Improving racecourse fence visibility for horses

Research into the colour of racecourse jumps have now been published. It was commissioned by the British Horseracing Authority (BHA) and Racing Foundation with the aim of making obstacles easier for horses to see, and so reducing the risk of falls and injuries for horses and jockeys.

The main findings have been made available previously, but now the full report has been published in Applied Animal Behaviour Science.

Horses see colours differently from humans. Humans and other primates have three types of light-responsive cells (cones) in their eyes, giving what is called trichromatic colour vision. Normal human eyes detect four basic colours: red, green, yellow and blue. They can also differentiate up to 100 subtle variations in hue. Humans with red-green colour vision defects can only see two basic colours - yellow and blue.

Proposed new colours to make jumps more visible to horses

Horses, as with other non-primate mammals, have only two types of cone, giving them dichromatic vision. The colours seen by the horse are likely to be like those seen by humans with red-green colour blindness.

Currently, orange is used on hurdle frames and fence take-off boards and guard-rails. Although this makes the fences stand out to human eyes, it is unlikely that it makes the obstacle more visible to horses.

The study, conducted by Dr. Sarah Paul and Professor Martin Stevens of the Centre for Ecology and Conservation, University of Exeter, looked at the visibility to horses of a range of colours, and then examined the horses’ response to the presence of different colours on racecourse fences.

They analysed the contrast of traditional orange markers currently used on fences from 11 UK racecourses, and compared this to possible alternatives: yellow blue and white. They also investigated how light and weather conditions affected contrast. 

The researchers found that yellow, blue, and white were more conspicuous against fences and their surroundings (foreground/background) than orange. 

Highly luminant whites or blues at the base of the fence (take-off board) gave the best contrast, while fluorescent yellow gave the greatest contrast against the main fence body (i.e. when used for midrail colour) in different light and weather conditions.

Paul and Stevens then tested the jumping responses of horses to fences with orange, yellow, blue, or white take-off boards and guard rails.

They found that the colour of the fences could influence both the angle that horses jump a fence and the length of the jump. Horses adjusted their jump angles with colours other than orange, and white tended to produce a longer total jump distance.

The researchers suggest that the optimum colour combination, which is likely to combine the best features of visibility and horse responses under a range of conditions, is to use fluorescent yellow for all hurdles and guard-rails, and fluorescent white for take-off boards. This maximises visibility under all conditions while potentially facilitating better behavioural responses.

In response to this study, a recommendation was approved by the sport's Racecourse Committee for a trial using fluorescent yellow for all hurdles and guard-rails, and fluorescent white for take-off boards at fences. 

For more details, see:

Horse vision and obstacle visibility in horseracing.

Paul SC, Stevens M.

Appl Anim Behav Sci. 2020:104882.

doi:10.1016/j.applanim.2019.104882