AGRICULTURAL ORXITHOLOGY. 287 



AGRICULTURAL ORNITHOLOGY 



BY E. MICHEXER, M. D., AVONDALE, PENN'a. 



[The following paper wa» originally iutendcd to embrace a list of all the birds known to have been found 

 in Chester county, Pennsylvania ; but finding that vi-ould be too voluminous for the space allotted, I have 

 omitted the water bii'ds, as they do not specially affect the interests of agriculture by tlieir manner of feed, 

 ing. E. M.] 



I.NSECTrVOROUS BIRDS OF CHESTER COUNTY, PENNSYLVANIA. 



"In tlie construction of tlie universe the Divine Architect, whose creative 

 conceptions and consummate arrangements display the perfection of wisdom, 

 formed it a harmonious whole, amply provided with well-regulated checks and 

 balances. So long as these adjusting powers were not disturbed by extraneous 

 forces, interposed by human agency, an inordinate increase of noxious insects 

 was restrained by the physical oj)eration of the elements, and by the instincts 

 and natural propensities of certain insectiA'orous animals. Among the latter 

 may be enumerated many of the smaller quadrupeds,^ reptiles,^ insectivorous 

 birds,-' and the parasitic and predacious insects.""' 



" The harmony of creation has been interrupted by the wanton destruction of 

 birds and reptiles, and by the intervention of other causes ; and in consequence 

 of this derangement in the economy of nature, the insect vegetable feeders 

 have become more abundant, and consequently more destructive." — D?\ Brinkle. 



It must be plain to all observers that most of our common birds are partly, 

 and many of them almost wholly, insectivorous — that is, insect-eaters. We 

 cannot, for a single hour, watch their movements, their industry and dexterity 

 in capturing insects, without being impressed with the vast numbers which they 

 must every day devour. It is no less certain that the number of birds is being 

 constantly and rapidly diminished from year to year. We need not, therefore, 

 feel sui-prised that, in proportion as the number of birds has been diminished, 

 the insects have increased in a corresponding ratio. Reason should have taught 

 us that it would be so, and experience has verified the fact; and we can hardly 

 err in ascribing the increase of the one to the decrease of the other. Hence it 

 becomes an important inquiry, What are the causes which have so greatly re- 

 duced the number of our birds ? In pursuing this inquiry it will be convenient 

 to divide them into forest birds and field birds. 



The forest birds appear rather to shun the company of man, and to recede as the 

 ai'ts of civilization advance. This may be owing in part to the destruction of 

 the forests, which afibrded them both food and shelter, and in part to the wan- 

 ton destruction of them with their eggs and nests. It is some consolation, how- 

 ever, to reflect that forest birds feed mostly on forest insects, and therefore do 

 not so immediately affect the interests of the agriculturists as those which 

 dwell in the fields. 



The field birds, on the contrary, seem to court domestication, and to seek 

 the protection of man by their familiar approach to his dwelling. They incline 

 to accompany the settlements, and delight to dwell in the field, the orchard, or 

 the garden. Living, as they do, in the very midst of those scenes of insect 

 devastation of which we so often complain, and feeding, as most of them do, 

 on the authors of that devastation, we must be blind, indeed, not to perceive 

 how much we owe to them as a direct check upon the increase of noxious insects. 



1. Rats, mice, shrews, moles. 2. Snakes, frogs, toads, lizards. 



3. Woodpeckers, swallows, crows. 4. Ichneimions, dragon flies. 



