By Tom Dennis
The American Crow, Corvus brachyrhynchos, is one of our most misunderstood creatures, however, it continues to survive and thrive despite being disliked by many people. There have been efforts to eradicate this handsome bird in the past and even today this bird, that is protected by the Migratory Bird Act, is hunted strictly for sport in some areas and is often the subject of debate over its value, largely because it is very susceptible to death from West Nile Virus. The scientific species epithet brachyrhynchos, literally means short-billed and is from the Ancient Greek (Anglicized) brachy “short” and rhynchos “billed”. Please read on to learn why we need American Crows in the world and what makes them one of my favorite birds.
As you are well aware, American Crows are completely black with the exception of their eyes which are dark brown in mature adults. The wings and back show a purple-black iridescence in the sunlight and they have a heavy, multi-purpose bill. They can be distinguished from their “cousins”, Common Ravens, during flight by their fan-shaped tail. Ravens hold their tails in a spade shape during flight. The usual “caaw, caaw” call of the American Crow also helps in identification as the Raven makes a “croaking” call and the Fish Crow (a smaller bird) makes a nasal sounding “cah”. They are large birds varying in height from 16 to 32 inches and in mass from 11 to 21 ounces. The American Crow is also the only one of these birds found in our area and in fact, it would be extremely rare to find a Common Raven in the lower peninsula of Michigan except in the Northern-most “troll” counties (that’s under-the-bridge in case you didn’t know). American Crows are year-round residents of most of the continental United States and they are typically summer-only residents in most of Canada.
They are one of the most intelligent birds known to exist and one of few species documented as using simple tools. In addition to their typical vocalizations, they also mimic other birds and animals, including human voices. They can count, work out solutions to simple problems and they are fond of collecting shiny objects like keys, rings, and other trinkets which they will openly thieve from us. Family life is important to crows and they often live with multiple generations that work, learn, and dine together just like good, old-fashioned human families! The family joins together in nest-building activities, usually in tall trees with nests up to 100 feet in the air and constructed of sticks and twigs. They are very adaptable in many ways and will nest on the ground if necessary. They occupy almost any habitat from urban to wild and being non-selective and advantageous omnivores they will clean up landfill dumps as well as the farmer’s fields. Like many birds, they are especially fond of insects and thereby benefit us greatly. You may want to replace that scarecrow in your garden with a sign advertising “juicy insects available here”. Crows also join Northern Flickers in “anting” behavior during which they stand on an anthill and let the ants discharge formic acid. This not only helps the crows rid their bodies of parasites, it also renders the ants quite palatable.
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Because American Crows are extremely sensitive to West Nile Virus, they also serve mankind as a bio-indicator warning species. This mosquito-borne, African virus was accidentally introduced to North America in 1999 and causes encephalitis in humans and our livestock. It is especially deadly to crows and their population has dropped by an average of 45% since its introduction with local population losses of up to 72% in a single season. Crows help us locate this disease when unusually large die-off occurs and it’s important to understand the West Nile Virus isn’t transmitted from Crows to man or other animals. The next time you see or hear a crow, I trust you will better appreciate their existence and count yourself blessed to have them on your yard list!
If you wish to learn more about birds you are welcome to attend Blue Water Audubon meetings held at The Point, 5085 Lakeshore Rd, in Fort Gratiot. Our first meeting of the season will be held October 4th starting at 6:45 PM. Please visit our Facebook page, “Blue Water Audubon Society”, and be sure to friend us.
Tom Dennis is a free-lance writer, passionate birder, zoologist, creation scientist, gardener, and naturalist.