Study shows monogamous birds can read partner's food desires

Feb 04, 2013
This is a Eurasian Jay mated pair engaged in food-sharing. Credit: Ljerka Ostojic

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

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

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

Researchers tested mated jays and separated males from . The females were fed one particular larvae, either wax 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 – 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, 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.

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.

"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."

Explore further: Two new species of yellow-shouldered bats endemic to the Neotropics

More information: "Evidence suggesting that desire-state attribution may govern food sharing in Eurasian Jays," by Ljerka Ostojić, Rachael C. Shaw, Lucy G. Cheke, and Nicola S. Clayton, PNAS, 2013.

Related Stories

'Paranoia' about rivals alters insect mating behavior

Aug 08, 2011

Scientists at the University of Liverpool have found that male fruitflies experience a type of 'paranoia' in the presence of another male, which doubles the length of time they mate with a female, despite the female of the ...

Female cowbirds prefer less intense male courtship displays

May 03, 2012

In most species, females prefer the most intense courtship display males can muster, but a new study finds that female cowbirds actually prefer less intense displays. The full results are published May 2 in the open access ...

Study of finches shows they form homosexual alliances

Aug 16, 2011

A new study by a team of researchers shows that for zebra finches, bonding trumps sex. Post-Doc fellow Julie Elie of the University of California and her team describe in the journal Behavioural Ecology an ...

Bisexual fish boost mating chances

Dec 12, 2012

In an unusual mating strategy, hard-up males of a tiny, promiscuous fish species engage in homosexual acts in a bid to entice females to copulate with them, a study said Wednesday.

Recommended for you

Offspring benefit from mum sending the right message

6 hours ago

(Phys.org) —Researchers have uncovered a previously unforeseen interaction between the sexes which reveals that offspring survival is affected by chemical signals emitted from the females' eggs.

Lemurs match scent of a friend to sound of her voice

21 hours ago

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

PosterusNeticus
not rated yet Feb 04, 2013
Are they yelled at when they bring home the wrong kind of tea?

More news stories

Adventurous bacteria

To reproduce or to conquer the world? Surprisingly, bacteria also face this problem. Theoretical biophysicists at Ludwig-Maximilians-Universitaet (LMU) in Munich have now shown how these organisms should ...

Revealing camouflaged bacteria

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so cal ...

How kids' brain structures grow as memory develops

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring ...

Gate for bacterial toxins found

Prof. Dr. Dr. Klaus Aktories and Dr. Panagiotis Papatheodorou from the Institute of Experimental and Clinical Pharmacology and Toxicology of the University of Freiburg have discovered the receptor responsible ...