Tomorrow is Today

More Proof of Animal Consciousness: Scientists Observe Theory of Mind Among Corvids

You might think that, to a bird, one meal is as good as any other. But at least for jays, you’d be wrong. The birds actually aim for variety when they make caches of food to eat later, trying to ensure they’ll have a mixture of food to enjoy the next day.

The researchers confirmed that Eurasian jays have a similar desire for variety. If researchers pre-fed the jays a meal of wax moth larvae and then offered them a mix of that and mealworm larvae, the birds preferentially ate the mealworms. If the researchers did that after a meal of bird food, the birds chose the wax moths at a greater frequency.

When males were given the chance to present foods to their mates, they acted as if the female had just been given bird seed—they gave their mates a mixture of wax moths and mealworms. But if the males had the chance to watch their partners being fed a bunch of wax moths, their gifts shifted, and mealworms were presented with a much higher frequency.

This eliminated the possibility that the female somehow signaled the male to indicate which treat she preferred (if that were the case, it wouldn’t matter whether the male watched her eat before hand).

The one remaining possibility the researchers considered is that the male ended up feeling satiated with wax worms just by watching the females chow down on them. But the males showed identical feeding behaviors whether they watched their partners eat or not.

The researchers conclude their experiments show these birds are capable of attributing a specific mental state to others (namely, desiring a mealworm). They base this on the fact that the males weren’t simply giving the females what they wanted. In other words, their frequency of gift types didn’t match the frequency at which they ate. In addition, they note the females didn’t provide any signals that the males used to determine what to feed them. With those two possibilities eliminated, the authors conclude that the males were inferring the desires of the females.

(via Birds infer their partner’s desires during bonding ritual | Ars Technica)