26 BULLETIN 621, U. S. DEPARTMENT OP AGRICULTURE. 



and practically all flying insects, among which are many of the most 

 noxious pests, seldom come within their reach. The exact status of 

 these spiders, so abundant in some parts of the western prairie coun- 

 try, is as yet not fully understood. 



CRUSTACEANS. 



Stomach examination of adult crows showed that crustaceans con- 

 stituted 1.17 per cent of the yearly food. By far the largest propor- 

 tion of this consisted of crawfish, which were present in 150 of the 

 173 stomachs in which crustaceans were found. They were eaten in 

 every month, but were taken in largest quantities in March and 

 April, when they comprised over 3 per cent of the stomach contents. 

 Birds collected in southern States had eaten much more of this food 

 than their northern relatives. In fact, a series of "108 stomachs col- 

 lected in the Gulf and South Atlantic States gave a percentage of 

 7.40, over twice the proportion recorded for the full series of 1,340 

 adult birds collected throughout the country. A few birds had fed 

 almost exclusively upon these pests, while series of stomachs secured 

 in areas where crawfish were plentiful indicated that this food was 

 sought quite systematically, as nearly every bird had partaken of it. 

 This work is especially noteworthy in view of the injury these crusta- 

 ceans inflict upon corn and cotton in some sections of the South and 

 the damage which is sometimes done to dikes by their tunneling. 



Crustaceans other than crawfish were eaten in only small quanti- 

 ties. These were creatures of no special economic importance, as sow- 

 bugs {Armadillidium- sp.), found commonly in damp cellars and 

 under rotten logs, a few small amphipods, and, in one stomach, a 

 sandbug (Emerita talpoida). A few other unidentified crustacean 

 remains may have been of marine origin and were perhaps picked up 

 on the beach at low tide. 



MOLLUSKS AND OTHER AQUATIC INVERTEBRATES. 



The crow is a persistent feeder along lake shores and river banks, 

 where it picks up a considerable amount of aquatic food. The sea- 

 shore also, with its ebbing tide exposing daily an ample supply of 

 marine forms, is a common feeding ground of crows which roost or 

 nest for some miles inland. The latter locality is an especially favor- 

 ite one for the birds gathered along the Atlantic coast during the 

 winter months. In these situations mollusks of many kinds fre- 

 quently enter into the crow's diet. Remains of aquatic and land shells 

 were found, in stomachs throughout the year, though in bulk they 

 compose but a small proportion of the bird's food (0.31 per cent), 

 and in no month does the quantity exceed 1 per cent. This part of the 

 crow's fare can be considered as only of a neutral nature. 



