This article appeared in the JANUARY 1993 issue and is reprinted with permission from , a publication of The Washington Times Corporation, copyright (c) 1993.
January 1993, vol 8 (1): 243-253.
BIG, BLACK, AND BEAUTIFUL
Kevin J. McGowan
Contrary to popular misconceptions, American crows have many redeeming qualities.
People often have strong opinions about crows. Some are fond of them, perhaps because the crow's apparent intelligence makes it more humanlike than most other birds. Or perhaps it is because of the person's familiarity with a pet crow at some time in their life. Crows are frequently found or taken as nestlings and make very personable, if illegal, pets.
Most other people generally hate crows. The usual reasons given are that they are noisy, or that they kill little birds. Crows have had a bad reputation for a long time, being portrayed as evil despoilers of corn crops and the brazen tormentors of the poor scarecrow in the Wizard of Oz.
However, even when people are given the facts about the crow's place in the natural world and the small actual impact they have on agriculture or songbird populations, most people continue to cling to their negative impressions of crows. Similar negative feelings about the many different crow species can be found throughout the world. The factors that seem to have the greatest negative impact on people are the crows' appearance: big and black, ugly and evil-looking. (Actually, in the right light crows can be quite beautiful: glossy and iridescent purple.)
Being large and black, ravens and crows often figure prominently in the folklore and mythology of people throughout the world. Though occasionally they are portrayed as wise heroes, usually they are evil portents of misfortune. In much the same way the absence of legs makes the snake unappealing, the physical appearance of crows makes them unpopular. And, as if things were not bad enough, the crow has an ugly, coarse caw, despite being in the same avian order as nightingales, wrens, and mockingbirds.
At the end of the short winter day, crows roost in the treetops, converging there from as far away as 20 miles.
A winter gathering
American crows are most noticeable when the short winter day comes to an end. Streams of them can be seen flying high overhead, with a sense of purpose. Dozens of the large black birds converge on a single woodlot, filling it with their raucous cacophony. They are at a winter roost, where crows congregate from as far away as 20 miles. Crows that breed near the roost site mix with migrants from thousands of miles away.
What appears to be a small flock of birds may well be a cohesive family unit. Family ties that are created when young can last for years.
On the same winter day that 200 crows may be feeding together in a field of corn stubble, eight others may descend in a suburban backyard. While seven probe about the lawn for worms and grubs, one perches in a nearby tree and remains vigilant. What appears to be a typical small flock of birds is, in fact, a cohesive family unit. The group consists of a breeding pair and their offspring from the last three breeding seasons. The young from the previous years have remained with their parents and assisted in raising their brothers and sisters. They have fed the young in the nest, defended the nest, and one is now guarding the family while they forage. Some or all of the family may join the large roosting flock in the evening, or they may sleep on the territory they maintain throughout the year. Although crows are familiar birds throughout North America, few people are aware of the complicated lives these birds lead.
The American crow is the most widespread and familiar of the four species of crow found in North America. It ranges from the Atlantic coast to the Pacific, and from the southeastern edge of Alaska to the Gulf of Mexico, absent only from the deserts and treeless shortgrass prairies of the American West. Its genus name Corvus means crow, and the species name brachyrhynchos means "short beak," which it has, at least in comparison with its relative the raven.
Not a typical songbird
Crows are members of the avian order Passeriformes, which comprises the songbirds or perching birds, such as robins, cardinals, and sparrows. American crows differ in more ways from these familiar songbirds than by their lack of a song. One of the most marked differences is in their family life. Most small passerines set up and defend territories only in the breeding season and attract mates at that time. The fidelity of breeding pairs over years varies but is generally low and dependent upon previous success together. The young are dependent on the adults for only a few weeks. They then leave or are kicked out of the parental territory, and the parents go about raising another brood. The young and the parents may never see each other again.
In many regions crows are not migratory but remain in their territory year round, even in areas where winters are harsh.
American crows, at least in the southern and eastern parts of their range, maintain a territory year round, although they defend it less in winter. In the northern parts of their range, American crows are migratory and return to breeding sites after spending the winter in more southerly latitudes. Western American crows appear not to hold territories, but most still remain near their breeding sites throughout the year. American crows are long-lived birds (up to 30 years old), and do not begin to breed until they are at least 2 years old, often older. Breeding pairs remain together "for life," or until one becomes incapacitated.
The female crow usually lays five eggs, but rarely do all five hatchlings make it to maturity. The young are fed in the nest and for up to two months out of the nest.
Young crows remain in their nests for over one month and are fed by the adults for a month or two after they leave the nest. Consequently, breeding pairs can raise only one brood of young each year. In the nonmigratory populations young crows are not kicked out of the parental territory but remain with their parents throughout the first fall and winter. They often remain with their parents for several years, until they get a breeding opportunity of their own. While some of the young crows may leave the home territory intermittently during this time, they keep returning and interacting with their family.
During the breeding season some of the young nonbreeding crows in a family assist the breeding pair in a number of tasks. Young crows may help build the nest, feed the incubating female, feed nestlings and fledglings, remove fecal sacs produced by the nestlings, defend the nest against predators, and defend the territory against intruders. 0nly a handful of other bird species in North America exhibit similar behavior, and none is as widespread as the American crow.
Members of the genus Corvus, crows and ravens are found throughout the world. They are absent only from South America, Antarctica, and certain Pacific islands. Where they do occur they are likely to be familiar and common, with several species having become adapted to living near humans, depredating crops or feeding on refuse that is so abundant near human habitation.
Despite their resemblance in winter gregariousness and urban ubiquity to the introduced pest the European starling, crows are native to North America - native birds that have done well for themselves. At a time when there is often news of species endangered by human action, the crow stands out as an exception: a survivor. American crow populations are steady or increasing, and the species may even be expanding its range to the northwest into Alaska.
The crow has learned to cope successfully with the hazards of living near humans, despite still being hunted as a game bird in most states. The American crow is a bird of mixed habitats, preferring a mosaic of open areas and Woods. Originally rare in much of its range, the crow benefited from the clearing of the extensive North American forests. It also profited by the changes man wrought on the open prairies. As homesteaders moved across the prairies and planted trees to shelter their homes, crows took advantage of the new nesting sites and moved with them.
One way the crows have found of surviving with humans is by getting nearer to them rather than fleeing. Crows recently have begun to roost and nest in urban areas, perhaps to take advantage of laws prohibiting the discharge of firearms within city limits. A winter roost in the country would be vulnerable to hunters, while one in town is safe.
As scavengers, crows make use of any food source they can find, including dead animals along the highway and garbage. Crows are rapidly adapting to urban living and comfortably nest in backyard trees.
Reliable food sources are also available in urban areas. Plastic trash bags containing food scraps are regularly placed along the streets in residential neighborhoods. All a smart bird has to do is rip the bags open. scatter the trash, and eat the food. Many a suburban home owner blames stray dogs for the mess made by opportunistic crows. One of the reasons that crows can adapt to this urban life-style is that they naturally are scavengers, cleaning up the remains of animals that they did not kill.
In addition, they are omnivorous, eating many types of grains and fruits, and any animal they can catch. The eclectic crow will eat corn, road-killed opossum, baby mice, earthworms, sumac fruits, nestling birds, frogs, fish, grasshoppers, dead deer, or old french fries. Whatever is available is fine; they are not finicky.
Though maligned for ages, crows are a valuable part of our ecosystem, and with only a little education the public can better appreciate them.
While crows have adapted well to humans, humans continue to be troubled by crows. For centuries they have been shot as pests: vermin that kill chickens, destroy the nests and young of game birds and pluck up sprouting corn. Although crows can have significant effects on waterfowl nest success, their reputation for eating songbird eggs and young is probably overstated. The primary food resource of eastern crows in spring appears to be earthworms. Crows can cause considerable damage to a few isolated farms, but in fact, they may do more good than harm to agriculture. A recent study in southern Ontario, Canada, found that cornfields frequented by crows in winter have fewer problems with European corn borers in the next growing season than those not frequently visited by crows. The crows eat up significant numbers of the corn borer larvae overwintering in old corn stalks.
One thing is for sure: No matter how people feel, the crow is not going to disappear from the urban or rural scene. And with a better understanding of this amazingly adaptable and somewhat humanlike bird will come a more positive opinion of its place in our world.
Kevin J. McGowan is a research and curatorial associate in ecology and systematics at Cornell University. He has studied the social and reproductive biology of crows and jays in Florida and New York.
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