Birds and Forest Protection 



Dr. C. Gordon Hewitt, Dominion 

 Entomologist, Ottawa, whose work in 

 regard to injurious forest insects is 

 well known to all members of the 

 Canadian Forestry Association, has 

 always endeavored to impress upon 

 all citizens, and particularly upon the 

 young, through the Boy Scouts and 

 other organizations, the value of our 

 birds as destroyers of injurious in- 

 sects and of weed seeds. In a recent 

 address, Dr. Hewitt went into this 

 subject in detail, and from that lec- 

 ture, as it appeared in the Ottawa 

 Naturalist, the following parts relat- 

 ing more particularly to the forest 

 side have been taken: — 



' The motives behind the widespread and 

 increasing movement respecting the pro- 

 tection of our native birds may be includ- 

 ed in two classes, namely, sentimental and 

 practical. Most people, even in this ma- 

 terial age, are sensible of feelings of affec- 

 tion towards our birds, and are delighted 

 when the return of the first spring mi- 

 grants announces the termination of our 

 long birdless winter But the practical 

 considerations underlying the movement 

 are not so generally appreciated, and for 

 that reason aesthetic feelings will be as- 

 sumed and the practical motives discussed. 



'Few people realize the place of insect 

 pests in the general economy of life, but 

 when it is understood that were it not for 

 their controlling factors insects would, in 

 a few years, destroy every form of vegeta- 

 tion, and consequently all animal life on 

 the face of the globe, the significance of 

 such controlling factors will be appreciat- 

 ed. In the United States it is estimated, 

 on a conservative basis, that the annual 

 loss on agricultural and forest products 

 is about eight hundred million dollars 

 ($800,000,000). I have estimated that in 

 Canada, on our field crops alone, the mini- 

 mum annual loss due to injurious insects 

 cannot be less than fifty million dollars; 

 this does not take into account the enorm- 

 ous aggregate cost of controlling insect 

 pests. And yet the most valuable insecti- 

 cidal agencies we have are not only not 

 encouraged, but, in many cases, ruthlessly 

 destroyed. Such a short-sighted and waste- 

 ful policy cannot and must not be con- 

 tinued. 



' The quantity of insect food consumed 

 by birds is almost incomprehensible, but 

 the facts set forth by various investiga- 

 tors on this continent and in Europe give 

 us some idea of the extent to which in- 

 sects go to make up the diets of birds. 

 Insects constitute 65 per cent, of the total 

 yearly food of woodpeckers, 96 per cent, 

 of that of fly-catchers, and 95 per cent, of 

 the 3^early food of wrens. Upwards of 

 5,000 insects have been found in a single 

 bird's stomach. The value of the birds is 

 increased by the fact that at the time 

 when insects are most abundant birds are 

 most active and require most food, espe- 

 cially animal food, to feed their young. 



'A young crow will eat twice its weight 

 in food; a robin weighing three ounces 

 was found by ' Nash to consume five and 

 one-half ounces of cutworms in a day. It 

 is calculated that a pair of tits and the 

 young they rear will consume about 170 

 pounds of insect food during a year. These 

 facts and others to be given later will in- 

 dicate the enormous destruction of insect 

 life that is accomplished by the presence 

 of birds. They constitute one of the for- 

 tunate balances of nature. But man is 

 constantly upsetting the balance. Wood- 

 lands are cut down and give place to open 

 fields; snake fences give way to wire; sub- 

 divisions and town lots obliterate the 

 waste places and often the swamps. All 

 these circumstances tend to drive away 

 the birds formerly resident and breeding 

 in such localities. Then outbreaks of in- 

 jurious insects occur and their depreda- 

 tions are increased and prolonged by rea- 

 son of the absence of such important ene- 

 mies. Therefore, our aim should be to 

 restore the balance by attracting the birds 

 back to our parks and natural reserva- 

 tions. 



'Not only do birds destroy insect pests, 

 but they contribute to the destruction of 

 weeds. Certain species of our native spar- 

 rows are large consumers of such weed 

 seeds as bindweed, lamb 's quarters, rag- 

 weed, amaranth, pigeon grass, etc. 



'The feeding habits of a few of our 

 common species of birds which should be 

 protected may now be considered. The 

 Robin {PlaneMlcus migratorius) probably 

 comes first. Early in the year it feeds ex- 

 tensively on cutworms, those insidious 

 enemies of our garden plants and crops; 

 in March they constitute over a third of 

 the robin's food. It is accused of fruit 

 eating, and yet of all the vegetable mat- 

 er it consumes a large proportion consists 



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