In lab tests, they have shown a much higher density of neurons in their forebrains than primates do. They’ve shown levels of cognition that put them on par with the great apes. That’s proportionately much larger than a human’s three-pound brain, which accounts for 1.9 percent of overall weight.Ĭrows, ravens, and parrots have the biggest brain-to-body size ratios of all living bird species. The New Caledonian crow’s brain weighs 0.26 ounces and accounts for 2.7 percent of its overall weight. Proportionally, some crows’ brains are bigger than yours.Ĭrows are so smart and so good at improvising that some zoologists call them “ feathered apes” (that’s a compliment). The strategy seems to be working: two-thirds of the faux nests have been used. Made with non-conductive resin, the nests are placed on company towers high above the power lines, where the birds are unlikely to cause any trouble. One result was an epidemic of crow-caused blackouts in major cities: Between 20, the corvids stole almost 1400 fiber-optic cables from Tokyo power providers, and according to the Chubu electric company, crows are responsible for around 100 power failures per year in their facilities.Ĭhubu started installing artificial nests in 2004. Urban crows like to nest on electric transformers and will often use wire hangers or fiber-optic cables as building materials for their nests. Since the 1990s, crows have experienced a population boom in Japan, where delicious garbage is more plentiful than ever. Some studies suggest that the mass gathering is part of a survival strategy: The birds are learning about threats and seem hesitant to revisit any spot where they’ve encountered a dead crow, even if food is plentiful there. During this ritual, the live crows almost never touch the dead one, which rules scavenging out as a motive. The sight of a dead crow tends to attract a mob of a hundred or more live ones. Jesse Weinstein, Wikimedia Commons // CC BY-SA 3.0 When a crow dies, its neighbors may have a funeral.Ī spooky flock of crows roosting in a tree. ![]() And some birds become regular nest assistants, providing aid to their parents for over half a decade. One study found that 80 percent of American crow nests surveyed had a helping hand. Other services they can provide include bringing food to the parents or feeding their younger siblings directly. Juvenile birds are frequently seen defending their parents’ nest from predators. During the winter months, they’ll congregate with hundreds or even thousands of their peers to sleep together at night in a sprawling communal unit called a roost.Ī mated pair of crows might be lucky enough to receive chick-rearing help. American crows spend most of the year living in pairs (they usually mate for life) or small family groups. Like a lot of intelligent animals, most crows are quite social. Older crow siblings can help their parents raise newborn chicks. And the birds’ calls are different: crows emit a caw-caw call along with rattling and clicking sounds, while a raven’s is a croaking, deeper-pitched onk-onk. It also has a wedge-shaped tail compared the crow’s slightly rounded tail. The common raven is much larger, about the size of a red-tailed hawk. In the U.S., the American crow ( Corvus brachyrhynchos) and the common raven ( Corvus corax) are the most widespread corvids. To date, scientists have identified 40 species that are commonly called ravens, crows, rooks, and jackdaws. Members of the genus Corvus can be found on every continent except Antarctica and South America (although other close relatives live there). All crows and ravens belong to the same genus. Here are a few facts about these crafty corvids that might surprise you. But the birds are fascinating creatures, adaptable and brainy to an extent that’s almost scary. Farmers accuse crows of stealing crops and city dwellers consider them a nuisance. In many Western cultures, they’ve been associated with death, disease, and bad omens.
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