NATURAL HISTORY. 



A PLEA FOR THE BIRDS. 



BULLETIN OF THE UNIVERSITY OF NEBRASKA. 



The fact that insect depredations are in- 

 creasing in extent each year makes it plain 

 that something must be done to prevent 

 it, and that quickly. We have found that 

 although we are continually making in- 

 creased efforts to destroy these pests, our 

 efforts avail but little and the destruction 

 of our crops goes on. What, then, is to 

 be done? 



The answer is plain. Heed the advice of 

 the naturalist who has made a study of 

 the life histories of the various other liv- 

 ing creatures in the world. Do not con- 

 demn what he says without at least exam- 

 ining into it a little. In his desire for bird 

 protection the naturalist is not prompted 

 by sentiment alone; far from it! Although 

 from the sentimental standpoint solely the 

 friend of birds would have sufficient 

 grounds for making such a request. 



Briefly told, the economic relation of 

 birds to man lies in the services which they 

 render in checking the undue increase of 

 insects, the devouring of small rodents, in 

 destroying the seeds of noxious weeds and 

 acting as scavengers on land and water. 



Those who have studied the subject care- 

 fully have estimated that a loss of nearly 

 $400,000,000 is sustained annually by the 

 cultivators of the soil from insect ravages 

 in the United States and Canada. This 

 does not include the damage done to orna- 

 mental shrubbery, shade and forest trees, 

 nor to the grasses growing on our prai- 

 ries. "Rut if insects are the natural ene- 

 mies of vegetation birds are the natural 

 enemies of insects. ' 



"In the air swallows and swifts are 

 coursing rapidly to and fro, ever in pur- 

 suit of the insects which constitute their 

 sole food. When they retire, the night- 

 hawks and whip-poor-wills take up 

 the chase, catching moths and other noc- 

 turnal insects which would escape day- 

 flying birds. Fly-catchers lie in wait, dart- 

 ing from ambush at passing prey, and with 

 a suggestive click of the bill returning to 

 their post. The warblers, light, active 

 creatures, flutter about the terminal foliage, 

 and with almost the skill of a hummingbird 

 pick insects from the leaf or blossom. 

 The vireos patiently explore the under- 

 sides of leaves and odd nooks and corners 

 to see that no skulker escapes. The wood- 

 peckers, nuthatches and creepers attend to 

 the trunks and limbs, examining carefully 

 each inch of bark for insects' eggs and 

 larvae, or excavating for the ants and 

 borers they hear within. On the ground 



the hunt is continued by the thrushes, 

 sparrows and other birds that feed on the 

 innumerable forms of terrestrial insects. 

 Few places in which insects exist are neg- 

 lected; even some species which pass 

 their earlier stages or entire lives in the 

 water are preyed upon by aquatic birds." 



In nearly every case where the food 

 habits of our birds have been studied we 

 find the good done far exceeds the pos- 

 sible harm that might be inflicted by our 

 birds. Allowing 25 insects a day as an 

 average diet for each bird, and estimating 

 we have about 1J/2 birds to the acre, or in 

 round numbers 75,000,000 in Nebraska, 

 there would be required 1,875,000,000 in- 

 sects for each day's rations. 



Again estimating the number of insects 

 required to fill a bushel at 120,000, it would 

 take 15,625 bushels of insects to feed our 

 birds for a single day, or 937,500 bushels 

 for 60 days, or 2,343,750 bushels for 150 

 days. These estimates are low when we 

 take into consideration the numbers of in- 

 sects that various of our birds have been 

 known to destroy in a single day. For ex- 

 ample, the stomachs of 4 chickadees con- 

 tained 1,028 eggs of cankerworms. Four 

 others contained about 600 eggs and 105 

 mature females of the same insect. The 

 stomach of a single quail contained 101 po- 

 tato bettles; and that of another upward 

 of 500 chinch bugs. A yellow billed 

 cuckoo, shot at 6 a. m., contained 43 tent 

 caterpillars. A robin had eaten 175 larvae 

 of bibio, which feed on the roots of 

 grasses, etc. 



Birds, like all other animals, feed on 

 that food which is most readily obtained, 

 hence the insectivorous kinds destroy 

 those insects which are most numerous — 

 the injurious species. 



Estimating that there is a single grass- 

 hopper, katydid or cricket to each square 

 yard of surface, it would require at least 

 650,000 bushels of these insects to cover 

 the State. Not taking into account any 

 of the myriads of other insect forms nor 

 the rapid rate of reproduction which is go- 

 ing on among them, these alone would be 

 nearly 1-3 enough insect food for our birds 

 during the year. This being true, it is 

 plain that at least twice as many birds 

 could find the proper insect food in our 

 State each year. 



A perusal of the various works that have 

 been written on the economic relations of 

 birds to man will support the statement 

 that if we were deprived of the services of 

 birds the earth would soon become unin- 

 habitable. 



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