 these beneficial species, which constitute a really 

 important factor in crop production. 



Some during the whole of the year, and others 

 during the period they are in this country, are 

 feeding almost entirely upon insects and the seeds 

 of weeds. It is difficult to estimate the enormous 

 bulk of food that they consume, but we can form 

 some idea when it is stated that a bird about the 

 size of a skylark consumes about 6 lb. of food per 

 year, so that io,o«o birds would require about 

 27 tons of food in a year, of which fully half or 

 more consists of insects and caterpillars. 



Taking a miscellaneous lot of insects and cater- 

 pillars from the stomachs of ten skylarks, we find 

 that in the different individuals, according to the 

 particular species of insects eaten, 174, 160, 

 162, 162, 177, 182, 156, 138, 154, and 156 weigh 

 exactly one ounce, or an average of 162, so that 

 10,000 birds would consume 78,382,080 insects in 

 a year, whilst every 1000 birds would account 

 for nearly 8,000,000, and each bird ah average of 

 8000 per year. In all probability our smaller 

 species of insect-eating birds consume a number 

 of insects far in excess of these figures. 



Bird counts, such as have been carried out in 

 the United States of America, do not exist in this , 

 country, so we cannot state even approximately 

 the number of insect-eating birds we have in the 

 United Kingdom, but assuming that there are 

 32,000,000 acres of land under cultivation and 

 that we have a pair of birds to every four acres. 



