There's more to these common black birds then meets the eye.
By Shawn Hayward
They perch outside your window in the early morning fog, their black eyes piercing the mist to boldly meet your gaze. They peck at your garbage and hop around your lawn looking for worms and other tasty treats. They go about their business oblivious to the stigma they carry in human society.
A lot of people don't like crows. They think they're devious, dirty or just plain evil. But crows aren't the villains people paint them to be - they're extremely smart animals that can even make great pets with the right care and patience.
Crows belong to the genus corvus, putting them in the same family of birds as ravens, jays and magpies. There are dozens of species of crows and they're found throughout the world: from the tropics to the deserts of Africa, to the forests of northern Canada. Crows are generally all black, but some species sport grey feathers. The raven looks a lot like a crow, but belongs to different species, and ravens are usually larger than the average crow.
When it comes to intelligence, the crow is on the top perch. Canadian researcher Louis Lefebvre found crows have the biggest IQs of any bird species. Not surprising, since they have one of the largest brains compared to body size, over five times larger than that of pigeons.
Lefebvre judged each species on the innovative ways they use tools and their environment to get food and other things they need. He documented more than 2,000 innovations among 500 different species of birds, and crows showed the most intelligence.
One species, the Japanese carrion crow, dropped nuts onto a city street so cars could crush them, then waited for the light to turn red and stop traffic so it could fly down and eat the pieces. Witnesses filmed another species in Israel using breadcrumbs to catch fish. It would place a crumb in the water, wait for a fish to take the bait, then scoop it up in its beak.
"Their intelligence level is more like on the level of a dog or higher level of cognition than we would associate with a bird," says Bill Montevecchi, a bird researcher at Memorial University. "They're so aware of their environment. You put your hand in your pocket. Most birds won't have any conceptions of that. Most crows I've had are watching to figure out what's in there or what you'll do next."
Crows' ability to adapt to the world around them comes from their human-like brains, according to Bill. The cortex is the centre for complex thinking, and most bird brains have very simple cortical regions. The cortex of a crow has many folds and fissures, making it more like a dolphin, primate or human brain than a bird's brain.
Super-smart crows have been seen guiding hunters to their prey with caws so they can share in the leftovers of the carcass. They can recognize opportunity and figure out how to take advantage of it.
The ebony fowl sharpens its skills shortly after leaving the nest, according to Bill.
"The young ones have a very open program," he says. "That means they potentially could make lots of mistakes. They don't have much fear. I think that's part of being intelligent. You have that exploratory behaviour. If you have the ability to make mistakes and learn from them, that's a really good strategy for being intelligent."
By trying new things, crows learn ways to get food your average bird wouldn't understand. For example, Bill once saw a crow dropping sticks on a seagull sitting on its nest, and when the seagull flew away, the crow ate the eggs.
"The raven or crow knew exactly what they were doing," says Bill. "The seagull was totally terrified, and the raven knew it was totally terrified."
Crows' ability to make and use tools puts them in a very elite group of organisms that includes humans, dolphins and primates.
"It seems to be a pretty high level of competence," says Bill. "We think about it in primates. It's a behaviour we see quite commonly (in them)."
A Crow to Call Your Own
Eight years ago Juliana Coffey was working at Memorial University when she found a fledgling crow that had fallen from its nest on top of the engineering building and broken its leg. Being a biologist and animal lover, she brought the crow home so her family could care for him.
The family didn't expect the crow to live very long, but an unusual diet seemed to help him thrive.
"At the time there was a spanworm problem," says Carole Anne. "We kept feeding him (spanworms) continually over the next couple days."
Juliana named the little crow Omar and kept him in a cardboard box for the first part of his life, before moving him to a large cage big enough for a Newfoundland dog. He slowly turned away from live food and began eating a combination of fruit, nuts and cat food.
Carole Anne had a cat and a dog at the time, and both animals quickly accepted Omar into the family.
"I have a picture of the dog, the crow and the cat all sitting side by side, all begging for food," she says. "They were quite chummy with each other. The crow would drag a piece of shoelace across the carpet and the cat would pounce on the end of it."
Omar liked the cat and dog so much he started to imitate their sounds. Carole Anne says he can fool people into thinking the dog or cat is in the next room - and that's not the end of his vocal abilities.
"They don't just make caws," says Carole Anne. "They have a lovely cacophony of sounds: warbles, chortles and trills; real soft sounds, not just these harsh sounds." Her crow will even sing on command and make a sound like a woodpecker if he feels threatened.
Anyone thinking of taking a crow as a pet should know they can be expensive and inconvenient guests, cautions Carole Anne. She takes Omar to the vet every six weeks to get his talons clipped and beak trimmed. He's an adult now but still very attached to the family. One time Carole Anne got a friend to look after Omar while she was away and the crow lost weight from the stress.
"We can't go away on a vacation unless we have a family member to look after him," says Carole Anne. "He recognizes all our family members. Anyone strange that comes in, he really gets spooked. He doesn't like other people."
Omar goes outside quite a bit but doesn't fly away. His leg is still damaged from the fall that brought him into Juliana's life, and landing is difficult. He interacts with other crows from the safety of the Coffey house, and the crows respond to him.
"They'll perch on the clothesline and watch him because they're very curious about him," says Carole Anne. "He'll caw a lot as they're coming. He chimes in with them."
Carole Anne says she's learned a lot about crows after having one in the house for the past eight years. Omar makes tools to wash himself, mimics the family pets and recognizes familiar people from strangers.
"Some people really hate crows," she says. "They think of them being bad luck. But once they meet Omar it changes their whole perspective on crows. They don't realize how intelligent they are."
Did you know?London's Legendary Ravens:
It might be their cold black eyes, or their harsh, piercing cry, but something definitely made humans think crows and ravens have supernatural powers.
According to an old English legend, the Tower of London will collapse and the monarchy with it if the ravens that inhabit the tower ever abandon it.
The ravens were almost kicked out of the Tower by Charles II in the 17th century after complaints by the royal astronomer that they were interfering with his observations. When Charles was told about the legend, though, he moved the observatory to Greenwich instead.
Ravens continue to lived in the Tower of London, where a guard (the "Ravenmaster") feeds and cares for the birds. He keeps 10 of them as pets, clipping their wings so they don't fly away and raising the young in his own home to build a relationship with them. The British government pays for their room and board.