Our results raise the possibility that these birds may be capable of ascribing desire to their mates—acknowledging an ‘internal life’ in others like that of their own.”
– Ljerka Ostojic, researcher and coauthor of, Evidence suggesting that desire-state attribution may govern food sharing in Eurasian jays
A group of researchers at Cambridge University have discovered that a male bird, the Eurasian jay, can apparently cater to the current desire of its mate if it is in a committed relationship. Science Daily recently reported the details of the study:
Researchers tested mated jays and separated males from females. The females were fed one particular larvae, either wax moth or mealworm — a treat for the birds, like chocolates — allowing the males to observe from an adjacent compartment through a transparent window.
Once the pairs were reintroduced and the option of both larvae was presented, the males would choose to feed their partner the other type of larvae, to which she hadn’t previously had access — a change in diet welcomed by the female.
Through different tests using variations on food and visual access to the females during feeding, the researchers show that the males needed to actually see the females eating enough of and become sated by one type of larvae — called ‘specific satiety’ — to know to offer them the other type once reunited.
This demonstrates that the males’ sharing pattern was not a response to their partner’s behaviour indicating her preference but a response to the change in her internal state.
… The researchers believe that this ability to respond to another’s internal state in a cooperative situation might be important for species living in long-term relationships. Food-sharing is an important courtship behaviour for the Jays — so the ability to determine which food is currently desired by his partner might increase the male’s value as a mate.”
Similarly, With Humans…
While this information is all well and good for female birds, female women might wish to know if there is a correlation between male birds and men. Ostojic says,
A comparison might be a man giving his wife chocolates. The giving and receiving of chocolates is an important ‘pair-bonding’ ritual — but, a man that makes sure he gives his wife the chocolates she currently really wants will improve his bond with her much more effectively — getting in the good books, and proving himself a better life partner.”