The idea that red makes a bull see red is one of the most familiar animal beliefs there is, and it is wrong. Bulls don’t see red as a vivid, standout color at all.1Science Questions with Surprising Answers. What is it about red that makes bulls so angry? The bull in the ring really does charge, but what sets it off is the motion of the cape rather than its color.2STEAM Ahead. Mythbuster: Do Bulls Hate the Color Red? The red matters more to the people in the stands than to the animal in the ring.
What Colors Can a Bull Actually See
The back of the eye contains cones, cells that sense color. People with normal vision have three types, tuned to blue, green and red light. Cattle, goats and sheep have only two working types,3PubMed. Photopigment basis for dichromatic color vision in cows, goats, and sheep which gives cattle two-color vision, like many other hoofed animals.4PubMed. Photopigment basis for dichromatic color vision in cows, goats, and sheep One type responds best to blue-violet light and the other to yellowish-green light.5Cambridge Core. Photopigment basis for dichromatic color vision in cows, goats, and sheep
Bulls lack the red-sensing cones but keep the blue and green ones.6Science Questions with Surprising Answers. What is it about red that makes bulls so angry? Their vision resembles that of a person with one type of red-green color blindness, so a red cape looks yellowish-gray to a bull.7Science Questions with Surprising Answers. What is it about red that makes bulls so angry? Reds, oranges and browns blur into similar dull tones for a bull, while blues stay fairly distinct.
Colorblind doesn’t mean seeing in black and white. Bulls see color, just across a narrower range than people do.
Bulls aren’t unusual here. Dogs also have two cone types and similar limited color vision.
Color is only part of vision, too. Cattle also judge how light or dark something is against its background, and that contrast helps them notice objects.
The Experiments That Tested Red Against Movement
When red, white and blue flags were waved in front of a bull, it charged the one that was moved the most, whatever its color.8STEAM Ahead. Mythbuster: Do Bulls Hate the Color Red? In a televised test, stationary red, white and blue flags drew equally fierce charges.9mythresults.com. Episode 83: Bulls, Borax, Bullets When the flags were then moved on a remote-controlled line, movement decided what the bull went after.10mythresults.com. Episode 83: Bulls, Borax, Bullets
Dummies told the same story. With dummies dressed in different colors, one bull charged the white one first, the blue second and the red last.11mythresults.com. Episode 83: Bulls, Borax, Bullets A person standing still in a red jumpsuit was ignored, while two cowboys moving around the ring drew the bull’s chase.12mythresults.com. Episode 83: Bulls, Borax, Bullets In another test, a still person in red drew no interest until they began to move.13STEAM Ahead. Mythbuster: Do Bulls Hate the Color Red?
These were demonstrations with few bulls, not large studies. Their results match what the eye science predicts, and together they make color an unlikely trigger, though individual bulls vary.
Why Movement Triggers a Charge
The aggressive whipping of the cape is what irritates the bull.14Centre of the Cell. Are bulls enraged by the colour red? Its brain links that sudden movement with danger, so its fight-or-flight response, the body’s automatic reaction to threat, kicks in and adrenaline is released.15Centre of the Cell. Are bulls enraged by the colour red? The bull then charges to drive off the threat.16Centre of the Cell. Are bulls enraged by the colour red? Cattle evolved as grazers watching for predators, and spotting something moving fast matters more for survival than noticing its hue.
Adrenaline speeds the heart and sends more blood to the muscles, preparing the animal for sudden, powerful effort. It also sharpens attention on whatever set off the alarm, which is why a bull may fixate on the cape. The same surge can push an animal toward fleeing instead of charging, so the threat response doesn’t always mean attack.
Human anger is a feeling, but what researchers can observe in a bull is a defensive reaction to something it reads as dangerous. The charge is aimed at the moving object, which is why the bull follows the cape rather than the person holding it. Calling it rage feeds the myth, because it suggests the bull is reacting to a provoking color rather than to a perceived threat.
Breeding and hormones add to the picture. Fighting bulls come from a breed selected over generations for a combative trait breeders call bravery,17Abanico veterinario. Analysis of Lidia cattle behavior. Influence of handling and selection so they are more ready to charge than an average farm animal. Bulls whose testosterone was lowered by a hormone-blocking vaccine were less aggressive,18Cambridge University Press. The effect of different levels of gonadotropin-releasing hormone antibody titres on plasma hormone concentrations, sexual and aggressive behaviour, testis size and performance of bulls which suggests testosterone helps make an intact bull more aggressive than a steer.
The bull in a bullfight has also already been through a lot. By the time the matador brings out the small red cape, it is stressed and agitated, and noise, crowds and the earlier stages heighten its reaction.
So Why Is the Matador’s Cape Red
The small red cape used in the final stage of a Spanish bullfight is called the muleta. Its red color is a matter of tradition,19Wikipedia. Spanish-style bullfighting and the bright red helps mask blood stains.20Wikipedia. Spanish-style bullfighting So the red is chosen for the spectators rather than the bull.21Under The Moonlight. Why A Red Cape Means Nothing To The Bull In A Bullfight Earlier in the fight, matadors use a bigger cape, often magenta and yellow. When the cape is flicked, the matador uses its swing and position to guide where the bull runs, which works because the bull follows motion.
The myth spread because people saw red capes and charging bulls together and linked them. Phrases like “seeing red” reinforced the idea, and few observers knew anything about cattle color vision until scientists measured it.
Is It Safe to Wear Red Around Bulls
Wearing red won’t provoke a bull, given how bulls see color. Sudden movement can. Calm, clear, unthreatening movement keeps a bull’s threat response from switching on,22Ag Proud. Safety tips when working around bulls and calm handling prevents many bull-related injuries.23Ag Proud. Safety tips when working around bulls
Before entering a bull’s pen or pasture, have an escape plan.24Ag Proud. Safety tips when working around bulls Let the bull know you’re there calmly and quietly, because surprising a bull is a bad idea.25Ag Proud. Safety tips when working around bulls Avoid running, waving your arms, or flapping coats or bags near a bull.
If you’re choosing what to wear for a farm visit or a walk through pasture, color is a poor basis for the decision. Think instead about whether clothing flaps, swings or rustles, since loose coats and dangling bags create the kind of motion that startles cattle. Snug, quiet clothing that doesn’t catch on fences also helps you move steadily if you need to leave.
Livestock facilities are designed to remove sharp contrasts, sudden shadows and visual clutter that startle them.26aces.illinois.edu. Temple Grandin’s mind is a gift to livestock and humanity Handlers aim for even, soft lighting with few shadows or bright spots.27Professional Animal Scientist. Livestock Handling Systems Sharp shadows on the ground make cattle more likely to stop,28Frontiers in Animal Science. The Visual, Auditory, and Physical Environment of Livestock Handling Facilities and Its Effect on Ease of Movement of Cattle, Pigs, and Sheep and solid walls that hide moving people and vehicles help cattle move forward calmly.29Frontiers in Animal Science. The Visual, Auditory, and Physical Environment of Livestock Handling Facilities and Its Effect on Ease of Movement of Cattle, Pigs, and Sheep
On a public footpath through a field with a bull, keep to the edge and move steadily, not hurriedly. Don’t approach or try to photograph the bull close up. Keep dogs on a lead, since a darting dog is fast movement. Know where the nearest gate or fence is before you cross.
A bull that is becoming agitated may lower its head and turn side-on to show its size. It may paw the ground or snort. If it starts walking toward you steadily, leave calmly at once.
Cows and steers aren’t always safe either. Cows with calves can be protective and charge, and any startled cattle can trample in a panic. The same calm, quiet rules apply to the whole herd.
If a bull begins to approach, don’t run. Sudden fast movement is the thing most likely to turn a curious or wary bull into a charging one. Walk away calmly, keeping the bull in view where you can, and head toward the nearest gate or fence you already identified. If a bull is clearly pursuing you, putting a solid barrier between you and it matters more than the direction you were originally heading.