Dwight R. Platt

“ The availability of pellets and the ease of collecting them are obvious advantages. Under large roosts in winter the number that can be collected is almost unlimited. At other seasons, pellets are scarcer, but even so they usually are more available than stomachs.
The technique of pellet analysis is more easily applied to a study of the yearly diet than is the technique of stomach analysis. The crow is euryphagous and, as shown by this study, the diets of crows a few miles apart may differ. ”

“ In both popular accounts and scientific studies, the economic significance of the consumption of weed seeds such as those of sunflowers by birds often has been interpreted in an oversimplified manner. It has been assumed that if crows eat several million sunflower seeds in the winter, the sunflowers growing in the farmers' fields the next year will have been reduced by the same number. ”

“ Crows are beneficial to the farmer insofar as they control the populations of scarabaeids and other non-predaceous beetles. However, destruction of predaceous beetles is harmful to the farmers' best interests.
Grasshoppers, second only to beetles in the insect component of the diet, are among the most destructive insects in Kansas. Eggs laid in autumn overwinter and hatch the next summer, from April to August, depending upon the species. ”

“ Predators of this type tend to maintain stability in a community in contrast to the violent oscillations often caused by a more stenophagous predator. This study indicates that in south-central Kansas crows help to stabilize the populations of grasshoppers, ground-dwelling beetles both predaceous and non-predaceous, and probably those of other types of insects whose soil dwelling larvae are subject to predation during summer plowing. ”

“ However, in the western part of the study area, they constituted a smaller part of the diet.
Predation upon grasshoppers, especially in summer and early autumn, benefits the farmer by helping to stabilize populations of grasshoppers. However, when grasshopper consumption was highest, in early October, many of those eaten probably already had completed their breeding cycle, and their consumption was hence of little significance economically or ecologically. ”

“ The yearly diet of the crow was studied from December, 1952, to February, 1954, in Harvey County and the northeastern townships of Reno County, in south-central Kansas. In the United States much attention has been devoted previously to the food taken by the crow because it is of economic importance. ”

“ Wild fruits such as grape and pokeberry also showed up in trace amounts. Elsewhere, investigators have found wild fruit forming a major source of food in winter. However, it was not readily available in this area. ”