Yep, this guy did it and it is quite fascinating; TED talk: https://www.ted.com/talks/joshua_klein_on_the_intelligence_o... Website: http://www.josh.is/crow-machine/
And also, this dutch startup is aiming at training crows to pick up cigarettes: https://www.crowdedcities.com/
Probably not. It probably seems like I'm shilling this researcher's blog in this thread at this point but this commentary [1] gives a short explanation of why.
One of my hobbies is actually bird watching, particularly with crows. I love the animals, they're very fascinating creatures. I've had the opportunity to interact with many of them because I set out peanuts for them near my neighborhood. They've very gradually become acclimated to this routine, and they reliably arrive to pick up food if I make a particular noise and they're in the area.
But I'm very skeptical that I could "train" them to start exchanging items for food. In captivity a crow's intelligence can be especially fostered and trained because there's no other source of food to distract it. If you want it to proceed through a puzzle [2] to get food it has to do so. But wild crows are very, very cautious and (like most animals) very economically rational in their feeding habits. To date none of the wild crows who give people items have been trained to do so, it's been a happy accident (it's never happened to me, unfortunately). If you start imposing an exchange system on the food dispensary, you might find that the crows simply go elsewhere for easier meals.
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1. I read somewhere about training crows to pickup cigarette butts in exchange food. I’ve always wondered if it would be possible to train a crow to pick up loose coins for food.
Surely that would depend on the exchange rate?
What seems not to have been mentioned so far is the difference between the economic rationality of an individual versus what happens when there's a large population of those individuals.
AFAICT, the goal of these projects isn't to train individuals but to train the population, in aggregate, perform the task.
It's not like crows are not willing to work for food. They have been documented breaking open stubborn mollusks by repeatedly flying them high above a road and dropping them until they crack, or throwing them under oncoming traffic to be smashed open.
The thing is that there are ample other food sources so whatever you provide needs to be truly exceptional insofar as rewards go. And the crows might not know it's a great reward until they solve the puzzle to get it.
I'm not saying it's impossible, I'm just pessimistic.
So... Can't this plan backfire too?
Side note: All the crows in Vancouver roost on a single street. Every day around sundown there are 10s of thousands of crows flying east and creating a chaotic scene at times. I’ve seen hundreds of crows ripping up a lawn looking for worms once and it felt like a scene from a movie. Here is a video of all the crows causing ruckus: https://m.youtube.com/watch?v=_QuEjaG4Ghs
Also we have one crow here in Vancouver who was raised by a human so he is essentially part of the population. He takes the sktrain, walks into McDonald’s and even stole a knife from a crime scene once. It’s an absolute hoot. He even has his own Instagram page: https://instagram.com/canuckthecrow