A new study has looked into the varying behaviour of corvids around food when other birds a present.
The research, conducted 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 – but New Caledonian Crows will hold out for their favoured food.
During the research, 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 study found that Eurasian Jay will settle for an immediate, less preferred food option when another bird is present (Carl Bovis).
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 however "stood its ground" and waited for the high-quality meat over an apple in all three test conditions.
Co-lead author Rachael Miller, senior lecturer in Biology at ARU, said it demonstrated the "ability for self-control".
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."
Miller, R, Davies, J R, Schiestl, M, Garcia-Pelegrin, E, Gray, R D, Taylor, A H, and Clayton, N S. 2023. Social influences on delayed gratification in New Caledonian crows and Eurasian jays. PLoS ONE. DOI: doi.org/10.1371/journal.pone.0289197