6 SIEUR DE MONTS NATIONAL MONUMENT 



as the range and migration of species, their most favorable 

 habitat and environment, their breeding and feeding habits, 

 the merging of varieties, or the possible development of 

 varieties into distinct species under changing conditions. 



Nature moreover, is not an unrelated patchwork but a 

 complex in which no constituent part can be destroyed with- 

 out affecting to some degree the whole, and disturbing the 

 well-regulated balance. Nor, with our limited knowledge, 

 are we ever aware how essential any particular species of 

 animal or plant may be in nature's economy, nor how impor- 

 tant to ourselves, until, perhaps, realization of its useful- 

 ness comes all too late. 



A striking instance in point occurred within the last 

 few years. 



A large sheep owner on one of the grassy islands off the 

 Massachusetts coast had reason to believe that the crows, 

 which flocked to his meadows in great numbers, were in the 

 habit of feeding occasionally upon his young lambs. He 

 accordingly prosecuted a relentless warfare on these feathered 

 enemies of his flock. 



The next year his fields were yellow and barren; the 

 grass had all been killed by the larvae of the Junebug. In- 

 structed by a friendly ornithologist, he discovered, to his 

 chagrin, that the crows had been feeding almost exclusively 

 upon these destructive grubs and that as the result of his 

 campaign he had lost many more lambs from starvation 

 than the light toll he had accused the crows of taking. 



This is but one example of the immense value of certain 

 birds — and, in this case, of birds popularly considered among 

 the most harmful and useless — as our defenders against 

 fatally destructive foes. 



The exact role played by the different species, however, 

 can be fully discovered only after many more years of ac- 

 curate research. If, in the meantime, useful species are 

 largely diminished, or perhaps totally destroyed, through lack 

 of proper protection, the special benefits they bring are lost 

 forever. 



