Birds' food control is survival tactic, study shows

The New Caldedonian crows were offered meat and apple during the research

Crows behave differently around food when rivals are present, new research has found.

A study by Anglia Ruskin University (ARU) and the University of Cambridge discovered that Eurasian jays will settle for an immediate, less preferred food option when another bird is present - while New Caledonian crows will hold out for their favourite nibbles.

Co-lead author Rachael Miller, senior lecturer in Biology at ARU, said it demonstrated the "ability for self-control".

"Jays rely more on this tactic for their survival," she added.

Mealworms and bread were placed out for Eurasian jays in the study

During the experiment, a rotating tray task was presented to the birds with high and low quality food options, which they had to remove from under clear plastic cups.

Just before the less preferred food became available, a second bird was allowed in from a separate compartment.

The bird then chose to eat what was in front of it - or wait 15 seconds for the delayed, preferred option.

The study found that each jay selected the high quality mealworm, but chose the immediate food choice - bread - when either a competitor or non-competitor bird was present.

The crow "stood its ground" and waited for the high-quality meat over an apple in all three test conditions, researchers found.

'Sociable and tolerant'

Ms Miller added: "We have also used this rotating tray task to comparably measure self-control in young children.

"Interestingly, we found that jays were highly flexible in their use of delayed gratification, and this was entirely influenced by the presence of other birds, but the crows consistently chose the better, delayed reward, regardless of rival birds being present.

"New Caledonian crows tend to be more sociable and tolerant of others than Eurasian jays, and while both hide food for later use, jays rely more on this tactic for their survival."