   Ravens - October 26, 2005 Jeff Schalau, County Director, Associate Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County The common raven (Corvus corax) is the largest of all songbirds and is thought by many to also be the smartest of all the birds. It has one of the broadest geographic ranges of all birds spanning across North America and Eurasia and occupies most major climate regions from the arctic to low deserts. Ravens are similar to crows in appearance, but are larger with longer, narrower wings, a wedge-shaped tail, and weigh about four times that of the crow. Ravens have a wide range of vocalizations and have been observed imitating various sounds from barking dogs to squeaky hinges. In flight, ravens make a “swish-swish” sound and often soar on flat wings similar to hawks. The raven is also an acrobatic flier making rolls and somersaults in the air and even flying upside down. Canyon rims are excellent places to observe ravens in flight. Raven nests are two to four feet in diameter constructed of twigs and branches lined with grass, moss, and fur. Following courtship, they remain paired for the year and possibly for life. Females lay eggs from mid-February to late May, depending on the latitude. The female incubates three to seven eggs for about three weeks. The male brings food to the nest for her. Both parents feed the young. After five or six weeks, the nestlings fledge. Fledglings may remain with their parents for another six months. Juvenile ravens are very curious while older ravens become more cautious over time. Zoologist Dr. Bernd Heinrich, observed ravens for four years in Maine and subsequently authored the book Ravens In Winter. One observation was that a juvenile raven would "recruit" others to a food source because, by sharing with others it gains "friends," from which it may gain a mate in the future due to its foraging abilities. While mated pairs are more-or-less anchored to their localized nesting area; low status juveniles can form wandering unmated groups. Ravens are opportunistic omnivores eating rodents, eggs, other bird’s nestlings, grain, and carrion. They also feed on garbage and waste near human settlements. Ravens are usually found solitarily or in pairs. However, when they find especially good food sources, such as carcasses of large mammals or abundant grain, they may form large communal roosts. Some roosts in the West have numbered over 2,000 birds and lasted for months. Some information sources say ravens were associated with bison and wolves on the grasslands of the Great Plains, but their range diminished with reductions in bison and wolf populations and cultivation of the prairies. Being intelligent and adaptable creatures, they modified their feeding habits to match the altered environment. Ravens also have a dubious reputation among farmers and wildlife managers. Farmers often blame ravens and crows for uprooting seedlings and other crop damage. Wildlife managers have documented ravens killing young of game and non-game species. In Prescott, ravens were observed by Arizona Game and Fish Department tormenting pronghorn fawns in the Willow Lake herd. Coyotes and domestic dogs were also to blame. It should be noted that this pronghorn herd has been isolated by development and the habitat severely degraded. While it may seem that retaliation is in order, ravens are a protected species and it is a federal crime to kill them or have them as pets without going through a permitting process. Finally, ravens are a common subject in folklore. They are often portrayed as tricksters, harbingers of the afterlife, and messengers of the gods. Among Native Americans of the Pacific Northwest, ravens are credited with creating humans, providing salmon for food, supplying water during drought, and bringing fire to humankind. In Edgar Allen Poe’s classic poem, The Raven visits a lonely soul and invokes haunting emotions of lost love, evil, and suffering as the raven calmly sits and speaks the word “nevermore.” Whatever your perspective, I hope you appreciate the many unique qualities of ravens. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |