Birds can see more colours than humans, according to a new study published in June, including hues invisible to the human eye such as ultraviolet red and yellow.

The findings, based on a diverse sample of feather patches from 111 bird species, show that birds have an additional cone in their eyes responsible for colour vision.

These colour cones, are sensitive to ultraviolet light which is imperceptible to the human eye, according to the study out of Yale University and the University of Cambridge.

The joint study, published in Behavioral Ecology, applied a mathematical model to estimate the gap between what birds can see and the range of plumage colours observed by humans.

"Birds are among the most colourful organisms on the planet. To our human eyes, birds seem to possess almost every colour imaginable -- but birds see the world very differently than we do," Mary Caswell Stoddard of the University of Cambridge's Department of Zoology said in a press released published on Wednesday.

Stoddard and co-author Richard Prum discovered that the colours humans observe when looking at birds represent less than a third of the possible colours birds see.

"Birds can make only about 26 to 30 per cent of the colours they are capable of seeing," Prum said in the press release. "The startling thing to realize is that although the colours of birds look so incredibly diverse and beautiful to us, we are colour blind compared to birds."