Study shows crows able to infer actions of hidden agent

Sep 18, 2012 by Bob Yirka report
Corvus brachyrhynchos or Corvus caurinus. Image: Wikipedia.

(Phys.org)—The more scientists study animals and their intellectual abilities, the more it appears that many of them have heretofore unknown abilities that can match some of our own. One such animal is the New Caledonian crow which has been found to not only make and use tools, but to fashion them depending on which bird "culture" it happens to live in. The unusually big brained bird has also been found to live in nuclear families and some observers have suggested they even have some degree of affection for one another. For these reasons, a team of researchers from several countries got together to study their inferential skills, and as they describe in their paper published in the Proceedings of the National Academy of Sciences, they found the birds had an ability that until now was thought limited exclusively to us humans.

To find out if the birds are able to infer that actions taken behind a screen are the result of some known agent; an inferential skill, the team set up an experiment where the birds first used a stick to get at some food in a box; an exercise that has been demonstrated many times before with New Caledonians. Next however, they threw in something new, a blue sheet of plastic that the birds could not see through. The researches put it near the side of the cage that held one bird at a time, near to where the food box sat. They then stationed a person behind the sheet who pushed a stick through a small slit in the plastic, disrupting and upsetting the bird, preventing it from eating. That set the stage.

To find out if the birds could understand that it was a person manipulating the stick, without actually showing them, they let them see a person first walk behind the screen, observe the stick suddenly poking through at them then stop and then the person reemerging from behind the screen. Turns out, they could. They found this out by adding new twists to the test, such as letting them watch a person simply walk behind the screen to see how they'd react, or by not letting them see the person go behind the screen before wiggling the stick. The crows demonstrated they understood what was going on by avoiding the food box if the stick wiggled in any scenario, until they saw the person get out from behind the screen and walk away, indicating that it was safe to proceed. This the researchers say, proves that the truly understood that it was a person behind that screen wiggling that stick even though they never actually saw them do it. They had to infer that information, and that is something, the team reports, that has never before been observed in any other animal, besides people.

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More information: New Caledonian crows reason about hidden causal agents, PNAS, Published online before print September 17, 2012, doi: 10.1073/pnas.1208724109

Abstract
The ability to make inferences about hidden causal mechanisms underpins scientific and religious thought. It also facilitates the understanding of social interactions and the production of sophisticated tool-using behaviors. However, although animals can reason about the outcomes of accidental interventions, only humans have been shown to make inferences about hidden causal mechanisms. Here, we show that tool-making New Caledonian crows react differently to an observable event when it is caused by a hidden causal agent. Eight crows watched two series of events in which a stick moved. In the first set of events, the crows observed a human enter a hide, a stick move, and the human then leave the hide. In the second, the stick moved without a human entering or exiting the hide. The crows inspected the hide and abandoned probing with a tool for food more often after the second, unexplained series of events. This difference shows that the crows can reason about a hidden causal agent. Comparative studies with the methodology outlined here could aid in elucidating the selective pressures that led to the evolution of this cognitive ability.

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baudrunner
2.3 / 5 (3) Sep 18, 2012
Crows are a lot smarter than that. It seems that researchers are trying to pull intelligent behavior from creatures they assume are not intelligent. That's like talking baby-talk ("goo-goo gaa-gaa") to a baby. Why not just speak English to them? They are people after all. Same with crows. Assume that they know what you expect of them and you will get results. Don't waste time, you'll just confuse them.
ScooterG
3.1 / 5 (7) Sep 18, 2012
Crows are the epitome of coolness.
Jonseer
2.5 / 5 (2) Sep 19, 2012
The only reason this is such a surprise to them is they obviously haven't had any contact with birds on a personal level.

Recently I learned about Seramas, a dwarf breed of chicken.

Soon after I had an opportunity to get one, a rooster who now fully grown weighs about 1 lb, about 1/10 to 1/20th of the normal sized rooster. I can hold him in one hand.

I have been quite surprised by how profoundly intelligent he is.

Prior to having him, I thought of chickens as dumb birds who make funny noises.

My firs surprise was how NOT funny their clucks and sqwaks were.

Instead of being typical bird noises, his chatter has a cadence that mimics the tenor of a situation.

Give him good food,and he sounds like a human talking about a great meal for example.

The cadence of his sounds reflect specific emotions that eerily are appropriate for the situation, like being upset I fed him late LOL

Really they didn't have to got so far to find intelligent birds. They could have gone to a farm.
VendicarD
2 / 5 (1) Sep 19, 2012
If a red light blinks for several seconds, the crows have learned that the food will be unavailable until the green light blinks for several seconds.

From this the researchers conclude that the crows have deduced the hidden malevolent acts of blinking red lights.
baudrunner
1 / 5 (2) Sep 19, 2012
I actually rescued a young crow, not quite fully fledged, a couple of months ago, by picking her up from an office building entrance-way and placing it under some brushes in a raised planter between the building and a townhouse. Its parents were excitedly squawking from the trees close by while I was doing this. I am sure that they continued to look after their young one because I walk all around the downtown area of Vancouver and a certain young crow is often never far from me, and will sit close by when I am on a bench on the seawall or in a park playing my guitar. I have named her Crawley. Crows can establish close relationships with people without the need to reinforce that relationship with reward.