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American Crows University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln The Handbook: Prevention and Control of Wildlife Damage Management, Internet Center Wildlife Damage for 1-1-1994 AMERICAN CROWS Ron J. Johnson University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/icwdmhandbook Part of the Environmental Sciences Commons Johnson, Ron J., "AMERICAN CROWS" (1994). The Handbook: Prevention and Control of Wildlife Damage. 60. https://digitalcommons.unl.edu/icwdmhandbook/60 This Article is brought to you for free and open access by the Wildlife Damage Management, Internet Center for at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in The Handbook: Prevention and Control of Wildlife Damage by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Ron J. Johnson Extension Wildlife Specialist Department of Forestry, Fisheries AMERICAN CROWS and Wildlife University of Nebraska Lincoln, Nebraska 68583-0819 Fig. 1. American crow, Corvus brachyrhynchos (also called the common crow or eastern crow) Damage Prevention and Frightening Trapping Control Methods Use with roosts, crops, and some other Check laws before trapping. situations. Frightening devices Australian crow decoy traps may Exclusion include recorded distress or alarm be useful near a high-value crop or calls, pyrotechnics, various sound- other areas where a resident Netting to exclude crows from high- producing devices, chemical population is causing damage. value crops or small areas. frightening agents (Avitrol®), lights, Proper care of traps and decoy Protect ripening corn in gardens by bright objects, high-pressure water birds is necessary. covering each ear with a paper cup spray, and, where appropriate, Capture single crows uninjured in size or sack after the silk has turned shotguns. No. 0 or No. 1 steel traps that have brown. Repellents the jaws wrapped with cloth or rub- ber. Widely-spaced lines or wires placed None are registered. around sites needing protection Shooting and Hunting may have some efficacy in repelling Toxicants Helpful as a dispersal or frightening crows, but further study is needed. None are registered technique but generally not effective Cultural Methods in reducing overall crow numbers. Alternate or decoy foods; example: Crows may be hunted during open scatter whole corn, preferably seasons. Check with your state softened by water, through a field wildlife agency for local restrictions. to protect newly planted corn seedlings. PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994 Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska - Lincoln United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control E-33 Great Plains Agricultural Council Wildlife Committee Identification quent steady wing-beat with little or ing grasshoppers, beetles, beetle larvae no gliding. (white grubs, wireworms), caterpillars, spiders, millipedes, dead fish, frogs, The American crow (Fig. 1) is one of Chihuahuan ravens occur in the South- salamanders, snakes, eggs and young America’s best-known birds. Males west, including portions of western of birds, and carrion such as traffic- and females are outwardly alike. Their Kansas, Colorado, Oklahoma, Texas, killed animals. The remainder of the large size (17 to 21 inches [43 to 53 cm] New Mexico, and Arizona and rarely crow’s diet consists of vegetable or long), completely coal-black plumage, in south-central Nebraska. This raven, plant matter. Corn is the principal food and familiar “caw caw” sound make which is smaller than the common item in this category, much of it them easy to identify. They are fairly raven and somewhat larger than the obtained from fields after harvest. common in areas near people, and American crow, can be distinguished Crows also consume acorns, various tales of their wit and intelligence have from the crow by its call, slightly wild and cultivated fruits, water- been noted in many stories. wedge-shaped tail, and flight pattern melon, wheat, sorghum, peanuts, that includes gliding. The white neck Three other crows occur in the conti- pecans, garbage, and miscellaneous feathers, which account for its other nental United States, the fish crow other items. (Corvus ossifragus), the northwestern name, are seldom visible in the field. crow (Corvus caurinus), and the Mexi- General Biology, can crow (Corvus imparatus). Fish Range crows are primarily inhabitants of the Reproduction, and eastern and southeastern coastal Behavior United States, but their range extends American crows are widely distrib- uted over much of North America. into the eastern edges of Oklahoma Crows are among the most intelligent and Texas. Fish crows are somewhat They breed from Newfoundland and Manitoba southward to Florida and of birds. Experiments indicate that smaller than American crows, but in American crows can count to three or the field they appear much alike. They Texas, and throughout the West, except in the drier southwestern por- four, are good at solving puzzles, have can be distinguished, however, by good memories, employ a diverse and their calls — the fish crow call is a tions. During fall, crows in the north- ern parts of their range migrate behaviorally complex range of vocal- short, nasal “ca,” “car,” or “ca-ha.” izations, and quickly learn to associate Northwestern crows, as their name southward and generally winter south of the Canada-US border. various noises and symbols with food. implies, occur in the northwest along One report describes an American the coastal strip from Washington to crow that dropped palm nuts Alaska. They are most often seen for- Habitat (Washingtonia sp.) onto a residential aging along beaches. Northwestern street, then waited for passing automo- crows are smaller than American American crows do best in a mixture biles to crack them. Crows are keen crows, but in Washington state these of open fields where food can be found and wary birds. Consider the number two species may hybridize. Mexican and woodlots where there are trees for of crows that scavenge along high- crows occur in south Texas (Browns- nesting and roosting. They commonly ways; how many have you seen hit by ville area) primarily during fall and use woodlots, wooded areas along autos? Crows can mimic sounds made winter and are fairly small for crows. streams and rivers, farmlands, by other birds and animals and have Their voice is a low froglike “gurr” or orchards, parks, and suburban areas. been taught to mimic the human voice. “croak” or, in some areas, a higher- Winter roosting concentrations of The myth that splitting the tongue pitched “creow.” crows occur in areas that have favor- allows a crow to talk better, however, Ravens are similar to crows in appear- able roost sites and abundant food. is not true and is needlessly cruel. ance. Two species occur in the conti- Crows often post a sentinel while feed- nental United States, the common or Food Habits ing. Although studies indicate that the northern raven (Corvus corax) and sentinel may be part of a family group, Chihuahuan or white-necked raven Crows are omnivorous, eating almost unrelated crows and other birds in the (Corvus cryptoleucus). The common anything, and they readily adapt food area likely benefit from the sentinel’s raven is found from the foothills of the habits to changing seasons and avail- presence. Rockies westward, northward to able food supply. They belong to a Alaska and eastward across Canada Crows begin nesting in early spring select group of birds that appear and some northern U.S. states, and lo- (February to May, with southern nests equally adept at live hunting, pirating, cally in the Appalachian mountains. starting earlier than northern ones) and scavenging. Studies show that Common ravens can be distinguished and build a nest of twigs, sticks, and crows consume over 600 different food from crows by their larger size, call, coarse stems. Crow pairs appear to items. wedge-shaped tail, and flight pattern remain together throughout the year, that commonly includes soaring or About one-third of the crow’s annual at least in nonmigratory populations, gliding. In contrast, crows have a fre- diet consists of animal matter, includ- and pairs or pair bonds are likely E-34 maintained even within large winter over large areas to feed during the was rural and relatively wary of migratory flocks. The nest, which is day. Crows may commonly fly 6 to 12 people. Will crows that are hatched in lined with shredded bark, feathers, miles (10 to 20 km) outward from a urban areas be habituated to people to grass, cloth, and string, is usually built roost each day to feed. such an extent that they will be more 18 to 60 feet (5 to 18 m) above ground difficult than their rural counterparts Recent radio-telemetry studies indicate in oaks, pines, cottonwoods, or other to disperse from problem sites? that roosting crows may have two dis- trees. Where there are few trees, crows Understanding such factors may lead tinct daily movement patterns. Some may nest on the ground or on the to better options for managing crows fly each day to a stable territory, called crossbars of telephone poles. The aver- in ways compatible with the needs of a diurnal activity center, which is age clutch is 4 to 6 eggs that hatch in people. maintained by four or five birds about 18 days. Young fledge in about throughout the winter and apparently 30 days. Usually there is 1 brood per then used as a nesting site in spring. Damage and Damage year, but in some southern areas there Although these stable groups of crows Identification may be 2 broods. Both sexes help build may stop at superabundant food the nest and feed the young, and occa- sources such as landfills, individuals Complaints associated with crow sionally offspring that are 1 or more within the groups typically fly differ- damage to agriculture were more com- years old (nest associates) help with ent routes and make different stops.
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