Goats have long been kept as farm animals for their milk, meat, and fiber. As prey animals, their senses have evolved to be highly attuned to their surroundings. This includes excellent eyesight that allows them to see a wide range of colors. But can goats see the color purple? Read on to find out.
Goat Vision Basics
Goats have horizontal slit-shaped pupils that give them panoramic vision covering about 320-340 degrees. This allows them to easily scan the horizon for potential threats while grazing. Their eyes are positioned on the sides of their heads, giving them a wide visual field with a small binocular overlap of about 20-60 degrees in front of them.
Goats, like sheep and cattle, are dichromats, meaning they have two types of color receptor cones in their retinas. This allows them to see some colors in the blue to green to red range of the visible light spectrum. But they lack the third cone type that allows trichromatic animals like humans to see the full range of colors.
| Animal | Cone Types | Color Vision Ability |
|---|---|---|
| Human | Blue, Green, Red | Trichromatic – sees full color spectrum |
| Goat | Blue, Green | Dichromatic – sees blue to green to red range |
Despite having only two cone types, studies show that goats can discriminate between colors in the blue, green, yellow, grey and red range. Their color perception is limited compared to humans, but they are not completely colorblind.
Can Goats See Purple?
Purple is a secondary color made by combining the primary colors blue and red. To see purple, an animal must be able to see wavelengths of light in both the blue and red range.
Goats have blue cones that allow them to see short wavelength blue light. But they lack red cones to see the longer red wavelengths. This means they cannot see the full spectrum of light that makes up the color purple.
However, goats can see some shades of purple that appear more blue or lavender. Their blue cones allow them to detect these purple-blue hues. But purples with more red undertones likely appear dark or grey to a goat’s dichromatic vision.
| Color | Appears to Goat As |
|---|---|
| Blue-purple | Blue |
| Lavender | Light blue |
| Violet | Dark grey |
| Magenta | Dark grey |
So while goats cannot see the full spectrum of purple shades, they are able to see some bluish purples due to their blue color perception. But other purples with more red in them likely appear dark and dull.
Goat Behavioral Response to Purple
Research on goat vision and color perception is limited compared to primates and other mammals. But some studies provide insight into how goats behaviorally respond to the color purple.
A 2016 study trained goats to discriminate between pairs of colors for a food reward. Goats were able to distinguish blue from purple paired with grey. This indicates they can see some difference between blue and purple, likely the blueish purples.
Another study in 2008 found that goats prefer blue and show an aversion to yellow and red. When presented with purple next to grey, goats showed no preference between the two colors. This further suggests they do not see the aspects of purple that appear more reddish.
While more controlled studies are needed, this early research demonstrates goats can see bluish shades of purple but not the full range of purples humans perceive. Their lack of red color vision limits their ability to distinguish reddish purples.
Factors That Influence Goat Vision
Several factors influence a goat’s ability to perceive color, including breed, age, and health conditions.
Breed Differences
Some goat breeds may have better color discrimination than others. Goats originated in the Middle East and northern Africa, where their dichromatic vision was well adapted to the semi-arid environment. But as goats spread around the world, some may have developed enhanced vision abilities.
A 2014 study found that Brazilian goat breeds Moxotó and Canindé had better color perception than European breeds. Additional genetic and anatomical research is needed to understand breed variations in goat color vision.
Age-Related Changes
Young goat kids have reduced visual abilities that improve with age. At birth, their eyes are not fully developed. Colors appear washed out and they have limited visual acuity.
From 1-2 months of age, goat kids’ eyes undergo rapid development. Visual acuity, color perception, depth perception and peripheral vision improves substantially by 2-3 months old. By one year old, goats have reached full visual maturity.
As goats age, they may experience degenerative vision changes that can impair color perception. Cataracts, a leading cause of blindness in older goats, can create vision problems including diminished color discrimination.
Health Conditions
Certain health conditions can also impact a goat’s vision and color perception, including:
- Vitamin A deficiency – reduces rod function affecting night vision
- Uveitis – inner eye inflammation causing blurred vision
- Diabetes – can damage retinal blood vessels
- Intestinal parasites – can cause inflammation impairing sight
Any disease or deficiency affecting the eyes or optic nerve can potentially disrupt a goat’s color vision, including their limited ability to see shades of purple.
Do Goats Have a Favorite Color?
Research into goat color preference shows they gravitate toward blues and blues greens and avoid reds and yellows. Blues and greens are prevalent in the goat’s natural environment among vegetation and sky, while red and yellow can signal toxicity.
Given their partial ability to see bluish purples, goats may favor these purple-blue hues over redder shades. However, more controlled experiments are needed comparing goat reactions across the full purple spectrum.
Based on current evidence, blue appears to be the goat’s favorite color, with lavender and lilac shades of purple also ranking highly. But their lack of red cone receptors likely make goats indifferent to redder purples.
Conclusion
In summary, while goats cannot see the full range of purple due to their dichromatic vision, they are able to perceive some bluer shades of purple in the lavender to lilac range. However, purple colors with a higher red component likely appear dark and dull to goats. Their visual response to purple compared to blue and red colors demonstrates that goats have limited purple color perception. Additional factors like breed, age and health impact a goat’s vision and can further limit their ability to distinguish purples. So while goats may enjoy munching on purple flowers, their color experience of those blooms is not as vibrant as the human eye can appreciate.