Crows are highly intelligent birds that exhibit complex behaviors not seen in many other animals. One remarkable ability that has intrigued scientists and birders alike is whether crows can understand human language. Studies conducted over the past few decades provide compelling evidence that crows are capable of interpreting various elements of human communication.
What do we know about crow intelligence?
Crows belong to the corvid family, which also includes ravens, jays, and magpies. Corvids have the largest brain relative to body size of any bird species. Their brains have as many neurons as some small monkeys. This allows corvids to perform complex cognitive tasks and exhibit behaviors associated with general intelligence.
Some examples of advanced intellectual abilities in crows include:
- Using and modifying tools to acquire food
- Spatial memory and navigation skills
- Social learning and teaching offspring/peers
- Ability to solve problems and adapt to new situations
- Capacity for causal reasoning to understand relationships between events
These complex behaviors require strong learning capacities and mental flexibility. Given their intelligence, it is plausible that crows may also have the ability to comprehend elements of human communication.
Evidence that crows understand meaning of human gestures
In one experiment conducted at the University of Washington, researchers trained wild American crows to bring them various items in exchange for food rewards. The crows were taught to exchange coins or other small objects to receive a food treat.
During testing, a researcher would gesture towards the crow – either holding out an open hand, waving, or doing a “come here” motion. The crows quickly learned that when a human extended an open hand, it meant they wanted the crow to give back the object it was holding. Other gestures like waving or beckoning signaled that the crows could approach and receive a reward.
| Human Gesture | Crow Interpretation |
|---|---|
| Open palm held out | Give back object in your beak |
| Waving hand | Come get your food reward |
| “Come here” motion | Approach the human |
The crows reliably exchanged objects when a human extended their hand and came nearer when waved at or beckoned to. This indicates they learned to associate specific gestures with their meaning. Since the crows had no previous experience with these gestures, it suggests an ability to interpret human body language.
Crows can interpret human facial expressions
In an experiment by Dr. Andreas Nieder at the University of Tübingen, crows were shown images of human faces on screens. The faces displayed different expressions – threatening (angry), caring (happy), or neutral. Food treats were dispensed from openings at the bottom of the screens.
When presented with angry faces, the crows avoided the openings where food was dispensed, suggesting they interpreted the angry expressions as threatening. They readily approached the openings for happy expressions, which they associated with a caring attitude. This shows crows can distinguish human facial cues.
| Facial Expression | Crow Response |
|---|---|
| Angry face | Avoided food reward |
| Happy face | Approached food reward |
| Neutral face | No strong reaction |
Crows understand meaning behind human vocalizations
Studies at the University of Washington provide evidence that crows can differentiate between subtle differences in human vocalizations to decipher meaning.
In one experiment, researchers captured wild crows and handled them while making pleasant vocal sounds like “woo woo” or unpleasant sounds like “uwgh uwgh”. The crows were then released.
When the same researchers walked around wearing masks, the crows scolded and dive-bombed those who had previously handled them while making unpleasant sounds. They avoided the researchers who had made pleasant sounds.
This shows crows can associate specific human vocalizations with whether a person intends to threaten/harm or be friendly. They can use this to identify individuals who pose a potential danger even when in disguise.
| Vocalization | Crow Interpretation |
|---|---|
| Pleasant sounds | Friendly human |
| Unpleasant sounds | Threatening human |
Crows recognize individual human faces
Researchers in Seattle performed an experiment where they captured crows while wearing particular masks. The crows were then released. Later, when the scientists wore the same masks again, the crows scolded them loudly – recognizing them as the individuals who had captured them previously.
When the scientists wore new masks the crows had not seen before, they did not act aggressively. This demonstrates crows can differentiate between individual human faces and remember them to identify specific people that posed a threat in the past.
| Mask | Crow Response |
|---|---|
| Familiar mask worn by captor | Aggressive scolding |
| Novel mask not seen before | No aggression |
Researchers believe crows may use facial recognition to identify kind or threatening people in their environment. Their ability to memorize human faces implies an understanding that different individuals have distinct identities.
Can crows comprehend human words and symbols?
The most direct test of whether crows understand human language would involve training them to associate written or spoken words with meanings. Unfortunately, little controlled research has been done in this area.
However, some pioneering studies suggest crows can learn to comprehend a few basic human words and symbols.
Dr. John Marzluff at the University of Washington trained captive American crows to recognize three human faces associated with actions like “threatening”, “nice”, or “ignore”. The researchers correspondingly did threatening, pleasant, or neutral behaviors when interacting with the crows.
When shown face cards with the images labeled as “thief”, “friend”, or “foe”, the crows reacted appropriately by scolding the “thief” face card and avoiding it. This demonstrates crows could associate human words with the concepts they represent.
In Germany, a crow named Kitty learned to recognize and respond to nearly 30 German words spoken by her owners. She carried out actions like “fetch” or “turn” when asked to in German, showing some comprehension of the verb meanings. However, controlled experiments are needed to validate Kitty’s abilities.
| Label | Crow Reaction |
|---|---|
| “Thief” | Scolding |
| “Friend” | Approach |
| “Foe” | Avoidance |
While intriguing, the current evidence for comprehension of human words by crows is limited. More rigorous research is required to determine if crows can interpret the meaning of human language, rather than just responding to visual or auditory cues.
Findings from brain imaging studies
Neuroscience research using brain scanning offers some clues about language comprehension in crows.
Dr. Andreas Nieder at the University of Tübingen found that crows’ brain activity changes distinctly when they hear human voices versus recordings of other crows. A specific region of the auditory cortex lights up more strongly in response to human vocalizations.
This same region shows selective activation when humans process human speech compared to other sounds. The similarities suggest crows may have a basic neurological capacity to recognize human vocal language.
However, Nieder emphasizes that the ability to distinguish human voices does not necessarily mean crows can understand language itself. More research is needed to decode if they comprehend the semantic meaning of words.
Concerns about flaws in experimental design
While several studies imply crows can interpret human gestures, facial expressions, and vocalizations, some experts argue that flaws in experimental design make the results inconclusive.
Critics point out that most studies involve conditioning crows to make an association between a stimulus and reward or punishment. For instance, crows learned to associate an angry face with a punishment of not getting food.
But this does not necessarily demonstrate that crows grasp the higher-level concept of a human emotion. They may simply associate facial configurations and sounds with outcomes, without an understanding of meaning.
Better controls are needed – such as testing if crows can match emotional faces and sounds with corresponding scenarios. Advocates argue we should be cautious about projecting human-like language comprehension onto crows based on current evidence.
Do crows have their own languages?
Crows engage in sophisticated vocal communication with each other. They have a repertoire of over 250 distinctive call types used in various social contexts. For instance, crows make different alarm calls depending on whether a predator is in the sky or on the ground.
Researchers have identified some crow calls that communicate concepts like “threat detected”, “food here”, or “gather around”. Some even convey more complex notions like “potential danger, let’s move closer together”.
Crows also appear to have regional dialects, with slightly different vocalizations between geographic areas. This suggests cultural evolution of calls within crow populations.
While crow communication is highly advanced compared to other birds, researchers stop short of calling it a true language. Linguists argue that crows lack key elements of human language like syntax, grammar, displacements (ability to communicate about abstract concepts not in the present), and productivity (limitless expression).
Nonetheless, the communicative complexity of crows implies an ability to comprehend meaning, which could enable understanding of human language.
| Crow Call Type | Inferred Meaning |
|---|---|
| Short, sharp calls | Predator spotted |
| Rhythmic, guttural sounds | Food source detected |
| Soft, low coos | Nesting instructions for mate |
Conclusion
In summary, numerous studies demonstrate that crows can interpret human gestures, facial expressions, and vocalizations. Their ability to extract meaning from human communication signals is notable. However, the jury is still out on whether crows comprehend human language itself at a deeper semantic level.
Crows clearly possess strong abstract reasoning abilities. With their large brains, capacity for social learning, and grasp of contextual information, crows likely have the raw intelligence to potentially process basic language. But more rigorous research isolating specific words and grammar features is needed before concluding crows understand human language.
The cognitive capacities of crows provide tantalizing clues that birds may one day surprise us with human-like language comprehension. Continued two-way communication experiments with crows promise to offer deeper insights into the evolution of intelligence and cognition across species, including our own.