LUND, Sweden, June 16 (UPI) -- New research confirms the ability of chickens to see in constant color.
Constant color is the ability to distinguish colors in varying light conditions. Scientists in Sweden were able to show that chickens can recognize different colors whether the sun is high, low or behind clouds.
As long as there is light, the birds can use their color vision to distinguish between ripe and unripe fruit, as well as recognize their peers.
"We studied many different lighting conditions to find out how big the changes in light could be without the chickens losing their color constancy," Peter Olsson, biologist a Lund University, said in a news release. "This type of study has never been done before."
Olsson and his colleagues trained chickens to prefer the color orange. Raised in white light, adolescent chickens were presented with differently colored containers, red, yellow and orange. Only orange yielded food.
As scientists alter the light in the room to different shades of red, the chickens remained focused on the orange container. Researchers used the experimental results to build a model that simulates a chicken's color vision. They published their findings in the journal PNAS.
The model will allow future researchers to compare color constancy among chickens, birds and other animals.
"We can also compare the chickens' color constancy ability in the laboratory to the light changes they and other birds experience in nature, such as how the lighting conditions differ in the woods from in an open field," explained Olsson. "Our results show that they are able to maintain their colour constancy under greater changes in light in the laboratory than when experiencing those that occur in nature."