Science Interviews


Sun, 3rd Jun 2007

Clever Birds - How Scrub Jays Plan for the Future

Professor Nicky Clayton, University of Cambridge

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Chris - I'm very pleased to welcome Nicky Clayton from Cambridge University. Now Nicky you work on scrub jays, I understand that's a kind of bird, but perhaps you could kick off by telling us first of all what actually is a scrub jay and why would you want to work on it?

Nicky - Well, I work on a number of birds which are part of the crow family. This includes ravens and magpies and jays, and the ones that I work on are jays, rooks and jackdaws.Prof Clayton and Scrub Jays

Chris - But why are you particularly interested in this family of animals?

Nicky - Well, these birds are particularly clever. We think of them as the feathered Einsteins or the feathered apes of the bird world. They have huge brains for their body size and there are all kinds of examples of just how clever they are.

Chris - One of the things you did recently was to see how good they were at planning for a rainy day, so tell us about that.

Nicky - Well, these birds hide food for the future. We call this caching behaviour, from the French word to hide. What we were interested in was the extent to which they could plan, because obviously other animals hide food, like squirrels, and many animals hibernate or migrate which means they have a forward looking behaviour. But there is a difference between a simple forward looking behaviour that might be triggered by a seasonal cue which will be entirely inborn and actually planning which would require some sort of thinking or forethought.

Chris - So how do you know they're actually doing that?

Nicky - So what we did was we asked whether they could plan for tomorrow's breakfast, and this is an experiment that was actually done by two of my Ph.D. students. It was led by Caroline Raby with help from Dean Alexis, and a member of my department Tony Dickinson, so credit must go to them as well as to me. What we did was to ask whether they could plan for tomorrowís breakfast, so we taught them that there were a suite of room that they could visit during the day.

Chris - Like a bird motel or something?

Nicky - Thatís right, a bird motel with a suite of three rooms and in the evening they went to sleep in the dark just as all birds do and when they woke up in the morning, they found themselves in one of two motel rooms. On some days they found themselves in motel room 1, they woke up hungry and breakfast was served, so no problem. On other days however, they found themselves in motel room 2, which was unlucky because when they woke up hungry as usual, there was no breakfast. But then all of a sudden, we gave them an unexpected test, which was to give them the opportunity to hide food as well as eat it in the evening and all the birds put the vast majority of the food, in motel room 2, where breakfast wasnít served.

Chris - So they knew that they had been hungry there in the past so they were relying on this past experience to plan for tomorrow because they may be in motel room 2 and have no food.

Nicky - Exactly, but they hadnít been trained to hide food in either of these rooms, and they used their past experience about which rooms served breakfast in the morning and which didnít to solve a potential problem. They didnít know where theyíd be in the morning, so just in case, theyíd put the food in the room where breakfast isnít served.

Chris - Why do they have this trait, you can see why we might do that because we are a bit more complex than they are, but what benefit does it serve this family of birds to have this ability?

Nicky - Well, thatís a very interesting question from a number of levels; my husband, Dr. Nathan Emery and I have suggested that intelligence has evolved independently in two very different groups of animals: Apes, which obviously includes us, and members of the crow family. We think that this is because in the wild they have similar problems to solve, and they evolved around the same time as apes (around 5 million years ago), they are also highly social. One of the major theories formulated by Nicholas Humphrey is that the reason why we and other apes are so intelligent is because we live complex social lives. This is not just about living in a big group, but having to keep track of who does what to you and being able to network and do politics. The argument is that, those are exactly the type of problems that the members of the crow family solve.

Chris - I saw this piece in the Daily Telegraph this week, it says: ďA quick smoke is good for the wings. Birds are picking up discarded cigarette butts and using their smoke to fumigate their wings of parasites, experts have suggested. Rooks have been spotted swooping onto the tracks at Exeter St. Davidís railway station in Devon and then placing their wings over the smoke to collect the fumes. One commuter said: I noticed the rooks because they are not usually found in towns. They were generally flapping about when a chap flicked a cigarette butt onto the track. It was still alight, and one of the rooks swooped down, picked the butt up with its beak and they flew around and landed on the platform dancing around with a cigarette butt in its beak. It looked quite comical, but then it dropped the butt onto the platform, placed its wings over it, collecting the smoke. It seemed as though it was using it to get rid of something, like an ant or a parasite or something.Ē And then they got a quote from someone at the RCPB who said theyíve never heard about it but perhaps theyíd learn to use the cigarette smoke to kill off parasites.

Nicky - How very clever, Iíve got to go and see them. Iíve never seen that but of course rooks are renowned for doing a number of very innovative and seemingly clever things. One of the most famous examples is that a couple of years ago they won the award for BBCís cleverest animal. This was rooks on one of the M4 motorway service stations, and what the birds were doing was finding a very innovative way of getting food that was at the bottom of the rubbish bins on the service station. So two birds would sit in tandem on the opposite ends of the rubbish bin, and slowly pull up the bin-liner under their feet. They would do it in tandem so that all the food would go to the middle where itís within beak's reach and then one bird would start tossing the food over the side while the other bird popped down onto the pavement to guard the food so it couldnít be stolen by others.

Chris - And because no one has ever shown them how to do that, theyíve had to work that out for themselves and then teach each other, so one has had to look at what the other one is doing to work out how to do it?

Nicky - Well I guess the million dollar question is whether each individual bird works it out for themselves and it just so happens that lots of them do it, or whether they are actually learning from one another. Thatís very interesting and itís one of the kinds of experiments that we are starting to do at Cambridge University; to look at whether the rooks will learn from one another and whether you could actually get mini cultures depending of which individual bird is learning to do things in a particular way.

Kat - I think one of the most fascinating things that have come out of bird research recently is that they use tools, because you can associate humans or Chimps with using tools, but birds have beaks so why do they need to use tools? So tell us a bit about tool usage in birds.

Nicky - Well, your beak can only go so far, just in the same way that if there is a small hole, you canít get your hand in there, it may also be that the hole is sufficiently small or deep that the food is out of beakís reach and thatís when youíd need a tool. There are a number of species of birds that use tools, but the most remarkable thing is that one member of the crow family, the New Caledonia crow actually makes tools. So this sort of puts in on par with chimpanzees; they donít just use tools, they actually manufacture them, and they make different types of tools for different purposes.

Chris - Is there any clue given to us if you look at the animalís brains as to why these birds have these spectacular abilities compared with other animal that donít perform like this?

Nicky - Well if you look at the relative brain size, then obviously we have the biggest relative brain, but if you look at the next ones down itís the dolphins, but itís also the apes within the mammals and in the birds there are two groups, the crows and the parrots. If you look at where the enlargement is in the brain, just as in apes the enlargement is in the neocortex the same is true for the crows, the enlargement is in the avian neocortical area. So the same part of the brain is enlarged.

Chris - Thanks Nicky. Thatís Nicky Clayton from Cambridge University who works on Scrub jays and trying to use them to get insight into how they plan for the future and perhaps how our brains work too.


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