Do birds have intelligence?
The answer is undoubtedly yes. In fact we might say that everything has a certain innate intelligence – it’s ability to deal with variability in the world it experiences.
But this intelligence is itself highly variable in form and function. Somewhere, from rigidly hard-wired, innate actions arise the ever increasing degrees of choice, flexibility, creativity and consciousness that we call intelligence. Having accepted that intelligence is something measured on a continuum, we must accept that birds have some intelligence.
The next questions then are how much intelligence do birds have and how well does bird intelligence compare with the intelligence of other animals?
Answering these questions is difficult, as I noted in the general introduction to thinking about animal intelligence, scientists are still arguing about what intelligence really is, and how to measure it in people. Measuring intelligence in birds, or any other animal is considerably more difficult.
Secondly I need to reiterate that birds is a category of over 10,000 species. As with all classes of animals, some species are more intelligent than others. Nobody would think a mouse or a sloth were as intelligent as a human or a dolphin simply because they are all mammals; the same applies to birds. Further more as with humans and other mammals, intelligence is a variable trait even within a species.
Having said all that let us begin to look at what science can tell us about bird intelligence today in the year 2020, remembering that the future will present new knowledge and new wonders as it unfolds.
A New Beginning
Since the 1990s bird intelligence has become somewhat of a hot topic and more and more research is done into answering the questions about bird intelligence every year.
Bird intelligence was launched into the limelight by Irene Pepperberg and Alex (although many scientists denigrated her work when it was first published). Irene Pepperberg is an American scientist who initially studied chemistry, gaining her PhD in chemical physics before she found her true calling and became fascinated with language learning in birds.
Alex was an African Grey Parrot (Psittacus erithacus), he was hatched in May 1976 and sadly died at the young age (for his species) of 31 on the 6th September 2007. After his death Neil deGrasse Tyson held did a special about him on his show Nova Science.
Pepperburg taught Alex words as names and concept differentiation and in the last decade of his life he became an international star, frequenting many TV shows. His obvious intelligence and wonderful personality oversaw a surge in scientists studying bird brains.
Pepperberg never claimed that Alex used language the way we do however some of the things he did were truly amazing. He once called an apple, a fruit he was unfamiliar with at this point and hadn’t been taught, a ‘banary’ (to rhyme with canary). It has been suggested that he invented this word from a mixture of ‘banana’ and ‘cherry’ two fruits he already knew well.
In 1999 Pepperberg stated that Alex had learned the following;
- Could identify and name 50 different objects,
- Could recognize and distinguish the number of objects up to six,
- Could distinguish and name seven different colours,
- Could recognize and name five different shapes,
- Could distinguish correctly the terms bigger, smaller, same and different.
He had learned to show that he could do this in English, how the minds of such birds work in their natural environment we still are a long way from understanding.
It is reported that once, when shown his own image in a mirror, he said “What colour?”. This would make him the only non-human animal to ever use human language to ask a question. He was told gray, and after 6 repetitions he had learned the name gray as a colour.
Modern Bird Intelligence Research
Assessing and measuring any kind of intelligence is difficult.
Some scientists suggest that evidence of innovative behaviour and inquisitiveness can be seen as indicators of bird intelligence. Different birds seem to observe and respond to the world around them in different ways. In her wonderful and highly informative book “The Genius of Birds’ Jennifer Ackerman reports two different stories of her time spent with the scientist Louis Lefebvre, the first scientist to device an intelligence scale for birds.
In the first story Lefebvre and Ackerman are in a field observing some birds. Lefebvre scatters some seeds in the grass and retreats to observe. Very quickly the seed is discovered and announced by a group of Caribbean Grackles (Quiscalus lugubris) that were in some nearby trees, they are followed closely by some doves and then some Barbados Bullfinches (Loxigilla barbadensis) that come to share the bonanza. All of these birds were further away from the offered seeds than a small group of Black-faced Grassquits (Tiaris bicolor).
The grassquits are seed eaters and cannot have possibly been unaware of the situation, yet they ignored the seed, presented in such an unusual way completely, and continued their traditional foraging.
Some birds are more inquisitive and will to try new things more readily than others, just like people. This can be true within a species as well as between species. Scientists believe there are advantages to being curious and courageous, but also dangers, sometimes it is better to stay with what you know and sometimes the only way to survive is to try something new. Species that carry a mix of characteristics improve their chances that some representatives of their species will survive whatever the world throws at them.
In the second story Lefebvre describes some research he published in 2005 resulting from his indexing 2,300 instances of published reports of birds doing something novel, something out of the normal that they had not been seen doing before, and then correlating the relationship between a bird family’s number of recorded instances of novel behaviour and their brain to body weight ratio.
His evidence suggests that there was a definite correlation. Birds with bigger brains are more likely to do new inventive things.
The leaders in the novel activity table were, unsurprisingly, the corvids (crows, ravens, magpies and jays etc,). Up at the top with them were the parrots, followed by grackles, raptors, woodpeckers, hornbills, gulls and herons.
Scientists that study bird intelligence take two basic approaches.
The first involves anatomical studies of brains, measuring, counting and testing the actual physical source for intelligence. The second involves studying birds (and other animals) as they do things, observing and comparing their natural behaviours and setting them problems in controlled situations.
The Physical “Bird Brain”
How do birds’ brains stack up in comparison with mammals’ brains? Does neurology give us any reason to suppose birds should be intelligent?
Up until about 30 years ago most scientist believed that intelligence required big brains. Birds were observed to be small animals with small brains and so they were, for the most part considered to be very machine like, possessing no conscious thought or ability to learn. However that idea has now been proven entirely false.
The next step was the idea that the ratio of brain weight compared with whole body weight, was a more important indicator of intelligence. Science now knows that animal species with large brains in proportion to their whole body weight do tend to be the more intelligent ones and that they also tend to live longer as individuals in their natural environment.
However this is a general trend that it is to some extent limited as an indication of intelligence, nevertheless it is a better method for estimation than simple brain weight.
In mammals Tree Shrews have a higher ratio of brain to body mass, at around 2.6, than humans who have a ratio of around 1.86. However nobody is suggesting that Tree Shrews are more intelligent than humans. For comparison, an African Grey parrot like Alex has a ratio of 1.72, a Bottle Nosed Dolphin a ratio of 1.25 and a Chimpanzee a ratio of 0.88.
Looking Deeper
Brain weight to body weight ratio was a good step forward in looking at the physical characteristics as indicators of intelligence, but it is just the beginning. A more accurate predictor of bird intelligence is the ratio of that part of the brain called ‘cortex’ in mammals and called the ‘nidopallium’ in birds to the rest of the brain. (Because their brains are so differently designed to ours they have a separate nomenclature). This is the part of the brain responsible for the behaviours we generally consider to be intelligent.
A fourth way to measure things is to count the actual neurons. A good job for a rainy afternoon. The number of neurons in bird’s brain varies greatly between species. Small songbirds like the European Goldcrest (Regulus regulus), with a total weight of 5.5 grams, have about 164,000,000 neurons in their very small brains.
However, to put this into perspective, a house mouse, weighing ten times as much at around 55g has only 71,000,000 neurons, less than half as many. Yet many people consider their pet mice to be relatively clever little creatures.
Larger birds, particularly the corvids and parrots, have much higher neuron counts. A Raven (Corvus corax) has about 2.2 billion neurons, far more than the mouse or the Goldcrest and more than a raccoon, another animal known for being pretty clever.
The bird with the highest neuron count (of those we have measured) is the Blue and Yellow Macaw (Ara ararauna) with just under 3.2 billion neurons. For comparison a dog has around 2.6 billion.
As with all these categories of measurement, absolute numbers are not the whole story. Although humans range far above any of these animals with an impressive 86 billion neurons, this is again put to shame by elephants which boast a massive 257 billion neurons – over three times as many.
So a high neuron count might well be a good indicator of intelligence but we cannot simple line animals up by their neuron count and label the highest the smartest and the lowest the dumbest.
Neurologically another important factor is the density of neurons, densely packed neurons can form connections more easily and support a greater number of connections all of which helps when being intelligent. Looking at things this way we see that various birds pack their neurons much more densely than mammals, including humans. However, to some extent neuron density increases with decrease in body size, so on it’s own it is not a good predictor of intelligence.
Bird brains do not look like mammal brains, they are designed to be small. Our closest common ancestor lived about 300,000,000 years ago. In human’s the forebrain, or cortex makes up about 75% of the brain and in bird brains the ratio is similar.
Other Bird Brain Measurements
Two other indicators of intelligence are:
- developmental time from birth/hatching to reproduction, and
- growth of the brain after birth/hatching.
Brain growth after birth hatching is a reasonably good indicator of intelligence, the weight of a human baby’s brain is about 25% that of an adult human’s. Our brains grow massively during our first few years of life. Similarly the birds we think of as being the most intelligent show considerable brain growth after hatching, while those we think of as less intelligent have brains that develop very little after hatching.
Precocial birds (those able to leave the nest and forage almost immediately after hatching) have larger brains on hatching, but their brains develop very little form thereon in. Altricial birds, (those that are hatched still relatively helpless and need to be fed by parents for a length of time before they can even walk) have smaller brains on hatching, but their brains grow much more while they are in the nest resulting in them being proportionally larger-brained as they approach maturity.
The time taken between hatching/birth and reaching reproductive maturity is another good indicator of intelligence. Animals that have long juvenile times are usually the most intelligent. Whales, dolphins, elephants, apes and particularly humans all have big brains and spend years growing up.
This growing up is a time of intense learning for all these species, and it is learning, rather than simply following hard-wired programming that we consider an indicator of intelligence.
Both corvids, and parrots also have relatively long juvenile life periods. Ravens (C. corax) take at least three years to reach sexual maturity and African Grey Parrots do not breed until they are four to five years old. Further to this both species can live to be forty years old, at least in captivity long life spans are typically associated with larger brains.
Larger brained birds it seems survive better and live longer than their smaller-brained cousins.
So how do birds do overall?
The answer is they do very well.
Just looking at brain to body ratio we see that some birds, like parrots and corvids do quite well, they have weight ratios around the human mark of 2%. When we look at the amount of cortex in birds and mammals, the birds do even better – with the smartest species having equivalent percentages to the smartest primates.
To sum up the scientific evidence, modern neurological studies tell us that we should expect some birds to be smart.
Their brains may be small, but they are densely packed and they contain comparable numbers of neurons and high percentages of the sort of brain structures responsible for intelligent behaviour.
They continue to develop after birth, in some species and they operate more as a result of learning, than from reprogrammed habits. It seems that bird brains are good brains.
Daniel Sol and his co-workers have shown that survival in both regular and novel environments is higher for birds with larger brains, not only at the species level but also even more strongly at the level of family. They have also shown that this survival is a result innovative behaviour arising from those larger brains. They report:
“Thus, assuming that innovation rate is an accurate measure of cognitive ability, large brains appear primarily to help birds respond to novel conditions by enhancing their cognitive skills rather than by other mechanisms.”
In other words these birds owe their success to their intelligence, and their intelligence to their relatively larger brains.
Now it’s time for us to look at behavioural observations of bird intelligence.
Learning In Birds
The internet is awash with videos of corvids solving problems and parrots doing cute things that demonstrate their immense ability to learn. There is no doubt in our modern minds that birds have the sort of intelligence that allows for learning.
However many of these Internet stars are taught and live in highly unnatural environments. Studies of humans have shown that early developmental environment and cerebral stimulation facilitate the development of intelligence. Birds that are stimulated by an anthropogenic environment and taught by clever, patient human instructors may not be honest examples of learning in birds.
The real question is do birds demonstrate learning in the wild?
Scientists test behavioural intelligence in animals by looking at a number of different behaviours including play, tool usage, social behaviour, learned vs innate behaviour, memory, response to novel situations, mathematical ability, problem solving using novel behaviour, inhibitory control, self awareness, and awareness of other minds.
Only a few species of birds have been tested for any, never mind all, of these characteristics. However studies have shown that the smartest birds, parrots and corvids do as well as the brightest non-human primates (apes, baboons and monkeys). Birds have the brains and they know how to use them.
Social Interactions
Most of the bird species that have been shown to display one or more of the categories that imply intelligence are social, meaning they live, and interact within a group. Group living implies recognition of individuals and the formation of emotional bonds outside of a mating partner. Parrots and corvids, especially Ravens (C. corax) are renowned for bonding well with humans that raise them.
Ravens demonstrate a very high level of social flexibility. Ravens form friendships, hold grudges, cooperate well, they remember and value fair play in reciprocal exchanges. They can also compete well.
They maintain long-term, monogamous relationships in the midst of large and complex social gatherings.
Birds often have excellent memories and corvids are well known to recognize and remember friends and enemies, within their own species, and occasionally in domestic situations, with other species, over long periods of time (years, in some cases even decades).
Birds Recognizing Enemies
Research in the USA by John Marzluff has shown that American crows (Corvus brachyrhynchos) recognize people who have trapped them (when they are wearing a mask) and will harass anybody wearing the same mask. Not only that, but their young and their neighbours learn to recognize the intruders from them.
In one instance crows mobbed a researcher more than a year after the initial incident!
In another experiment conducted by Kaeli N.Swift on the same species, the crows reacted to masked people holding a dead crow nearby a feeding site more violently than to a person holding a dead pigeon. Their scolding calls signify, and warn others of, danger.
These crows continued to recognize and scold the masked people for a further six weeks (the full length of the experiment). They scolded masked visitors on later visits to the feeding sites even when the masked individuals were empty handed. They did not scold masked (different masks) individuals who had only ever been seen empty handed.
Meanwhile, in Korea other ornithologists discovered, by accident, that Common Magpies (Pica pica) can recognize and remember human faces and that changing clothes and hats does not interfere with the magpies’ recognition. Individuals who had climbed to nests to plant cameras were remembered and harassed on later occasions. The same birds did not harass people who hand not invaded their nest space.
Birds Recognizing Their Friends
On the plus side, crows are also known to reward kindness. They create relationships within their groups based on reciprocal acts, develop trust and show offense if that trust is broken.
They have a sense of inequity and react in a number of ways to show their annoyance when they think they are being treated unfairly. Sometimes by refusing to participate in an experiment any further.
The fact that American crows sometimes bring gifts to humans who have fed them became well known after the BBC produced an article of the gifts given to eight-year-old Gabi Mann of Seattle. Since then, a number of other people have come forward with examples of gifts left them by the same species of crow.
Grieving Their Dead
Another example of social interaction is the way some species of birds react to the discovery of a dead conspecific (member of the same species).
Western Scrub Jays (Aphelocoma californica) are reasonably well known for holding ‘funerals’ when they find a dead on the ground somewhere. Scientists call these gathering cacophonous aggregations.
Scientific study casts doubt on the idea that these are funerals in the sense of displaying sorrow over the death of an individual. These aggregations are usually started by a single bird after finding a dead individual, the finder flies up into a nearby tree and emits loud alarm calls that are recognized by other WS Jays. Any WS Jays that hear the calling bird fly to the area and begin calling themselves, thus attracting even more jays. The end result can be up to 30 birds making a lot of noise around a dead individual.
Scientists are unsure exactly what the reason behind these gatherings is. Western Scrub Jays are highly intelligent birds. Studies have shown that they don’t react in the same way to other species deaths, or to dead birds posed as live ones.
It seems obvious that they recognize the dead bird as one of their own kind, even if it isn’t an individual they know. Also they understand that the bird is dead. It has been suggested that they are responding to, and alerting conspecifics to, a potential danger. However it is still difficult to see what evolutionary benefit the jays get from this behaviour.
Even more interesting is the question of bird funerals in Magpies (Pica pica), crows and ravens.
In these situations birds are seen to aggregate around a dead individual for varying amounts of time, calling, nudging or pecking the body and even laying items such as grass or sticks across it. In 2005 Marc Bekoff, a respected researcher into the world of animal minds and hearts, published a report of watching four magpies perform such a ceremony.
This included birds departing and returning with collected dead grass to lay near or on the dead bird. He subsequently received numerous communications from other people reporting having seen the same thing, but not just magpies
They also reported seeing these ‘funerals’ being performed by crows and ravens.
European farmers have long known that corvids have a strong dislike of seeing their own species dead. This has resulted in the grizzly habit of the farmers of killing a few crows or rooks and displaying their dead bodies prominently around fields where they might like to forage.
We cannot project human emotions onto animals whose evolution has been so different to our own. However neither should we use this difference as an excuse to deny emotions, and emotionally driven behaviour in other species. The reactions of tribal humans to dead humans is markedly different depending on whether the dead individual is either of the ‘ingroup’ or the ‘outgroup’.
They have also been quite variable across the planet. Perhaps the only honest approach is to admit just how ignorant we really are of the extent and depth of inner lives in animals other than ourselves.
Mathematical Ability in Birds
The ability to count, meaning the ability to look at two groups of similar things and know that eight is more than six (regardless of arrangement or previous experience of the particular objects) may seem simple to us, but it is beyond the ability of most animals.
In the 1990s the scientific community was excited when it was proven that Rhesus Monkeys could count, at least up to nine.
However when other scientists showed in 2011 that common city pigeons (Columba livia domestica) could do the same math as well as the monkeys, the world was astonished. Pigeons, despite their mathematics and awesome homing abilities do not do so well in other bird intelligence tests. However we now no that parrots can count to six and that crows and ravens can count to eight.
Further to this, some scientists at the university of University of Tübingen in Germany demonstrated in 2015 that crows have special neurons in their brains that recognize numbers. One set of neurons fires on seeing three, a different set fires on seeing four, etc.. “When a crow looks at three dots, grains or hunters, single neurons recognize the groups’ ‘threeness’ “, says Helen Ditz. “This discovery shows that the ability to deal with abstract numerical concepts can be traced back to individual nerve cells in corvids.” This is very similar to how numerical recognition works in primates.
No tests have been done on higher numbers yet, so these figures should be thought of as ‘at least’.
Tool Usage
Tool use, as defined by R. St. Amant, and T. E. Horton, in 2008, has been observed in 135 species of birds. However this includes activities such as anting, when birds deliberately put ants, millipedes and other objects on their feathers as a method of parasite control.
Notably the above definition of tool usage does not include nest building, something most, but not all, birds indulge in. Some people think that nest building (see bird nests), because it involves the deliberate acquisition and usage of external materials for a desired end should be considered a tool using activity.
One study by Yvonne Christina Roelofs reveled that among raptors, nest building species such as eagles have larger brains (proportionately) than non-nest builders like falcons.
Scientists know that good nest building does not indicate a high level of intelligence in birds. Pigeons, now well known for their mathematical abilities and the fact that they can learn to distinguish between different styles of art, build some of the flimsiest nest of all birds. In fact repetitive actions that result in complex nests have been shown to be produced by innate behaviours.
Learning To Build
Few species of birds have to learn very much in order to be able to build a nest. It is difficult, when observing a bird build a nest to distinguish between innate, inherited behaviours and learned behaviours.
Learning by experience has been documented in Southern Masked Weaverbirds (Ploceus velatus). In some species, such as Zebra Finches (Taeniopygia guttata), competence is built up through practice and by observing older birds.
Another notable examples of learning in nest building are the bower construction of certain bowerbirds in which it has be observed that males need to learn, from observation of the work of older birds, how to perfect their own bowers/nests in order to be successful. Male bowerbirds not only collect, modify and precisely place items to build their bowers, in some cases they use chewed bark to paint their creations.
Other simpler forms of tool use include drumming, dropping things, (bones or tortoises to break them open), rocks and other materials to deter intruders, and the use of stones to crack open animal shells and nuts. This can involve either holding the food object and hammering it against a rock, or holding a stone and hammering it against the food item.
More impressive examples of tool usage include the use of various items, sticks, moulted feathers etc to assist in grooming behaviours (parrots and corvids). The use of twigs and grass stems to access insects otherwise beyond reach (numerous species). Dunking food items in water to make them easier to swallow and using absorbent items such moss to bring water to young in the nest.
In this later case the moss is wrung out by the adult to deliver the water to the young.
Bait Fishing
One really fascinating example of tool usage is the use of baits to attract fish by corvids and several species of herons. These baits can be bits of plastic, grass, insects and bread.
This is interesting because when the bait used is itself an edible item, usually an insect or a piece of bread, using it for bait means the bird has to chose not to eat something both edible and nutritious – in the hope of achieving a greater reward later. Night herons (Nycticorax nycticorax) have been observed not only using bread to catch fish, but removing the bread from the water again when a fish too large to eat shows an interest in it.
A much more cognitively complex act than simply dropping something, as it involves making an act of will to resist an innate drive.
Another example of birds using bait is the American Burrowing Owl (Athene cunicularia). These delightful birds will collect animal faeces and place them near the entrance to their burrows (usually only in spring). This dung is the food of dung beetles, which in turn are the food for the owls.
Owls with dung outside their burrows eat ten times as many dung beetles as those without.
Scientists are currently doubtful that the owls have actually thought the process out as the time gap between collecting the dung and getting to eat the beetles is relatively long. They think it is more likely that collecting the dung evolved as part of a general collecting program and evolution selected for those that collected dung as the extra food it brought in increased their chances of survival and successful reproduction.
Sequential Tool Use
Tool usage in controlled laboratory environments is well documented. Scientists have also shown that some corvids are capable of what is called sequential tool usage, i.e. using one tool to access another tool that can then be used to access food.
The most famous example is that of a New Caledonian Crow (Corvus moneduloides) Called 007 solving an eight step problems of using tools to acquire another tool to be able to eventually access the reward as seen on the BBC.
Tool Construction
While tool usage, if we include nest building, is quite common among birds tool construction is a much rarer and cognitively impressive task. As far as I know only New Caledonian Crows (C. moneduloides) and Woodpecker Finshes (Camarhynchus pallidus) have been observed making tools in the wild. Constructing your own tools, deliberately, is an extra step up the bird intelligence ladder.
New Caledonian Crows, among the smartest of bird brains, have now been well documented as tool makers in the wild. They learn from older birds (often taking years to perfect their technique), have regional variation in tool shape and are known to value their tools. If a tool is dropped it will be retrieved from the ground.
It takes time and energy, as well as skill, to make a good tool. For the birds that make them these tools are valuable.
Tools that have been made are kept and stored in accessible places such as hollows in trees for later use.
Tool Usage For Play
Crows are known to use a variety of objects for play, a number of cases have been made quite famous as a result of becoming viral videos.
One famous example is of a crow using a jar cap to snowboard down a snow-covered roof. In the video the crow is seen to bring the jar cap back up to the peak of the roof several times to repeat its slide down. There is no obvious explanation here except play and fun, activities of leisure that were once considered to be solely human prerogatives.
In the wild corvids have frequently been observed playing with pieces of stone or wood. In some cases these are practice caching activities but in other cases they seem to be simply about manipulating an object out of interest or curiosity.
In his delightful book “Mind of the Raven” Bernd Heinrich often mentions watching Ravens play together. He also describes how young ravens are intensely curious about anything new that they see. He explains how this fascination with the new and unusual becomes completely reversed as the ravens grow in adulthood and become shy birds that are frightened of anything unknown. Both aspects of development can be seen as stable ecological practices.
Curiosity helps young birds to learn, while timidity keeps older birds alive.
Inhibitory Control
Inhibitory control tests whether and animal has enough conscious control of its own innate drives to override them and make a conscious choice to do something in a better way.
One way scientists test this is with food items in a transparent tube called ‘the cylinder test’. An animal, after learning that food can be obtained from the open ends of a non-transparent tube is presented with food in a transparent cylinder. The food can now only be obtained by going to the open end of the tube.
Most animals instinctively reach directly for the visible food because they can see it, ending up frustrated when they can’t reach it. This test demonstrates the ability to abstract learning from one situation to another and to use the learning to make a conscious choice of action. Ravens, crows and jackdaws have all passed this test, with the ravens doing best and scoring 100%.
Only chimpanzees and bonobos have previously done as well as the ravens, indicating that ravens are among the most intelligent animals in the world.
Self Awareness
Self awareness tests an animal’s ability to look in a mirror and recognize itself.
The numerous stories of European Robins (Erithracus rubecula) attacking their own image in car wing mirrors shows that these birds see mirror images as others, as competitors to be repelled, not as themselves.
Very few animals have ever passed this test. In 2008 some scientists discovered that the common European Magpie was able to recognize itself. They painted colour patches on the birds without them knowing this, then let them see themselves in the mirror. The birds responded by checking the relevant part of their own bodies and finding the previously unknown mark, which they then attempted to remove.
Only elephants, some cetaceans and great apes have previously passed this test.
Dogs fail the mirror test, but have been shown to be able to recognize their own smell as being their smell, maybe the same thing.
Recognizing Mind in Others
This is another very rare ability, as far as we know, in non-humans animals. However a number of bird species have been shown to be able to respond to others in this way. Male European Jays give food presents to their partners.
More than this they learn which food types make their partners happy and choose to give them their preferred items if possible.
Californian Scrub Jays (Aphelocoma californica) can reason that if another Jay has seem them cash some food they might later steal it. They respond to this (if they notice another jay in a position to observe them while they are caching food) by returning to the cached food soon afterwards and moving it to a different location. Interestingly they only do this, if they themselves have stolen cached items from another jay. It seems you need to be a thief to recognize another potential thief.
In 2016 a group of scientists showed that Ravens are aware that competitors need to see them caching items in order to be able to steal them.
When these birds were caching food items they took notice of whether or not other ravens could observe them, meaning a visual channel (a peephole) was open or not. If it was open and they could here ravens nearby the guarded they caches much more than if they could hear other ravens but see that the peephole was closed, meaning the other ravens had no possibility of observing them.
Play in Birds
Play is not uncommon in the animal kingdom. In general play is more common in young developing individuals rather than in adults, however adult play is not so rare among mammals and birds. Many captive birds have been observed to be playful. Scientists believe that play in young animals is an important method of learning skills that will be later used in adult life.
Play in adults seems to be about social interaction, and in some birds I cannot doubt that a sense of fun is involved.
Play among powerful animals requires not just a set of actions but mechanisms to ensure that the players do not get hurt. This means when adults play they exercise restraint, controlling the strength and severity of bites and blows. It also involves an awareness on both parties that the actions currently indulged in are play, not competition.
Ravens are well known to be playful creatures and have been observed doing a wide variety of playful actions including hanging upside down, playing with others in flight, playing with objects and vocal play, often involving mimicry.
I have observed Ravens playing on several occasions, one of these involved ravens flying in the turbulence of a cold front as it moved across the sky. They are also known to use play as a way of learning about the behaviour and future intentions of others.
The other involved a little studied bird called the White-browed Laughing Thrush (Garrulax sannio). I had these delightful birds as companions for four years while I was working in Qujing Normal University in Yunnan China. They are noisy, inquisitive and extremely social birds, constantly calling out to one another as they move through the trees and shrubbery.
On one memorable occasion, while I was trying to photograph a Taiga Flycatcher (Ficedula albicilla), I observed a group of White-browed Laughing Thrushes playing, what for all intents and purposes appeared to be a game of ‘follow the leader’. The five or six birds were following one another in a line. The lead bird performed a series of hop-jumps across a fallen branch (hopping up to, onto and then down from the branch) it then turned and watched as the following birds performed the same maneuver, then set off again and the whole group disappeared from view into the underbrush still in line.
I remain convinced to this day that these birds were playing, not foraging, as not one of them deviated from the course or pecked at the ground or made any other foraging actions as I watched.
As more research is done day by day, so our understanding deepens. This article has barely scratched the surface of bird intelligence, something that is beyond any doubt a fascinating subject. I encourage you to go further, look deeper and enjoy more fully the wonderful field that is the study of intelligence in other animals.
2020 Update
In a science paper published on September 24 2020 scientists at the University of Tübingen in Germany led by Professor Andreas Nieder report that crows are capable of consciously perceiving sensory input. This means they have the ability to have subjective experiences that can be explicitly accessed and thus reported. Until now this type of consciousness has only been witnessed in humans and other primates. So, we now have scientific proof that birds, at least crows if not others, experience consciousness in a manner very similar to ourselves. What is coming next I wonder?
Image Credits: Raven image by Yifei He, Grassquit image by Charles J Sharp, Two Ravens image by Colin, Californian Scrub Jay by V. J. Anderson, License CC BY-SA 4.0: Pigeon by Dori,Tree Shrew image by Hornbill, License CC BY-SA 3.0; African Gray Parrot image by Thomas Quine, Mawcaw image by I, Luc Viatour, License CC BY 2.0 – All Wiki Commons: Robin on a Mirror by Jordan Irving – Unsplash
Great resource! Fascinating examples of varying forms of intelligence across the bird kingdom.