Animal researchers have turned to 'citizen science' to better understand the differences between dichromatic and trichromatic vision in animals, enlisting 30,000 volunteers to play a tailored online computer game. Jim Drury reports.
Most humans are trichromats - meaning we have three types of colour receptor cells in our eyes. But mammals are generally dichromats - with only two. British researchers want to know why. SOUNDBITE (English) VARIOUS OF LEAD AUTHOR DR JOLYON TROSCIANKO, SAYING: "A huge number of mammals, including the monkeys that we evolved from, are dichromats. But it doesn't take a huge evolutionary leap to develop this third colour channel. So it's surprising that this hasn't happened more often in Nature, suggesting there could be some advantage to being a dichromat." The team devised this online game in which 30,000 users scoured photos for camouflaged nightjar birds or nests containing eggs. SOUNDBITE (English) VARIOUS OF LEAD AUTHOR DR JOLYON TROSCIANKO, SAYING: "When people played the game they had a choice between playing as a trichromat, for example a monkey, or a dichromat, for example a mongoose. And this changed the simulated colours that they could see to make them effectively see through the eyes of one of the relevant predators for the nightjars or the ground nesting birds." The study showed trichromats found the nightjars and eggs faster....but the simulated dichromats' vision improved faster. SOUNDBITE (English) VARIOUS OF LEAD AUTHOR DR JOLYON TROSCIANKO, SAYING: "It was really fascinating from this project, finding that the dichromat that's learned over time to perform on a par with trichromats. That shows that there's a huge element of learning which has previously been largely ignored in the importance of camouflage. But if a predator in the wild is learning to try and find one type of prey one type of camouflage faster than another that could actually change the whole dynamics of an ecosystem where there's now a disadvantage to having a camouflage type that is easily learned by predators over time." The study could also be of military interest - shedding light on the art of camouflaging soldiers and equipment.