Male Eurasian jays know that their female partners’ desires can differ from their own

jfp40 — Wed, 26 Mar 2014 10:52:41 +0000

Knowing what another person wants is not a trivial issue, particularly when the other’s desires are different from our own. ̽��ֱ��ability to disengage from our own desire to cater to someone else’s wishes is thought to be a unique feature of human cognition.

New research challenges this assumption. Despite wanting something different to eat, male Eurasian jays can disengage from their own current desire in order to feed the female what she wants even when her desires are different to his. ̽��ֱ��study, which was funded by the BBSRC, is published today in the Royal Society journal Biology Letters.

“We found that males could respond to the female’s desire even when their own desire was conflicting. That said, the males were also partially biased by what they wanted – a bias similar to one commonly found in human children and adults,” said Dr Ljerka Ostojić, who led the ̽��ֱ�� of Cambridge study.

For the study, nine male-female pairs of Eurasian jays (a member of the Corvid family) from two colonies were tested during the breeding season – the only time when jays share food. To manipulate what food the males and the females desired, the researchers used a phenomenon termed ‘specific satiety’ – after eating a particular food item to satiety, jays prefer to eat a novel food item that they are not currently sated on.

Once a day the females and males were placed in adjacent compartments with a mesh window in between. ̽��ֱ��male was then pre-fed either wax moth larvae or mealworm beetle larvae – both favourite treats for jays - until he did not want more. At the same time, the female’s desire was manipulated by giving her the same food as the male (meaning that their desires were matching), a different food from the male (meaning that their desires were conflicting), or her usual diet (meaning that the female’s desire was neutral towards the two types of larvae).

During the pre-feeding, the male had visual access to the female and saw her eat. At the end of pre-feeding, all food was removed. ̽��ֱ��males were then given 20 choices between a single wax moth larva and a mealworm beetle larva which they could either eat, cache (hide for later) or give to the female.

Not surprisingly, when the male and female birds’ preferences were the same, the male fed the female the food desired by both. However, when the female’s desire differed from the male’s, then he took his partner’s wishes into account, often feeding her the food that she desired. This ability to ascribe to another individual an internal life like one’s own and at the same time understand that the other’s internal, psychological states might differ from one’s own is called state-attribution.

Professor Nicky Clayton, whose Comparative Cognition lab at Cambridge ̽��ֱ��’s Department of Psychology conducted the study, said: “As humans, we ‘put ourselves into someone else’s shoes’ in order to respond to what the other person wants. Although we are biased by our own current desires, we can inhibit these to put the wants and desires of another before our own. ̽��ֱ��current findings show that the jays can also do this. So what this research suggests is that a common mechanism might underlie ‘desire-state attribution’ in humans and jays.”

New research shows that male jays are able to disengage from their own current desires to feed their female partner food that she wants.

We found that males could respond to the female’s desire even when their own desire was conflicting.

Dr Ljerka Ostojić

Male Eurasian jay

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Yes

Monogamous birds read partner's food desires

ljm67 — Fri, 15 Feb 2013 09:43:35 +0000

New research shows that male Eurasian Jays in committed relationships are able to share food with their female partner according to her current desire.

̽��ֱ��behaviour suggests the potential for ‘state-attribution’ in these birds – the ability to recognise and understand the internal life and psychological states of others.

̽��ֱ��research was carried out in Professor Nicola Clayton’s Comparative Cognition lab at Cambridge ̽��ֱ��’s Department of Psychology, and is published today in the journal PNAS.

Researchers tested mated jays and separated males from females. ̽��ֱ��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.

“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,” said Ljerka Ostojic, who led the research.

“Ascribing internal states to other individuals requires the basic understanding that others are distinct from the self and others’ internal states are independent from, and differ from, one’s own.

When there was no opportunity to feed the female, males chose between the two foods according to their own desires. Only when they could share with the female did they disengage from their own desires and select food the female wanted.

̽��ֱ��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.

“A comparison might be a man giving his wife chocolates. ̽��ֱ��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.”

Research suggests that Eurasian Jays might be able to determine aspects of the ‘internal life’ of their mate.

Our results raise the possibility that these birds may be capable of ascribing desire to their mates

Ljerka Ostojic

Eurasian Jay mating pair engaged in food-sharing

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

̽��ֱ�� of Cambridge - Ljerka Ostojic

Male Eurasian jays know that their female partners’ desires can differ from their own

Monogamous birds read partner's food desires