The parrots that understand probabilities

The parrots that understand probabilities


VOICE OVER: The kea is a particularly intelligent
species of parrot from New Zealand. Now, research suggests that these birds
might be smarter than anyone expected, even outperforming monkeys in some tasks. These kea can use probabilities to predict
which hand a black token is most likely to be in based on where the token is picked
from and on who is doing the picking, even combining information from different contexts. AMALIA BASTOS: The kea are great fun to work with. They are some of the most intelligent birds I’ve
ever met, and they all have amazing personalities. VOICE OVER: Amalia Bastos has been working with kea, trying to find out whether they
could predict uncertain future events. AMALIA: Could they understand an event that
happened with incomplete information? Could they fill in the gaps? So, if you imagine that I’m placing my hand into a jar with mostly blue candies and a few yellow candies, and I take something from that jar
but you can’t see what’s in my hand, you might guess that I’ve taken a blue candy, and
we wanted to see if kea could do the same thing. VOICE OVER: A group of captive
kea were taught that black tokens, and only black tokens,
could be exchanged for food. They then saw an experimenter take tokens from two jars, without being able to see what was in each hand. They chose a hand by tapping
on it to get the token inside. In the first experiment, the kea almost always preferred
the jar with the highest proportion of black tokens, even when the actual number of
black tokens in each was the same. This suggests they were choosing the hand based
on the probability of it containing a black token, something only previously seen in great apes. A second experiment showed they could even
take into account a barrier in the middle of the jar, looking for the jars with the highest proportion of
black tokens in the top section and ignoring the rest. AMALIA: So, kea have a complex social structure, where many individuals can live in a group
and they come and go as they please, and that means they need to remember
the identities of multiple individuals, and they have to interact with multiple individuals, and of course they need to remember all of these interactions. So, we wanted to see whether kea could understand
that experimenters have biases or preferences when they make their selections. For example, one might person might select a yellow
candy even when the yellow candy is in the minority, and another might select a yellow
candy when they’re in the majority. And what we can assume from that is that the person
who took yellow candy when it was in the minority actually prefers yellow candies to blue candies. VOICE OVER: The third part of the
experiment tested their social skills. The birds were shown two
humans taking tokens from a jar. One person looked into the jar and
deliberately picked one of very few black tokens. When later offered a choice of experimenters,
the kea remembered this person and their apparent preference for black tokens. AMALIA: We were very surprised
to find that kea can use social cues, even from humans, to make these judgements. Kea were looking at the biased experimenter, understanding that they had a bias or a
preference for a particular type of token, and then selecting this person at test when both
experimenters had the same populations of tokens. VOICE OVER: Reading human social cues like this and remembering information about
individuals to use when making predictions, is another ability that’s so far
only been shown in great apes. AMALIA: Kea look very intelligent
and they behave very intelligently, I just didn’t expect them to perform
quite as well as chimpanzees do. VOICE OVER: This experiment marks the first evidence that birds can make predictions
about future events using probabilities, and that they can combine information from
different contexts to make those predictions. AMALIA: I can’t wait to see what kea do
next because they keep surprising us, so I can’t wait to see what the next step brings. OK, Plankton can you move? OK, just a little bit… Planky! Can you move please? You can’t stand in front of the camera! Huh?