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Cool Creatures

What are you thinking about, bird brain?

Most people would probably be offended to be called a ‘bird brain’, but depending on the bird in question it might not be quite so much of an insult. Although intelligence is often one of the traits that many would feel distinguishes us from other animals—pretty much any of the features that you might choose to define the concept of ‘braininess’ can be seen in other non-human animals.

Crows together with their relatives: ravens, magpies and jays, represent some geniuses from the animal kingdom. This family of birds—which together are called corvids—have attracted the attention of people interested in animal intelligence, because of their ability to make and use tools, to solve problems, and also to plan ahead for their future.


Crows, and other related birds, will hide excess food to be eaten at a later date | Image credit: BS Thurner Hof (CC-BY-SA)

Just like a squirrel storing up acorns for the winter, crows and their kin will store excess food, such as meat or nuts, to eat at a later date—an activity known as ‘caching’, with the food that is stored being called a ‘cache’. However, these caches are vulnerable to be being raided by thieves or pilferers. The main offenders are often other food-caching birds, including those of the same species, who were around at the time the cache was made. These birds can use the same skills used to remember where the hide their own caches—a keen pair of eyes and a good spatial memory—to watch were their victims hide their food, remember the locations, and return later to steal the food.

However, since these birds continue to store food in this way, more often than not, this activity must return a benefit to the food-caching individual. This is the case, because these brainy birds use clever strategies to protect their own caches—strategies that appear aimed to outwit the would-be-pilferers. Their tactics can be grouped as: those where the food-caching bird tries to withhold information about their food cache, or those that use misdirection and deception to ‘fool’ potential pilferers—although birds commonly use a mixed approach to protect their food stores.


Crows will often collect food from shared feeding sites, but hiding this food nearby will put it at risk from potential pilfering by the other birds | Image credit: Irene Stylianou (CC-BY-SA)

Common ravens have been seen to wait until other birds are not watching them before hiding their food, and European magpies (which have one of my most favourite Latin names ever, Pica pica) will fly away to find a secluded spot to hide their caches. Intuitive as these strategies, they are time-consuming and hence limit the bird’s ability to exploit a valuable food source. More subtle strategies allow birds to cache food in secret, even when other birds are around.

Western Scrub Jays—which are native to the western part of North America—will prefer to hide behind obstacles, such as trees or rocks, so the can cache in spots that are just out-of-sight of any nearby competitors. Further when such barriers are not an an option, and other birds are around, these scrub jays will tend to cache in the shadows, such that potential pilferers have a hard time seeing exactly where the food is hidden.


Western Scrub Jays are distinctively coloured in blue, white and grey; and will store food at scattered locations within their territories | Image credit: Samsara (CC-BY-SA)

Other cache-protection strategies appear even more cunning. Some birds will pretend to make a food cache when being watched but hide something inedible, like a stone, in an apparent attempt to mislead the observer. Others are known to return to caches that they had previously made in the presence of other birds, and move the food to a new location in secret. This so called ‘re-caching’ strategy is very selective and birds will prefer to move food that has been hidden when they were being observed, rather than those that were made in private. This selectivity has lead many researchers to consider that food-caching birds might be able to understand what other birds can ‘see’ or ‘know’.

Thoughts about thoughts’ are an aspect of something that is commonly called “theory of mind”. This is the ability to attribute and reason about your own thoughts, beliefs, or memories, as well as those that might be held by others. We use this ability when we try to see something from someone else’s point of view, and although it is something that many people will take for granted, this ability is really quite impressive. For example, young children can really struggle to understand anything from someone else’s perspective—as theory of mind doesn’t really develop until about 3 – 4 years of age.

But do the actions of food-caching corvids genuinely demonstrate that they have this kind of intelligence? This is something that I have thought about before, and even wrote about on this exact question as part of my undergraduate degree. Now, just as I concluded back then, the answer is still the same: nobody really knows!

Image credit: Stuart King (CC-BY)

The cover of my Major Course Assignment, from 2008, featuring (what I considered to be) a rather thoughtful-looking Western Scrub Jay  | Photo by Stuart King (CC-BY-3.0); Original image credit: Noël Zia Lee (CC-by-2.0)

The lack of progress is not because people are not still trying to answer this question, but because in most experiments it would be very difficult to tell whether, or not, a bird was really displaying theory of mind. The obvious problem is that, unlike us, these birds cannot talk to us and tell us what is going on within their heads. Nor are the researchers interested in this behaviour mind readers; and so they have to rely on watching an animal’s behaviour to try to work out what or how it may be thinking.

Likewise, the birds themselves cannot read each other’s minds. Even if they did have theory of mind, they too must rely on what they can observe in the behaviour of other birds to understand what another individual may ‘think’ or ‘know’. As such, if cache-protection strategies are being deployed in response what a bird can see; how can we tell if the bird is also translating this information into the concept of a ‘thought’ hidden away in the brain of another individual? And would a bird really need to do this to achieve the same results? Designing an experiment that would genuinely allow us to distinguish between a bird with theory of mind, and one that only responds to observable behaviours seems almost like the holy grail of the study of animal intelligence. However, if we did manage to achieve this, it might end up shedding more light on understanding what is going on in our own heads too.


Interesting Links

If you want to find out more about these brainy birds and their tool using skills, be sure to check out these links featured in Malcolm M. Campbell’s recent Tweets. Also, if you don’t already follow him on Twitter @m_m_campbell – you should take measures to correct that oversight ASAP!


About StuartKing

Hi, I'm Stuart, an Assistant Features Editor at eLife and recent life sciences PhD graduate. I blog about evolution and its weird and wonderful creations.


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