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Our paper 'Innovative Problem Solving in Macaws' has now been published in 'Learning and Behaviour' https://rdcu.be/cbQZN . Heres a thread of what we did: 1/19
We wanted to see if two species of macaw could innovate a novel way to push a reward out of a tube after first being shown that a pre-inserted stick could do this job. 2/19
So the subjects were first allowed to push this stick themselves to experience how it interacted with the reward and could be used to push it out of the tube: 3/19
We then gave them the same apparatus but without the pre-inserted stick, and instead gave them a selection of rocks to see if they could create a functional "tool" out of these components: 4/19
1 blue throated macaw (n=8) was able to solve the task at this stage, but none of the great green macaws (n=9) were able to. It wasn't a smooth process for the successful individual (Lady). 5/19
Here is Lady's success in graphical form. Each bar either side of the y-axis shows the number of stones she inserted in each side of the tube in each trial. Ergo, she only made the multi-stone tool without a mistake on 4/12 occasions. (trials 7,8,11 & 14) 6/19
For the subjects that weren't successful, we gave them this 'short tube' apparatus where they only had to insert 1 stone to get a reward. Many could do this, so we gave them another go at the full size apparatus to see if they could succeed after this more direct experience. 7/19
2 more subjects succeeded at this stage (Enya and Captain), 1 of each species. Here's a video of Enya making it look very easy: 8/19
Many other subjects inserted stones into the apparatus at this stage, however they inserted them from both sides of the apparatus, trapping the reward in the middle. This suggests they did not recognise the required function of the multi-stone construction they needed. 9/19
I wanted to know to what extent Enya, Lady and Captain understood the function of the multi-stone construction they were making. So we gave them an additional transfer task where there were two tubes present, one containing a reward and the other unrewarded. 10/19
Enya and Lady repeatedly inserted stones into both tubes, suggesting that they were probably using a very simple heuristic of just 'insert stones into one side of tube' rather than recognising they need to specifically target the multi-stone construction at the reward. 11/19
Captain, however, consistently targeted the multi-stone construction towards the rewarded tube only, suggesting he was at least using a more complex heuristic of 'create the multi-stone construction towards the reward'. 12/19
Finally, to further see Captain's understanding of his behaviour, we gave him this blocked tube transfer task. Again, there were two tubes, but now both were rewarded. However, one of the tubes was now blocked at one end so you could not push the reward out of it. 13/19
This proved a bit too much for Captain and he could no longer consistently succeed. Nevertheless, the blocked tube did not appear to be the MAIN reason he failed, he actually started to frequently make the mistake of placing rocks in both ends of the 'correct' tube. 14/19
Overall, it seems unlikely that any of the subjects had an understanding of the properties of what made the multi-stone construction functional. But we did learn a bit about how macaws explorative nature can lead to what looks like quite complex innovative behaviour 15/19
You may have noticed a vertical tube on top of the apparatus. This was a red-herring. It didn't do anything. But all the subjects inserted stones into it at many stages of the experiment. This was probably because this was a successful behaviour in a previous experiment. 16/19
All of these subjects had previous experience that dropping a stone into the top of another apparatus led to a reward in the stone dropping task (pre-print of that is out) 17/19
So it was neat to see how persistent many of the subjects were with applying this previously learned behaviour to another apparatus. Previously learned behaviours appeared to target their exploration and never really extinguished. 18/19
Thanks for reading that very long thread. If you're really REALLY keen then there are extensive videos and the date available on figshare as well: https://doi.org/10.6084/m9.figshare.12349418.v2 19/19
There were more videos to this thread, but twitter said it couldn't upload them at the last minute.
