i ;8 



ANIMAL BIOLOGY 



destroyed. If crows or blackbirds are seen in numbers about 



cornfields, or if woodpeckers are noticed at work in an orchard, 

 it is perhaps not surprising that they 

 are accused of doing harm. Careful in- 

 vestigation, however, often shows that 

 they are actually destroying noxious in- 

 sects ; and also that even those which 

 do harm at one season may compensate 

 for it by eating insect pests at another. 

 Insects are eaten at all times by the 

 majority of land birds. During the 



breeding season most kinds subsist largely on this food, and rear 



their young exclusively upon it. 



Partridges. — Speaking of 13 birds which he shot, Dr. Judd says : 



These 13 had taken weed seed to the extent of 63 per cent of 



Fig. 323. — Head of Duck. 



FIG. 324. — JACANA. (Mexico, Southwest Texas, and Florida.) 

 Questions: What appears to be the use of such long toes? What peculiarity of wing? head? 



their food. Thirty-eight per cent was ragweed, 2 per cent tick 

 trefoil, partridge pea, and locust seeds, and 23 per cent seeds of 

 miscellaneous weeds. About 14 per cent of the quail's food for 



