- Explain key elements about the biology of crows important for their control.
- Understand federal laws and regulations restricting the control of crows.
- Explain options for the control of crows.
Crows are protected by the Migratory Bird Treaty Act. Under the Act, crows may be controlled without a federal permit when found “committing or about to commit depredations upon ornamental or shade trees, agricultural crops, livestock, or wildlife, or when concentrated in such numbers and manner to constitute a health hazard or other nuisance.”
States may require permits for the control of crows and may regulate the method of take. Federal guidelines permit states to establish regulations and hunting seasons. Regulations or interpretation of rules regarding depredation may vary among states, and state or local laws may prohibit certain activities for control, such as shooting or trapping. Check with local wildlife officials for specific rules and regulations before initiating control.
The American crow (Corvus brachyrhynchos, Figure 1) is the most common species of crow in North America. They often are confused with 3 other species of crow, the fish crow (C. ossifragus), northwestern crow (C. caurinus), and Mexican crow (C. imparatus). Two species of ravens also look similar to crows, the common or northern raven (C. corax) and Chihuahuan or white-necked raven (C. cryptoleucus).
American crows are easy to identify with their black plumage and relatively large size. They are 17 to 21 inches long and weigh about 1 pound. They are common in areas near people. Tales of their wit and intelligence are often noted. Males and females are similar in appearance.
Fish crows are smaller than American crows but appear alike in the field. Northwestern crows are smaller than American crows and Mexican crows are the smallest.
Common ravens are distinguished from crows by their larger size, call, wedge-shaped tail, and flight pattern that commonly includes soaring or gliding. In contrast, crows have a frequent steady wing-beat with little or no gliding. Chihuahuan ravens are smaller than common ravens, but larger than American crows. Chihuahuan ravens are distinguished from crows by their call, slightly wedge-shaped tail, and flight pattern that includes gliding. The white neck feathers are seldom visible in the field.
American crows are widely distributed in North America (Figure 2). They breed from Newfoundland and Manitoba south to Florida and Texas and throughout most of the West. During the fall, crows in the northern part of their range migrate and generally winter south of the Canada-US border. Fish crows primarily are found in the eastern and southeastern coastal US, but their range extends to the eastern edges of Oklahoma and Texas.
Northwestern crows occur in the northwestern US, along the coast from Washington to Alaska, and often forage along beaches. Mexican crows occur in south Texas, primarily during fall and winter. Common ravens are found from the foothills of the Rockies westward, north to Alaska, east across Canada and some northern US states,
Figure 2. Distribution of the American crow in North America. Image by Stephen M. Vantassel.
and locally in the Appalachian Mountains. Chihuahuan ravens occur in the Southwest, including portions of western Kansas, Colorado, Oklahoma, Texas, New Mexico, and Arizona.
Voice and Sounds
American crows vocalize with several calls, including a warning call, “caw, caw.” Crows can mimic sounds made by other birds and animals, and have been taught to mimic voices of humans. The call of fish crows is a short, nasal “ca,” “car,” or “ca-ha.” The calls of Mexican crows include a low, frog-like “gurr” or “croak” and a higher-pitched “creow.”
Tracks and Signs
The gregarious behavior of crows accompanied by frequent vocalizations allow for easy identification. Tracks may be found in soft soils (Figure 3).
Figure 3. Track of an American crow. Image by Dee Ebekka.