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Description: |
ii, 56 pages including illustrations (including maps) tables, diagrams 23 cm |
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General Note: |
At head of title: United States Dept. of the Interior, Harold L. Ickes, secretary. Fish and wildlife service, Ira N. Gabrielson, director ... |
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Bibliography Note: |
Includes bibliographical references (pages 55-56). |
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Summary, Etc. Note: |
Abstract: The white-necked raven (Corvus cryptoleucus), a close relative of the common crow, is indigenous to southwestern United States. Because in parts of its range it has gained the same ill repute as acquired by the crow and magpie in their respective ranges, a 5-year detailed study of its activities and food habits was made, during which many field data were gathered, and the contents of 827 stomachs were analyzed. |
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Abstract: The omnivorous food habits of this raven often bring it into direct competition with farming interests, and frequently its depredations result in severe damage to crops, particularly to grain sorghums, corn, melons, peanuts, pecans, weak lambs, and poultry. To reduce these attacks and keep the losses at a minimum often is expensive and requires considerable work on the part of ranchers and farmers. On the other hand nearly half the raven's food is of animal origin and includes a wide assortment of insects, many of which are harmful to crops. Grasshoppers, weevils, May beetles, caterpillars, fly maggots, and like pests constitute a material part of the insect diet. Carrion is another important food of the raven, and its removal from the range is a definite aid to sanitation. |
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Abstract: When heavy raven concentrations occur, the crops must be protected. As effective control is impossible when natural food is abundant, it is generally necessary to resort of frightening measures until winter sets in and the food supply becomes low enough to insure control success. Various contrivances to scare the birds away may be placed in the fields, but the shotgun is without question the best frightening device. The most successful, selective and humane control measure is the use of large cage traps. As the need for control is usually local and varies by seasons, depending upon the crop situation, the soundest policy is to resort of it only when necessary and to take advantage of the bird's better attributes at all other times. |