Ravens and Crows

Common Raven (Corvus corax)
Chihuahuan Raven (Corvus cryptoleucus)
American Crow (Corvus brachyrhynchos)

by Jay Sharp

One of the fabled ravens at the Tower of London. I made the picture about 20 years ago.

For some strange reason, ravens and crows have long played a prominent role across the landscape of the human imagination. It’s hard to understand why. Unlike the bald eagle, which soars elegantly above our heads, ravens and crows often fly acrobatically, much like many teenagers driving the family car. Unlike the American goldfinch, the Bullock’s oriole or the vermilion flycatcher, which sport exciting splashy colors and patterns, ravens and crows come in one basic color—solid ebony, morbidly black. Unlike the mockingbird or the curve-billed thrasher, which perform a wide repertoire of cheerful songs, ravens and crows usually just offer variations on a single coarse note: caw, caw, caw, caw. Unlike the white-winged dove or the Gambel’s quail, which feed primly on seeds and fruit, ravens and crows often feed greedily on carrion left beside a roadway or on food scraps scavenged from human trash. In spite of their loopy flight, gloomy color, raspy voices and gross feeding habits, ravens and crows often star in folk tales, old beliefs and literature.

 

Raven and Crow Tales

For centuries, said Samantha Fleming in White Dragon, ravens and crows “have had a special place in the mythology of various cultures.”

Puebloan peoples, as Charles F. Lummis said in his Pueblo Indian Folk-Stories, tell the story of crows dancing and singing: “Alas, Mama! You are shaking, you are shaking!” while they trick an ancient enemy, the coyote, into ending the life of his own mama.

The English long believed that if the fabled ravens of the Tower of London should depart, “the Crown will fall and Britain with it.” The English now sniff that they are above such a silly superstition, but in addition to the wild population at the Tower, they have kept a captive cadre of ravens since the 17th century. Just in case.

American poet Edgar Allen Poe, mourning for his lost love, spoke of a raven – a “grim, ungainly, ghastly, gaunt, and ominous bird of yore,” – that flew into his chambers, lit on a pallid bust, and cast its bleak shadow on the floor. Given the symbolism of the raven, Poe gave up hope that he would somehow ever recover his soul. “Nevermore,” he said mournfully and famously.

Another poet, whose nationality, state, city, address and name I’ve sworn to keep secret, penned the following:

There was an old crow that so constantly squabbled
His friends all thought that he should be throttled.
They met here of late,
Decided his fate,
And that’s how in bond he came to be bottled.

(Poets, of course, always “pen” their works, they never just write them.)

Distinguishing Features

In the Southwest, we have two species of ravens—the common raven (Corvus corax) and the Chihuahuan raven (Corvus cryptoleucus); and we have one species of crow—the American crow (Corvus brachyrhynchos).

A pair of Chihuahuan ravens beside an icy puddle in a shopping center parking lot.

All three birds, relatively large, have iridescent black plumage, black legs and feet, and black bills. The differences between them become most apparent when they are compared side by side. The typical adult common raven, the largest of the three, measures about two feet from the tip of its bill to the tip of its tail; the adult Chihuahuan raven, a little over a foot and a half; and the adult American crow, almost a foot and a half. The ravens have somewhat lankier bodies than the crow; they have heavier, slightly hooked upper bills, more developed throat hackles and wedge-shaped tails. The Chihuahuan raven has neck feathers with white bases, which sometimes may be seen if it fluffs its feathers or a wind lifts its feathers. The crow has a smaller bill, smoother throat hackles and a more rounded-off tail; it also has proportionally broader wings.

Range and Habitat

The common raven, said W. I. Boarman and B. Heinrich, Birds of North America Online, “is geographically and ecologically one of the most widespread naturally occurring birds in the world. It is distributed throughout major portions of North America, Europe, Asia, and North Africa, and in all terrestrial biomes except tropical rain forests.”

The Chihuahuan raven, according to the eBird internet site, ranges across most of northern Mexico up through southern and eastern New Mexico, southwestern Arizona, western Texas, western Oklahoma, southwestern Kansas and eastern Colorado.

The American crow, say N. A. Verbeek and C. Caffrey, Birds of North America Online, occurs across most of the United States (excepting the desert regions), from the Pacific to the Atlantic, and across the southern half of Canada.

In New Mexico, said Stan Tekiela, Birds of New Mexico Field Guide, the common raven occurs throughout the state, typically preferring the higher, contoured elevations with scattered woodlands and human structures. The Chihuahuan raven holds residence primarily in the southern and eastern parts of the state, favoring the lower grass- and shrublands and cityscapes (especially the local landfills). The American crow has made its home in the more northern part of the state, where it frequents open, broken habitats with scattered trees as well as open fields and cityscapes.

 

Behavior and Life Cycle

Highly gregarious, adaptable and resourceful, the ravens and the crow typically roost and feed in scattered flocks, sometimes numbering hundreds or thousands. Typically, they migrate only short distances with a change of seasons or variability of food sources. They may welcome newcomers to a flock, leading them to food windfalls. They may attack, or “mob,” in large numbers, a would-be predator to protect the flock or nestlings or fledglings. The young birds may play games such as tug-of-war and king-of-the-hill. Apparently just for fun, they may drop and catch objects in midflight or snitch and cache shiny and inedible objects in secret places. (Many years ago, my grandmother’s pet American crow stole her car keys, which she found days later in the downspout of her house gutter.) The birds may attack intruders of the same species, with fights sometimes becoming vicious, even deadly. A common raven may yank the tail of a predator, perhaps just for the fun of watching it react. The bird has been known to peck at the tail of a dog, and if gets away with that, it will peck at the nose of the pooch.

A single Chihuahuan raven in a shopping center parking lot.

Opportunistic and omnivorous, the ravens and crows feed primarily on the most abundant food source available at the season and place. This could include a broad range of insects, arachnids (e.g. spiders, scorpions), reptiles, small birds, small mammals, pilfered eggs, grains and fruits as well as carrion and human refuse. They have been known to peck at the eyes and noses of newborn calves and lambs, taking advantage of the softer tissues. The birds may team up to attack prey, trail large predators to scavenge leftovers, search highways to find roadkill, or follow farm machinery to catch flushed rodents. In one instance, said Boarman and Heinrich, two common ravens jumped a cat that had just captured a mouse. One of the ravens attacked the cat, causing it to drop its prey. The other raven snatched up the mouse and flew away. Crows, say Verbeek and Caffrey, pluck ticks while walking over the bodies of feral hogs and domestic cattle. When times are lean and competition high, the birds may cache food for later consumption.

Throughout the year, the bird spends substantial time resting, preening, sunning and just plain loafing. It may bathe in shallow waters, sprinklers and even fluffy snows, preening extensively after its bath. It may post itself near an ant bed, allowing the insects to crawl through its feathers, leaving a blanket of formic acid—a natural pesticide that eliminates parasites. After some moments, the bird shakes and picks the ants off, casting the insects aside.

In the spring, when breeding season arrives, raven and crow pairs mate and bond for the year and perhaps for life. During courtship, the birds may preen each other’s head feathers and gently clasp each other’s bills. The ravens may engage in acrobatic flight, showing off, trying to impress a prospective partner. The male and female may spread their wings and tails and fluff their feathers. In the common raven’s version of a lovers’ serenade, the two partners make gurgling, choking and knocking sounds. After mating, a pair turns to homemaking, which often becomes a family affair, with two or three “helpers” – often progeny from the previous season’s hatch – contributing to the raising of the young.

Typically, the birds build their nest on a solid platform such as the fork of a tree, the cross arms of a power pole or, sometimes, in the case of the common raven, on a ledge or crack in a cliff face. It appears that the male hauls most of the construction material to the nest site, and the female builds the nest, which she will make sturdy because she may use it again in coming years. First, she braids small branches and twigs and sometimes even bone or wire into a rough bowl shape spanning a foot and a half to several feet in diameter. Then, she lines her nest with whatever softer materials may be available—grasses, shredded bark, leaves, moss, animal fur, sheep wool, mud and maybe even rags or paper. The Chihuahuan raven female, said J. C. Bednarz and R. J. Raitt, Birds of North America Online, “molds a deep cup with her breast by pushing, prodding, and pounding movements…” The lined cup may span a foot in diameter and measure a few inches in depth.

Within a few days after she finishes her nest, the female lays five or six generally oval-shaped greenish-colored eggs over a period of several days. This will likely be her only brood of the year. While the female takes the primary responsibility of incubating her eggs, the male guards the nest from predators, feeds the female on her nest, and may even incubate the eggs for brief periods.

After about three weeks, the eggs begin to hatch, probably in the sequence in which they were laid, over a period of a few days. New hatchlings are born blind and helpless, covered with a slight down. While the female carries most responsibility for brooding the newborn, the male and, now the helpers as well, fetch food, typically insects, grains, carrion and food scraps for the female and the new arrivals. Sometimes, the male and the helpers dip the food in water to make it softer and easier for the nestlings to swallow.

Within a couple of weeks, the young have opened their eyes and begun sprouting feathers, looking, suggested one author, much like miniature gargoyles. Within four or five weeks, they have feathered fully, and they have become active, moving around the nest, stretching their wings. Soon, they begin short flights, but they remain near the nest for several more days as they perfect their skills. Over several weeks, as they develop the ability to take care of themselves, they stay in the vicinity of the nest still begging their parents and the helpers for food. After a couple of months, they may leave to join a flock, but some may return the following year to serve their turn as helpers in raising their parents’ next brood.

The raven or crow reaches sexual maturity at about three years of age. With good luck, the bird may live in the wild for four to six years, according to the Critter Control Internet site. In one instance, a banded wild crow reportedly lived for 29 years.

Life’s Perils

The International Union for Conservation of Nature and Natural Resources rates the survival of all three of the species to be of “Least Concern.” The IUCN points out that the three all occupy an “extremely large range;” their populations range from “very large” to “extremely large;” and generally, their population trends vary from “stable” to “increasing.” Still, in some parts of their range, according to Boarman and Heinrich, the birds have been eradicated to a large extent because they have been considered pests, and, in some instances, reintroduction programs have been implemented. The birds – especially their eggs, nestlings and fledglings – can also fall to a number of predators such as coyotes, raccoons, hawks, owls and snakes.

Intelligence

Ravens and crows, naturalists believe, belong at the top of any ranking of the most intelligent birds. Relative to their size, they have the largest brains of any of the birds.

A study in 2004, said James Owen, reporting for National Geographic News, “suggests their cognitive abilities are a match for primates such as chimpanzees and gorillas.”

According to the NATURE internet site, “…ravens achieve mastery and possess manipulative powers over other creatures in their domain, often letting others do work for them. For example, ravens will call wolves and coyotes to prospective meals so they can expose the carcass and make the meat accessible to the birds. In addition, ravens will show their true scavenger colors by waiting for other birds with specialized foraging skills to make a catch and then cunningly seize the defeated prey for themselves.”

 

 

The American crow has been known to manufacture and use tools—a capability once attributed only to man and other primates. One wild crow, said Verbeek and Caffrey, “modified a piece of wood by pecking at it and then used it to probe a hole in a fence post…”

A winter flock of American crows (along with a few sandhill cranes and other birds)
in a field near the Bosque del Apache, in central New Mexico.

Raven & Crow Facts

• According to Boarman and Heinrich, the common raven engages in aerobatics, perhaps to declare dominance or impress a mate. In mid-flight, it may make a half roll or a full roll or even, occasionally, two rolls. It has even been observed flying upside down for more than half a mile.
• Given a transitory food supply and significant competition, an experienced common raven, said Boarman and Heinrich, may carry meat several miles to a location where it will cache and hide its booty.
• In selected areas within their range, Chihuahuan ravens may gather in flocks numbering as many as 50,000 birds during the winter.
• City-bred American crows, according to the National Geographic News, may scatter hard-shelled nuts on a street, waiting for automobiles to run over them and crack them, allowing access to the nut meat. “They do this at traffic light crossings, waiting patiently with human pedestrians for a red light before retrieving their prize.”
• The crows may also kill prey or crack open nuts by dropping them from a height onto a hard surface, said Verbeek and Caffrey.
• Where food is exceptionally abundant – for instance, in some places in the southern plains – American crows may gather in roosts of more than 2,000,000 birds, according to Verbeek and Caffrey. The birds may use roosts year after year. At one site in the northeast, they have roosted at the same site for more than a century.
  

 

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