. Useful birds and their protection. Containing brief descriptions of the more common and useful species of Massachusetts, with accounts of their food habits, and a chapter on the means of attracting and protecting birds. Birds; Birds. UTILITY OF BIRDS IN NATURE. 9 The general fitness of the Crow is admitted by all. Un- doubtedly it has a useful work to perform in the world ; but a careful study of its food habits shows so many apparently harmful traits that it may well leave the investigator in some doubt as to the Crow's vatue in the general plan. Crows rob the nests of Robins, eating very m
. Useful birds and their protection. Containing brief descriptions of the more common and useful species of Massachusetts, with accounts of their food habits, and a chapter on the means of attracting and protecting birds. Birds; Birds. UTILITY OF BIRDS IN NATURE. 9 The general fitness of the Crow is admitted by all. Un- doubtedly it has a useful work to perform in the world ; but a careful study of its food habits shows so many apparently harmful traits that it may well leave the investigator in some doubt as to the Crow's vatue in the general plan. Crows rob the nests of Robins, eating very many eggs and young birds ; they therefore constitute a serious check on the in- crease of this species. Robins feed largely on common black beetles, called ground beetles (Carabidae), which run about on the ground, hiding under stones and other rubbish. As these beetles are not quick to fly by day, and are easily caught, they form a consid- erable part of the food of many ground- frequenting birds. But ground beetles feed, to a greater or less extent, on other insects. The question then arises, Is not the Robin doing harm in killing ground beetles, and does it not merit the destruc- tion of its eggs and young by the Crow? mg If the Robin's habit of eating these beetles beetle- is harmful, is not the Crow rendering a service by destroy- ing a bird so apparently destructive as the Robin ? Perhaps, if there were too many Robins, they might eat too many ground beetles, and thus become the indirect cause of the destruction of much vegetation, by saving the lives of the caterpillars and other harmful insects that the ground beetles, had they been left to themselves, might have Many ground beetles that are eaten by the Robin feed much on vegetable This makes these beetles doubly useful in one respect, for they can maintain their numbers 1 These questions can be answered only by one having a thorough knowledge of the food of our ground beetles, — a know
Size: 1286px × 1943px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherb, booksubjectbirds
