Wednesday, 2 January 2013

Will Grey Parrots Share?

A fascinating study by Franck Péron and colleagues looks at the question of whether or not grey parrots (Psittacus erithacus) will share, with each other or with a human. Two hand-reared parrots took part: Griffin, the dominant bird who is 14 years old, and Arthur, who is 11. The birds live in large individual cages in the same room as each other, and often take part in studies of parrot cognition. This means they were well placed to understand the task involved: choosing one of four coloured cups, each of which has a different meaning.

For the purposes of this study, the cups were as follows:-
Green cup – sharing. The bird and their partner both get a treat.
Pink cup – selfish. The bird gets a treat but the partner does not.
Orange cup – giving. The partner gets a treat, but they do not.
Violet cup – null. No one gets a treat.

The treats varied, including pieces of cashew nut and almonds, and sometimes small candies. In the first experiment, the cups were arranged on a tray without the birds seeing what went under them. Two humans performed a demonstration session, so the birds could see what the results of different cup choices were. Then the experiment began.

A grey parrot (psittacus erithacus) looking at the camera
 
The tray was presented to the first bird, who had to make a choice, and treats were distributed accordingly. Then the second bird got to make a choice. In total, there were fifty sessions, in which each bird got to make ten choices. Griffin led in 24 of the sessions, and Arthur led in the other 26 (it was meant to be equal, but there was a mistake). 

The birds did not choose randomly, and nor did they co-operate by always choosing the sharing cup, which would have maximized the rewards for both of them. Griffin, the dominant bird, chose selfishly when he went first, but when he had the second choice he continued to sometimes share. Arthur became more selfish over the trials, whether he was leader or follower. And while Arthur was silent throughout, Griffin sometimes said ‘want nut’ or ‘nut’, or squeaked in a frustrated way, in response to his own or Arthur’s choices.

Of course, the parrots already had a relationship with each other which may have affected their choices. Perhaps Arthur became more selfish over time because, as the subordinate bird, it was unusual that he had a chance to do so without reprisal.

The second experiment was similar, except the birds were paired with several humans. One human was always selfish, one was always giving, and the other copied whatever the parrot had just done. In most cases, the birds had ten sessions of ten trials each (i.e. ten choices for the bird and ten for the following human), although there was some variability due to students’ schedules. The main difference was that for Arthur, towards the end, there was a three week hiatus in testing because of students’ exams.

As before, both birds avoided the giving and null cups. Griffin’s behaviour changed over the time of the trials. When the human was giving, Griffin began to share more over time. When the human was selfish, he became more selfish over time. With the copycat, it wasn’t clear that Griffin understood this, although there was a slight increase in sharing behaviour.

Arthur’s results were complicated by the three week gap in testing. He is a bird who doesn’t respond well to absences by people he is used to interacting with, and often greets them on their return by biting or shunning them. Prior to the gap, he was tending towards more sharing with the ‘giving’ human, but after the gap he reversed this behaviour. He also didn’t seem to like the copycat, and often chose the ‘null’ cup, which may have been his way of saying he had had enough.

These results show that Griffin seemed to understand the concept of sharing, since he tended to pick the ‘share’ cup more often with the ‘giving’ human (note that he wasn’t copying the human, because that would have involved picking the ‘giving’ cup). Both birds showed awareness of the value of the choices. Their choices changed over time and (at least to some extent) according to what their partner did.

One of the things I especially like about this study is that the parrots’ personalities shine through.

Do you have a bird at home, and if so what kind?

Reference

Péron F, John M, Sapowicz S, Bovet D, & Pepperberg IM (2012). A study of sharing and reciprocity in grey parrots (Psittacus erithacus). Animal cognition PMID: 23065183

18 comments:

  1. Great post! Animal behavior is a always a fascinating field showing us that animals are much more clever than we think.

    Regards,
    Piter K. Boll

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    1. Thank you! I agree - I love finding out about the ways in which animals surprise us.

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  2. Interesting. I have a Quaker and a Senegal who socially tolerate each other, and my Quaker might sometimes oblige the Senegal's request for head-preening but when he needs the favor back, the Senegal ignored him, bites him, or keeps demanding more attention for himself. I'm sure that's not remotely close to the level of the experiment you wrote about, but to me it just made the connection.

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    1. That's really interesting. I can definitely see the connection - instead of sharing (or not sharing) treats, it's sharing preening. I think preening behaviour is fascinating because of the social dynamics involved.

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  3. We have 3 birds at home. One CAG, one Umbrella too, and one orange winged Amazon. The Umbrella and the Amazon live together in a huge cage and frequently share their food with each other. The too often will share with my wife and me in the form of if we ask for a kiss when he has a treat either tucked under his tongue or in his beak we may wind up having the treat stuffed in our mouths. The CAG is another story. He is a food vacuum and wouldn't share with God himself.

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    1. I have to admit my first thought in response to the Umbrella too sharing his treats was 'ugh', but that's actually very sweet!

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  4. I do have a CAG. Before I had too a ´tiel, and they did share toys and even the CAG helped the ´tiel crashing walnuts impossible to open for him... when he passed away, the CAG kept naming him and mimicring all the funny noises and whistles the used to do. Surpinsingly, while alive, the CAG never mimic that noises.

    Very interesting blog you have.

    Congratulations.

    PS: I run a blog about psittacine training, quite focused in the science behind all of it, would you mind if I link yours in mine? Thanks.

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    1. It's interesting that the CAG copied the 'tiel in that way, but only after he was gone. I love the idea of the CAG helping him open the walnuts.

      Thanks for letting me know about your blog, I'll take a look at it. Yes, by all means put a link to my blog - thank you. This is actually the first time CAPB has had a story about parrots (mostly we focus on cats and dogs) but it's been so popular we'll definitely cover more parrot/bird research in the future.

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    2. It would be great, indeed, if you write more about these fascinating pets parrots are.

      Thanks.

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  5. I have two African Greys, Arrow ( 24) and Zachary (19) When Arrow, asks for somthing to eat she will remind me to also give Zachary what ever she has requested. Example:"Arrow want cracker" "Zachary eat cracker"

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  6. Color preference could have played a role.

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    1. I'm glad you brought this up because they actually tested for colour preference right at the start, before they gave any values to the cups. So you're right, it was an important thing to check, and they ruled it out at the beginning. I should also mention that the parrots were used to cups similar to the ones used in this study, but hadn't seen these particular cups before, so they didn't have any prior information about the cups.

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  7. hahaha Dotty hilarious Arrpw want cracker Zachary eat cracker.
    I have a congo grey girl ,a timneh grey male and a senegal parrot. Living with more than one grey parrot is so much fun, talking to me and each other in english. Each morning I give my birds a peanut and i have a coffee. When I walk past Dali congo grey girls cage to get my second cup she tells me "WANT SOME APPLE" She always tells me this in her demanding business voice but as soon as I open the fridge she leans over to the cage next to her where Quark senegal is and asks him in the most syrupy sweet voice " want some apple? Too funny.

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  8. That is so funny! I love it.

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  9. I have a yellow napped Amazon, and he DOESN'T like sharing - at all. If I'm trying to take his food bucket to refill it, he's being very angry about, despite I'm actually giving him more food.

    Or maybe he's just being weird as always. I wish he could share a little more love to me.

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    1. It sounds like he thinks you are taking food away, rather than giving him more! Perhaps that is why he is angry? He sounds like a real character :)

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  10. I believe they are capable of sharing and deciding on whether they want to or not. Cherry Grey started to play a game with me early on; when she was about 1 yrs old. She started the game, we call it "getchyou" and she will beak the back of my hand, and I will touch her skirt under or on the side of her body and she will scream. In delight actually. She made this game up herself, and we started to call it "GETCHYOU"...She will "get me" I will softly "get her" and so on. Then we end the game and she lowers her head for tickles as if to say OK I'm done with that game now. I think I got a sample on tape last week. We have a new stream up and we are documenting the Life of Cherry Grey. Please come follow her; on Livestream! I would love for Irene to see some of the things she responds to. I'm keeping a vlog of it all; it started last week. We are rolling out a new project to keep the feed fun for any watchers.
    http://new.livestream.com/cherrygrey/thecherrychannel

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