A crow knows more than you think. I’m not saying all crows are smarter than all humans, that would be preposterous. However a case could be made that some crows are smarter than most humans. First I’ll go over the basic facts about crows and ravens then build up to intelligence review. Rooks are slightly smaller than crows but I’ll skip further comparisons partly for brevity and partly because there are no Rooks in America.
It is staggering how much information there is on the web about crows. I’ve condensed the information as much as possible to summarize this fantastic creature.
Crows and ravens are members of the genus Corvus and the family Corvidae, but generally called “corvids"
Corvids occur in most climates
The sexes are very similar in color and size.Most corvids do not migrate unless there is a shortage of food.
The largest corvids are the ravens which average 3.1 lbs in weight.
common raven averages 25 inches (63 cm) in length and weigh 1.5 to 4.4 lb.
Corvids are self-aware in mirror tests
Like other corvids, ravens can mimic sounds from their environment, including human speech.
Crows have excellent vision, roughly five times better than humans, and a highly developed ability to distinguish colors.
Common crows/ravens are omnivorous and highly opportunistic regarding diet.
Crows are much smaller than Ravens - about half the size.
Crow beaks are small and sharp, raven beaks are larger and sometimes have a hook at the end.
Wingspan of crow is 32” to 38”, raven is 46” to 54”
Raven tails are fan or diamond shape, a crow’s is more cut off.
Ravens have thick throat hackles - crows don’t.
Crows caw and ravens cronk.
Crows flap more, while ravens soar.
When a crow lands they often bob but ravens do not. Ravens are more regal in stance.
Note a juvenile raven does appear very similar to a crow.
Most people just describe crows as “black”. However in bright sunlight, the reflective qualities of crow feathers produce a surprisingly brilliant array of deep metallic blues and greens.
As a crow ages their eye color changes. As nestlings their eyes start blue. Juveniles have chestnut brown eyes. Adults eyes are pure white.
A group of magpies is known as a “parliament”.
A group of ravens is known as either a “conspiracy of ravens” or "unkindness of ravens”.
A group of crows is known as a “murder of crows”.
Crows in captivity give their owners names - distinct sounds they use only for that single person.
Crows have actually murdered each other.
When a crow dies, other crows give a funeral.
Some Native Americans, such as the Haida, believed that a raven created the earth and despite being a trickster spirit, ravens were popular on totems, credited with creating man, and considered responsible for placing the Sun in the sky.
Likewise in Tlingit culture, raven was both a trickster and creator god. Related beliefs are widespread among the peoples of Siberia and northeast Asia. The Kamchatka Peninsula, for example, was supposed to have been created by the raven god Kutkh. There are several references to common ravens in the Old Testament of the Bible and it is an aspect of Mahakala in Bhutanese mythology
In Roman mythology these two birds are usually paired together and said to be the sacred bird and messenger of Apollo, the Roman god of prophecy.
The god Odin from Norse mythology was attended by Huginn and Muninn, two ravens who whispered news into his ears. These ravens were named Huginn (from the Old Norse for "thought") and Muninn (Old Norse for "memory" or "mind”).
The 6th century BC Greek scribe Aesop featured corvids as intelligent antagonists in many fables. Later, in western literature, popularized by American poet Edgar Allan Poe’s work “The Raven", the common raven becomes a symbol of the main character's descent into madness.
The Celtic peoples strongly associated corvids with war, death and the battlefield. According to Danish folklore recorded in the late 1800s, when a king or chieftain was killed in battle and not found and buried, ravens came and ate him. The ravens became valravne. The valravne that ate the king's heart gained human knowledge and could perform great malicious acts, could lead people astray, had superhuman powers, and were "terrible animals”.
In Sweden, ravens are known as the ghosts of murdered people, and in Germany as the souls of the damned.
A crow knows how to play! Juvenile ravens are among the most playful of bird species. They have been observed to slide down snowbanks, use lids as sleds, and use bark as a surf board for aerial maneuvers. They even engage in games with other species, such as playing catch-me-if-you-can with wolves, otters and dogs. Common ravens are known for spectacular aerobatic displays, such as flying in loops or interlocking talons with each other in flight.
They are also one of only a few wild animals who make their own toys. For example they break off twigs to play with socially.
Ravens and many species of corvids mate for life; all corvids have an extremely strong partner bond. Of course being known as tricksters there is an occasional “outside copulation”… but overall they are dedicated to their spouses and offspring. Males and females together build large nests together in trees or on ledges. The male will also feed the female during incubation. Both parents of a corvid pair care for the offspring. When babies are in the nest crows are renowned for being overly protective of the area. In fact if you are ever being harassed by a crow/raven it is highly likely their nest is nearby and they are just protecting their territory (or you were mean to them first). There is even a website named Crow Trax to track Crow Attacks due to them protecting their young. http://giscourses.net/crowtrax/crowtrax.html
Unfortunately, over 50 percent of crows die during their first year of life. Fully grown crows have very few predators with humans and hawks being the biggest threat to the birds. Young crows however, are susceptible to a large array of predators including owls, raccoons and other animals. Many young crows die from starvation or adverse weather conditions.
The average lifespan of a crow depends on how many predators are nearby. Experts disagree which may be based on locality. Some say average life of 7 to 8 years, others say average lifespan is 20 years. In captivity crows have been know to live over 50 years with one named Tata that lived to 59. [1]
For ravens the lifespan in the wild is 15 to 20 years and in captivity can be 70 to 80 years.
Similar to humans, crows and ravens are able to eat just about anything. Grains, meat, bugs, plants, nuts… even junk food. One of the easiest foods to carry with you is unsalted peanuts. These make great food for crows as they can be thrown, are easy to see from a distance, plus most other birds and animals will ignore them.
A crow knows friend from foe. Numerous studies have proven that crows recognize and memorize faces of humans. If the human has wronged the crow not only will the crow swoop and harass the person but will tell other crows to do likewise. For example, poking at a dead crow is considered desecration and very offensive. Trying to catch crows or throwing rocks at them will earn you enmity. Scientists have tried these test wearing masks and found even several years later if anyone wore that same mask on campus the crows would throw up alarms. This happened even if the masked person wore a hat and different clothes. Moreover it was discovered even crows that did not see the original offense would recognize and attack the offender which proves that crows could pass on the information in detail even to their offspring!
On the flipside, if you are kind to crows that is also remembered and passed around their crow buddies. I often carry with me shelled unsalted peanuts. I have noticed if I throw a handful of peanuts to a crow, then I drive a couple miles and see other crows I am always impressed how the new crows seem to automatically know that I’m a friend and have food available.
Next time you see a crow throw them a peanut and bid them regards.
Crows and ravens are known to steal and cache shiny objects such as pebbles, pieces of metal, and even golf balls. Especially juveniles are deeply curious about all new things. Some speculate that ravens retain an attraction to bright, round objects based on their similarity to bird eggs.
Crows can actually be taught to find coins and trade them for peanuts. This has been documented multiple times but so far the only time it was really successful was with teaching captive crows. Theoretically it should be possible with wild crows and exact plans have been outlined. There are actually two models of special vending machines made to entice crows to scavenge for coins, bring them to the vending machine and “purchase" peanuts.
Here’s an NPR article discussing the original invention/idea which was also in a TED Talks.
There is now a website for “The Crow Box” at: http://www.thecrowbox.com/ but I think the design described here is superior: http://www.dailymail.co.uk/sciencetech/article-2982961/
It has been discovered that some ravens are more trustworthy than others… and that ravens remember whom they can trust. A study was done where a raven was put in a large cage with plants and lots of places to hide/cache food. Another raven was allowed to watch. If the second raven stole the food, the first raven in future would not cache while they were watching. If the second raven did not steal the food, the first raven would continue to cache their food if they were around. [2]
I hate to say it, but it takes a kind of cunning to be a thief.
The brain-to-body weight ratios of corvid brains are among the largest in birds, equal to that of most great apes and cetaceans, and only slightly lower than a human. Specifically, their hyperpallium is large, for a bird. They display ability in problem-solving, as well as other cognitive processes such as imitation and insight.
Corvid intelligence is boosted by the long growing period of the young. By remaining with the parents, the young have more opportunities to learn necessary skills. Both of these birds are extremely intelligent (though ravens seem a bit smarter than crows) and are quite playful. Ravens have at least 7 different calls and can imitate the calls of other birds (geese, jays, crows). Corvids have been recorded to recall their food's hiding place up to nine months later. They also use stunt flying to attract mates (barrel-rolling, flying upside-down, and somersaults).
Corvid ingenuity is represented through their feeding skills, memorization abilities, use of tools, and group behaviour. Living in large social groups has long been connected with high cognitive ability. To live in a large group, a member must be able to recognize individuals and track the social position and foraging of other members over time. Members must also be able to distinguish between sex, age, reproductive status, and dominance, and to update this information constantly. It might be that social complexity corresponds to their high cognition.
The Eurasian magpie is the only non-mammal species known to be able to recognize itself in a mirror test. Magpies have been observed taking part in elaborate grieving rituals, which have been likened to human funerals, including laying grass wreaths. Marc Bekoff, at the University of Colorado, argues that it shows that they are capable of feeling complex emotions, including grief.
There are also specific examples of corvid cleverness. One carrion crow was documented to crack nuts by placing them on a crosswalk, letting the passing cars crack the shell, waiting for the light to turn red, and then safely retrieving the contents. A group of crows in England took turns lifting garbage bin lids while their companions collected food.
The ability to hide food requires highly accurate spatial memories. Corvids have been recorded to recall their food's hiding place up to nine months later. It is suggested that vertical landmarks (like trees) are used to remember locations. There has also been evidence that California scrub jays (also a corvid), which store perishable foods, not only remember where they stored their food, but for how long. This has been compared to episodic memory, previously thought unique to humans.
New Caledonian crows are notable for their highly developed tool fabrication. They make angling tools of twigs and leaves trimmed into hooks, then use the hooks to pull insect larvae from tree holes. Tools are engineered according to task and apparently also to learned preference. Recent studies revealed abilities to solve complicated problems, which suggests high level of innovation of a complex nature. Caledonian crows can use up to three tools in sequence to obtain food, which the University of Oxford’s Behavioural Ecology Research Group said is the first demonstration of spontaneous sequential tool use in a species other than humans. In another astonishing test set up by BBC Two, a crow called 007 completed an eight stage puzzle in two and a half minutes. It is one of the most complex tests of the animal mind ever devised. Other corvids that have been observed using tools include the American crow, blue jay and green jay. Diversity in tool design among corvids suggests cultural variation. Great apes are the only other animals known to use tools in such a fashion.
In captivity, ravens can learn to talk better than some parrots. They also mimic other noises, like car engines, toilets flushing, and animal and birdcalls. Ravens have been known to imitate wolves or foxes to attract them to carcasses that the raven isn't capable of breaking open.
If you trace back far enough, all creatures evolved from dinosaurs. Different dinosaurs come from different eras. Crows and corvids evolved from a more recent dinosaur era than mammals and humans did. The significance of this is that their brains are actually wired differently and one might think possibly superior to mammals. For would not dinosaur brains evolve and thus if corvids are from the branch that succeeded our mammalian branch in some ways they have a potential intellectual advantage?
This shows that birds evolved from dinosaurs of 200 million years ago, whereas humans evolved from the evolutionary branch that departed 320 million years ago.
A crow knows more than you think. Their intelligence appears to be equal or even greater than that of the great apes. For example, nutcrackers (also in the corvid family) have the capacity to recall thousands of locations where they have cached food items — a capacity that exceeds that of humans. [3]
When compared to dogs and cats in an experiment testing the ability to seek out food according to three-dimensional clues, corvids out-performed the mammals. A meta-analysis testing how often birds invented new ways to acquire food in the wild found corvids to be the most innovative birds. A 2004 review suggests that their cognitive abilities are on par with those of great apes. Despite structural differences, the brains of corvids and great apes both evolved the ability to make geometrical measurements.
Corvids are easily the smartest of the birds, although possibly not the most ethical. Members of the corvid family have been known to watch other birds, remember where they hide their food, then return once the owner leaves. Corvids also move their food around between hiding places to avoid thievery, but only if either they have previously been thieves themselves or they have caught a thief stealing from one of their caches in the past. Studies to assess similar cognitive abilities in apes have been inconclusive.
It is argued that ravens are one of only four known animals (the others being bees, ants, and humans) who have demonstrated “displacement", the capacity to communicate about objects or events that are distant in space or time from the communication. Young, unmated ravens roost together at night, but usually forage alone during the day. When one discovers a large carcass guarded by a pair of adult ravens, the unmated raven will return to the roost and communicate the find. The following day, a flock of unmated ravens will fly to the carcass and chase off the adults. Linguist Derek Bickerton, argues that the advent of linguistic displacement was perhaps the most important event in the evolution of human language, and that ravens are the only other vertebrate to share this with humans. [4]
Their aptitudes for solving problems individually and learning from each other reflect a flexible capacity for intelligent insight unusual among all other animals (except humans).
This amazing video shows the multiple intricate steps one crow used (including opening a gate) so it could steal dog food. https://youtu.be/3_pYhbxaeos
Over the last 100 years humans have caused extinction of over 500 species [5] but due to their intelligence and eating flexibility, crows are flourishing as a species.
In a recent experiment with New Caledonian crows, the birds demonstrated that they have a better understanding of water displacement than humans as old as 5 to 7 years. [6]
Scarecrows have historically been used as a scare tactic to keep birds out of fields. However, due to crow intellect they merely use scarecrows as perches which has actually allowed them to expanded their territories and strengthened their numbers.
In Japan crows were causing blackouts due to their nests on power lines and later their use of fiber optic cables for nesting material. Japan electric companies fought back with “Crow Patrols” that would destroy nests. The crows devised a brilliant counter-plan of building dummy nests until there were more “fake” nests than real ones. This both wasted the time of the Crow Patrol and made it so when they did destroy a real nest there were plenty of extra nests available nearby. Eventually Japan gave up and started building nests in alternate areas as a peace offering and bribe to lure crows elsewhere since outright war on them failed. [7]
Personally I do not know of a single crow that has eaten a Tide pod [8]. Nor do I know a single raven that has snorted a condom [9]. Thus from those facts alone I think it can be easily argued all crows are smarter than the thousands of humans who have partaken in those activities.
Not only do crows have good memories, but they are logical and understand advanced mathematics. We humans often take flying skills of birds for granted. Flying requires constantly calculating the distance between one point and another which in algebra is a function called “mag( )”. [10]
How many humans do you know that understand and can calculate mag()? How many humans can calculate mag() without pencil and paper?
In summary, crows have better tool use and understanding of displacement than youth under 7 years old. They have turned farmer’s best plans into their sky rises to expand their territory. They outsmarted electric companies in Japan. They are not retarded and inflicting self-harm like the current generation of teen agers. And last but not least, say this last one out loud with me…
A crow knows mag, oh yes!
2) Science Blog: How Smart are Ravens
3) Crows may be as intelligent as apes, scientists say
5) Humans: Cause Of Extinction Of Nearly 500 Species Since 1900
6) Using the Aesop’s Fable Paradigm to Investigate Causal Understanding of Water Displacement by New Caledonian Crows
Sarah A. Jelbert , Alex H. Taylor, Lucy G. Cheke, Nicola S. Clayton, Russell D. Gray
7) 5 Diabolical Animals That Out-Witted Humans
(do a search on "Japan crows” for tons of other stories)
8) Tide Pods 2018 statistics and Washington Post
In 2017, there were 12,299 calls to U.S. poison control centers due to exposure to laundry pods, according to AAPCC's latest data. That number is actually down by about 14 percent since 2015, when there were over 14,000 calls.
The challenge has been around for more than a decade with YouTube videos dating back to 2007. One channel devoted to the challenge created in 2013 has more than 100 videos of people participating.
Description: Calculates the magnitude (or length) of a vector. A vector is a direction in space commonly used in computer graphics and linear algebra. Because it has no "start" position, the magnitude of a vector can be thought of as the distance from the coordinate 0,0 to its x,y value. Therefore, mag() is a shortcut for writing dist(0, 0, x, y).
Crows Are Smart, But Are They Smart Enough to Fall in Love?
Highly scientifically detailed article on why corvid brains would be better for neuroscience testing than apes.
We Knew Ravens Are Smart. But Not This Smart
Ravens Hold Grudges Against Cheaters
6 Terrifying Ways Crows Are Way Smarter Than You Think
Good discussion on comparisons of rooks with crows and raven
Funny summary of crow coolness
Causal understanding of water displacement by a crow
Are crows the ultimate problem solvers?
Great video on differences between Crows and Ravens
10 Odd Facts about Crows and Ravens
The entire Raven Diaries series and Rick Boufford videos.
Stealing, Spying and Bluffing: The Raven
Smart Crow uses cars to crack nuts in Akita, Japan near Senshu Park
What Is the Difference Between a Raven and a Crow