Do dogs see colors? Does this effect train our dogs in any way? These tend to be some questions that many educators and owners made, and that we will address in this article.
In early 1980, Roger Abrantes and colleagues conducted some tests at the Institute of Ethology from Cambridge to determine if the dogs saw in color or not, as popular opinion believed. The conclusion was that the experiments could distinguish between some colors and in turn, could not discriminate other colors. Dogs are not completely color blind (see only shades of gray).Some humans behave as they see certain colors, but not the entire color spectrum. However, at that time, they could not determine whether the color discrimination of dogs is due to the differentiation between the actual colors or various shades of gray. Now, recent research has shed some light on that experiment.
Dogs have two types of photoreceptors color, while humans have three. Thus, dogs probably perceive the world in different shades of yellow and bluish gray.
In the eye, the retina is cones, cells that capture light and also respond to color. Canids have fewer cones than humans, which means that, in principle, color vision may not be as accurate as ours. To see colors, we have several types of cones that can detect different wavelengths of light. Humans have three types of cones, sensitive to red light, sensitive to blue light and delicate to green light, which gives us the ability to record what we call full range or spectrum of color vision.
Studies by Russian scientists demonstrated that dogs tend to discriminate the real color instead of brightness signals. Dogs have an idea of dichromatic color, which means that they only have two types of cones in their eyes. Placental mammals are dichromatic. The ability to see long lengths necessary to distinguish red from the green wave, seem to have disappeared during evolution. However, the dichromatic vision is essential to identify colors in low light conditions, which favors animals nocturnal and crepuscular.
. Representation of the colors that humans can perceive as perceived against dogs
Photo: Dr. Cynthia Cook (Veterinary Vision Inc.).
Trichromatic species, like most human beings and primates, are three types of cones for color detection and can distinguish between 100 different color gradations. Bees are also trichromatic, but unlike primates, see ultraviolet, blue and green instead of blue, green and red. Instead some birds and fish are tetracrómatas, i.e., they perceive ultraviolet, blue, green and red colors.
The claim that dogs are blind to some colors is somewhat misleading. Some animals develop the ability to see some colors and develop others to see other colors, all depending on the mutations appeared and subsequent costs and benefits for their struggle for survival. In short, not to see certain colors can not be attributed to a defect but as an evolutionary and adaptive strategy that has improved, it's biological fitness.
Human: A and C. Dog: B and D. For the dog are difficult to discriminate between red and green.
What implications does this have for our communication and training our dogs? Because it 's hard to distinguish between individual red and green (as also happens to some humans), we must choose toys and training in other colors. For example, for a dog, blue or yellow are much easier to detect and consequently to differentiate colors. On the other hand, when training in any discipline odor detection, we use colors for objectives that are difficult to identify for them, forcing them to use their smell and not your eyes.